This book describes the importance of the oat crop to sustainable farming and the pivotal role
that oat breeders have in this. It describes the outcomes from the author’s contribution to the
oat breeding program run by the New South Wales (NSW) Department of Agriculture from
1957 to 1974, including oat line and variety breeding and testing. The book covers the
development of high yielding, dual-purpose grazing and grain oat varieties, and the methods
used to breed and test these varieties, including trial results up to the present day. Some of this
work was published in 1961, 1965, 1966, 1992 and in 2003.
Chapter One introduce the role that oats play as an important role in human and livestock
nutrition, and as such, an understanding of the genetics of oats is significant in world
agriculture and economics. Oats provides grain for humans and livestock, a grazing or forage
crop for livestock, as well as the ability to provide combined grazing and grain production.
While the significance of the oat grain in benefiting human health has received considerable
attention in the past decade, relatively little attention has been given to this important attribute
of combined grazing, grain production and total crop value in the research and extension
literature. This reflects a lack of awareness of the full potential of the oat crop. Based on the
recent findings of FAO studies, the world supply of agricultural produce is meeting the
demands of the current world population. The total world production of cereals increased at
an annual rate of 1.45% over the period of 1981-1990, while total meat production increased
at an annual rate of 2.87%. These trends suggest that increased cereal crop yields have
allowed for an increase in the area available for pasture and hence livestock production.
Improving the total quantity and quality of world pasture production is therefore becoming
increasingly important for meeting the corresponding increases in global food demands. The
oat crop has a sigficant role to play in this increase in pasture production.
Chapter Two describes how oat breeding has led to the development of oat varieties for
the 3 main climatic regions of Australia. These three climatic regions or zones also exist
in the state of New South Wales (NSW). These three regions are as follows: The subtropical
climate zone, also referred to as the summer rainfall zone, and also occurs on
the coastal areas of Southern Queensland and Northern NSW (including Grafton, where
a crown rust nursery is located). The uniform rainfall climate zone which covers the
inland area of NSW from as north as Dubbo to Temora in southern NSW. The winter
rainfall climate occurs south of Temora and includes the Australian states of Victoria,
Tasmania, South Australia and Western Australia. An inventory of oat cultivars and their
pedigrees is presented in relation to the climatic regions in which oats are grown in Australia.
4. ABOUT THIS BOOK AND
THE AUTHOR’S OAT VARIETIES
In reviewing “Development of High-Vigour Oat Varieties in Australia”, I considered that it
was a very full and well documented account of oat breeding and testing in New South Wales
in the latter half of the twentieth century. In correspondence with a research agronomist, who
also runs a property in Northern NSW, she stated “---- Blackbutt (bred by the Author, P. M.
Guerin) has stayed a very strong variety for a very long time. The quality of the breeding is
reflected in its longevity as a preferred variety---”. I think that everyone interested in the oat
crop whether researcher, advisory officer, producer or plant breeder should read, study and
learn from this important book.
Professor Haydn Lloyd-Davies
Former Professor of Pastoral Science in the School of Wool and Pastoral Science,
University of New SouthWales
Past President of the Australian Society for Animal Production (NSW Branch)
& Author of “Animal Production”
This book discusses the evolution of oats as a crop in Australia, emphasising its versatility
and value to farmers and to the agricultural sector. In particular, it sets out the importance of
dual-purpose oat varieties in Australian agriculture, which are of significant value to this day.
As the prime lamb industry in Australia continues to expand, and in a sense is about to “take-
off”, dual-purpose oat varieties will play a significant part in the expansion of this industry.
This is a book that had to be written. I believe the book illustrates clearly what a visionary the
Author was in developing the oat varieties and lines he did.
Norm Markham
Former District Agronomist (25 years),
New South Wales Department of Primary Industries
(formerly NSW Department of Agricutlure),
& Independent Agricultural Consultant currently based in West Wyalong, NSW, Australia
“Reading Patrick Guerin’s book reminded me of times, as a research agronomist on the
Southern Tablelands. There I conducted numerous experiments on the effects of winter
grazing of cereals and other crops, on vegetative yield, animal production and subsequent
grain yields. This work was published in the Australian Journal of Experimental Agriculture,
its predecessor and elsewhere. Guerin’s variety Blackbutt was always the stand-out crop for
maximum combined forage and grain production, particularly in the severe winter
environment of the Tablelands”
“Congratulations, Paddy, on an important publication”
Paul Dann
Former Research Agronomist, NSW Agriculture
5. Having witnessed oats being successfully grazed on a family property at Lyndhurst in Central
West NSW, and having already been convinced of the health benefits of oats as a human
breakfast staple, it was a great pleasure for me to study each absoprbing, and very readable
chapter. Without closing the door on gene technology as a way forward, his highlighting of the
challenges, Patrick is convincing in his support of the Isolection Medelian plant breeding system.
Bob Fozzard, Sydney, Australia
Member of the Australian Institue of Agricultural Science and Technology
“I started growing Carbeen at our property in mid 1980’s. We like to start sowing in February.
We often have a dry March – April and on these occasions, other varieties will run to head,
whereas Carbeen doesn’t and it recovers well. With the quantity of leaf material and its
prostrate growth, our sheep can keep grazing for a longer time compared to erect growing oat
varieties. If Carbeen is eaten out early, its recovery is good. When we grow Carbeen for grain,
then a sowing rate of 30 kg/ha will yield up to 2.9 t/ha, and that is under continuous grazing”.
“Carbeen is a variety well suited for growing in the Tamworth region of New South Wales”.
John McQueen
Farmer
“Colindale”, Loombenah,
New South Wales, Australia
“I grew Blackbutt in the very early 1980s, switching over from Cooba which my father had
grown for years. My early memories of harvesting Cooba were with a comb front harvester,
sometimes with croplifters, which was nightmarish! We noticed straight away that with
Blackbutt that it had more tillers and the plants were very hardy, able to withstand the often
dry autumns that we endure on our farming area. Blackbutt was fairly prostrate in early stages
but with late autumn rain, it emerged into a massive bulk of feed in the winter months”.
“We continued to grow Blackbutt until we heard of another one, of related breeding, called
Carbeen. A friend had been growing it for a few years. We gave it a go and have been
growing it ever since. Some of the characteristics of Carbeen have been its ability to
withstand lodging in all but the very lushest of seasons, its ability to put out lots of tillers
when sown early, and when these become erect later, they have a very nutritious broad leaf
that our stock thrive on.
“I am so happy with the production levels from Carbeen that I have not even tried the new
varieties or even winter wheats as I really don’t think they could be any better than what I
have seen with Carbeen”
Paul McCulloch
Farmer
“Danibe”, Tamworth
New South Wales, Australia
6. ABOUT THE AUTHOR
The Author was born in Chile in 1928, of an
Irish father and an English mother. He graduated
with a Bachelor of Agricultural Science from
National University of Ireland, Dublin, in 1952.
From 1950 he became an amateur beekeeper and
from 1952 to 1955, he was a Milk Costings
Officer for the Irish Department of Agriculture.
He then became Lecturer in Chemistry and other
agricultural subjects at Warrenstown
Agricultural College, Co. Meath, Ireland.
He was then an Abstractor for Herbage and Field
Crop Abstracts for the Commonwealth
Agricultural Bureau (CAB) at Maidenhead,
England from 1955-1956. In 1956 he was
appointed Plant Breeder for NSW and
permanently moved to Australia. In Australia,
the Author was an oat and linseed breeder from 1956 to 1964, stationed at Glen Innes with
NSW Agriculture. Using both established and original techniques, the Author bred Australia’s
most frost resistant and productive winter grazing cereal variety, Blackbutt oats. The Author
developed the Isolection system of plant breeding, a technique for producing High-vigour oat
varieties. Using this system, he made a High-vigour cross in 1957, from which he bred and
selected P4315, as well as Blackbutt oats, as well as numerous other oat verities. Blackbutt
and P4315 both broke world records for yield in 1973. From 1972 until 1985, he engaged in
farming near Temora, NSW, giving his 7 children experience of a farming lifestyle.
He produced wheat and forage crops and managed sheep, cattle, and high quality pigs for
bacon. He then retired to the Sydney region of NSW to return to study and writing. The
subjects he studied included plant breeding, genetic engineering, languages, philosophy,
physical anthropology, prehistory, celtic and religious studies, theology, and history. Patrick
currently lives in Lithgow, NSW.
7. CONTENTS
List of Tables 1
List of Figures 3
Preface 6
Acknowledgments 8
Chapter 1 Introduction 9
Chapter 2 Australian Oat Varieties And A Germplasm
Inventory For Breeding
37
Chapter 3 The New Isolection Plant Breeding System 62
Chapter 4 Breeding Oats For Irrigation In Australia 104
Chapter 5 The Influence Of Environment
On Oat Grain Quality
115
Chapter 6 Plant Breeding Methods And Technologies
For Increasing Oat Crop Yields
124
Glossary 137
Appendix A Australian Oat Statistics 150
Appendix B Plots From A Heavy Grazing Trial 154
8. - 1 -
LIST OF TABLES
Table 1.1 Chemical composition of oats 10
Table 1.2 Comparative feed grain values of oats, barley, wheat and maize 11
Table 1.3 Percentages of nutritive values in oats, barley, wheat and maize 16
Table 1.4 Species of Avena genus, the 3 karyotypes and their genomes 18
Table 1.5 World population densities 22
Table 1.6 Food production and population growth 23
Table 1.7 Changes in total grain yields and reduction in total crop growing area 24
Table 1.8 Annual rate of change (%) of increase in production of farm products 25
Table 1.9 World land utilisation 27
Table 1.10 Oat yields, growing days, population density and agricultural policy 28
Table 1.11 Stocking capacity of oats compared with other pastures 29
Table 2.1 Effect of grazing oats twice, versus no grazing, on grain yield of
various cultivars
39
Table 2.2 Summer rainfall germplasm 47
Table 2.3 Uniform rainfall germplasm 49
Table 2.4 Winter rainfall cultivars 50
Table 2.5 Crosses combining rust resistance with agronomic value 51
Table 2.6 Segregation in landraces for juvenile growth habit, Glen Innes 1958 51
Table 2.7 Resistances for various environments 52
Table 2.8 Origin and description of genotypes developed from the High-vigour
cross, 28 X 23
53
Table 3.1 Rapid method of breeding oats for large biomass yields 64
Table 3.2 Morphology and pathology of parents of the High-vigour cross 65
Table 3.3 The effect of grazing intensity on a range of cereal genotypes sown late
March in a cool, moist, summer rainfall climate: F6 generation trial of
High-vigour lines (1962)
69
Table 3.4 The effect of grazing intensity on a range of cereal genotypes sown in
early March in a cool, moist summer rainfall climate: F7 generation
trial of High-vigour bulk oats (1963) at Glen Innes
70
Table 3.5 Second testing of High-vigour bulk oats in north-west NSW, contrasting
cooler elevated site (Tamworth) with warmer plains site (Narrabri):
F5 generation trial (1961)
76
Table 3.6 A comparison of southern and northern NSW bred cultivars under
intensive grazing and hay recovery: F10 generation testing of
High-vigour lines at Richmond (1966)
77
9. - 2 -
Table 3.7 Heavy (4 P cuts) and lenient (2 P cuts) grazing and grain recovery (pG)
at Cowra: F10 generation testing of the High-vigour lines (1966)
83
Table 3.8 Lenient grazing and grain trial: F17 generation testing of High-vigour
bulk oats
84
Table 3.9 Effect of multiple grazing cuts on grain and pasture yields on a range
of oat cultivars
85
Table 3.10 Grain and pasture yields from 1955 competing crop trials 86
Table 3.11 Effect of a single grazing, grain recovery, total yield and grain protein
(%) on a range of oat cultivars
89
Table 3.12 Effect of two grazing cuts on grain recovery and pasture yields on a
range of oat cultivars
90
Table 3.13 Dry matter of pasture and grain recovery trial, Gunning, NSW (1999) 91
Table 3.14 Grain yields from competing a cereal crop trial conducted in
New England
91
Table 3.15 A continuous grazing (P) and grain recovery (pG) trial in Central
NSW; F34 generation testing of High-vigour varities (1990) at Blayney
92
Table 3.16 Effect of two grazing cuts and grain recovery (Site 1) and grain only
(Site 2) on a range of oat cultivars
94
Table 4.1 NSW cereal crop yields under dryland and irrigation (t/ha) 105
Table 4.2 Comparisons of early and late maturing cultivars under Irrigation in the
Riverina for a 10 year period for grain only (G), and grain recovery (pG)
(1963-1973)
109
Table 4.3 Comparisons of grain only (G) yields and grain recovery (pG) in the
Dryland Riverina for a 10 year period (1963-1973)
110
Table 4.4 Year 24 of testing Blackbutt oats under irrigation versus dryland
(1985): F29 generation trial
111
Table 5.1 Grain quality, as groat (gt %), of Australian cultivars and accession lines 117
Table 5.2 Oat grain quality, as weight in grams of 1000 seeds (groat + hull) and
as groat %, of cultivars at four sites in Northern NSW
118
Table 5.3 Grain quality of mainly High-vigour oats (Cross C and Cross A,
28 x 23), F7 generation testing
119
Table 6.1 Isolection-bred versus conventionally-bred oat varieties
(Richmond, NSW)
130
Table 6.2 Isolection-bred versus conventionally-bred oat varieties
(Southern Highlands NSW)
131
Table 6.3 Yield ratios of Isolection-bred to conventionally-bred oat variety
(Cooba) across climatic zones from statistically analysed trials over a
29 year period
132
Table 6.4 Comparing features of GM crops with conventional crops 134
10. - 3 -
LIST OF FIGURES
Figure 1.1 Statistical yields of the major cereals grown in NSW 32
Figure 2.1 Straw strength of various lines and cultivars. Fulghum (F) showing
lodging; weak strawed Belar; strong strawed Garry, VRBke.F
(W4598); strong strawed Fulmark
42
Figure 2.2 Climatic regions of Australia 45
Figure 2.3 A transect of NSW showing the Northern, Central and Southern regions
in NSW approximating summer rainfall, uniform rainfall and winter
rainfall zones, respectively
46
Figure 2.4 BLACKBUTT variety with medium panicle shape and light brown
grains: the longest grazing season cultivar of Australian winter cereals.
Photograph is from Australian Oat Varieties by R.W. Fitzsimmons et
al. CSIRO (1983)
47
Figure 2.5 COOLABAH is an early grazing and grain variety with medium
panicle shape and cream coloured grains. It is too frost susceptible for
the summer rainfall germplasm list. Photo is from Australian Oat
Varieties by R.W. Fitzsimmons et al. CSIRO (1983)
49
Figure 2.6 ORIENT is an erect early midseason variety for grain only, with
medium to open panicle and dark brown grains. It is too frost
susceptible for the summer rainfall germplasm list. Photograph from
Australian Oat Varieties by R.W. Fitzsimmons et al. CSIRO (1983)
50
Figure 2.7 ALGERIAN variety with open panicle and mid-brown grains from
Australian Oat Varieties by R.W. Fitzsimmons et al. CSIRO (1983).
Table 6.5 shows that both Algerian and Fulghum were segregating for
juvenile habit of growth in the 1958 F2 summer rust nursery,
confirming Coffman’s claim that the related varieties of Red Rustproof
and Kanota in the USA could not be fixed
51
Figure 2.8 COOBA is a mid-season grazing and grain variety with open panicle
and mid brown grains from Australian Oat Varieties by R.W.
Fitzsimmons et al. CSIRO (1983). Cooba is inferior to Blackbutt and
Carbeen for grazing and frost resistance in the summer rainfall zone
52
Figure 2.9 CARBEEN variety with condensed panicle shape and medium brown
grains. A mid-season variety with prostrate early habit of growth, the
most adaptable to the 3 rainfall zones. Photograph from Australian Oat
Varieties by R.W. Fitzsimmons et al. CSIRO (1983)
53
Figure 2.10 FULGHUM spiklets and florets from Oat Identification and
Classification by T.R. Stanton (1955) US Department of Agriculture
Technical Bulletin No. 1100. Fulghum is a semi-winter type and
appears to be of hybrid origin, with many traits intermediate between
the northern common oats, A. sativa, and the southern red oats,
A. byzantina, as judged by observers in the US
54
11. - 4 -
Figure 2.11 FLORET SEPARATION distinguishes the 2 types of cultivated oats
which are Avena sativa, separating by distal fracture, and A.byzantina,
usually separating by basal fracture. Photograph from F.A. Coffman,
Inheritance of Morphological Characters in Avena, Technical Bulletin
No. 1308, Agricultural Research Service, United States Department of
Agriculture
54
Figure 2.12 MORPHOLOGICAL CHARACTERISTICS OF THE OAT PLANT,
showing panicle and spikelet, main rachis and panicle branches;
rachilla and basal hairs of mature grain; spikelet showing pedicel,
glumes, rachilla, primary grain and secondary grain and awn on the
primary grain; culm nodes and nodal hairs and leaf margins and leaf
sheaths, both hairy and glabrous. From Anonymous (1962)
55
Figure 2.13 The Author assessing mature oat crop stands. Avon x VRFB;
Garry x VRBke (2056) and Fulghum (see summer rainfall germplasm
inventory)
56
Figure 2.14 Mature oat crop stands. The Author with a tall strong strawed line;
Avon (see the uniform rainfall germplasm inventory) and taller W4477
57
Figure 3.1 Results of heavy grazing by sheep; The pasture cut technique using
manual shears at Glen Innes, NSW
74
Figure 3.2 Tall strong straw of Fulghum (F) x Garry (Ga) (F.Ga or W4595),
typical of the F.Ga cross; Close up of the panicles of F.Ga, the female
parent of the High-vigour cross
75
Figure 3.3 Non-stress growing environment. A plastic covered frame for
establishing rust infected plants, transplanted from the subtropical
station at Grafton, and designed to spread rust and determine rust
resistant plants; Inspection of individual oat plants
78
Figure 3.4 Non-stress growing environment Fulghum x Garry (female parent of
the High-vigour cross showing) showing its strong straw; Wide
spacing of individual oat plants
79
Figure 3.5 Crossing of a rust resistant line, of oat, 0600 and VRAF (W4890) 80
Figure 3.6 A typical Western Australian bred cultivar, Swan, showing poor dry
matter recovery under a 5 grazing cut regime at Temora, New South
Wales, 1969, in comparison with moderately frost-hardy Cooba and
very frost-hardy P4315
82
Figure 3.7 The Author shows greater damage to Algerian from a combination of
frost and grazing pressure than that to Klein 69B the Argentine oat,
which showed excellent frost resistance and grazing recovery almost
equal to Blackbutt; The Author shows poorer performance of Algerian
compared to High-vigour line P4314. Further images of the grazed
plots at Hawkesbury Agricultural College trials in Richmond NSW
in 1966, are presented in Appendix B
95
Figure 3.8 A comparison of the five selections from the High-vigour cross for
total biomass yield (P + pH) with conventionally bred cultivars at
Hawkesbury Agricultural College, Richmond, NSW (1966)
96
12. - 5 -
Figure 3.9 A comparison of a standard cultivar, Algerian, with five selections
from the High-vigour cross, with 5 separate pasture cuts at
Hawkesbury Agricultural College, Richmond, NSW (1966).
The extent of the grazing is shown in individual plots within the trial
presented in Appendix B
97
Figure 3.10 The Author at Temora Agricultural Research Station taking notes near
seed increase blocks. Selecting hardy, productive and rust resistant
dual-purpose oats by wide spacing of plants in the Author’s Isolection
breeding system, produced P4315, Blackbutt both from the same
High-vigour cross; Mugga, also bred by the Author, is the hardiest of
the oats tested in Glen Innes NSW, equivalent hardiness to winter
wheat. Mugga was selected from VRBop x Belar
99
Figure 4.1 A diagrammatic comparison of eight cultivars under irrigation
(grain only) and cool dryland (grain recovery) in t/ha (Colleambally,
NSW in 1985)
112
Figure 5.1 Grain shape and sizes of the parents of the High-vigour cross 120
Figure 5.2 Grain shape and sizes of the High-vigour varieties and lines (Blackbutt,
Carbeen and P4315) alongside conventionally bred cultivars
121
13. - 6 -
PREFACE
“An economic oat breeding program will only succeed in proportion to the breeder's skill and
knowledge in being able to consider the project as a whole, rather than as separate entities”
J.G. Carroll (1951)1
This book describes the importance of the oat crop to sustainable farming and the pivotal role
that oat breeders have in this. It describes the outcomes from the author’s contribution to the
oat breeding program run by the New South Wales (NSW) Department of Agriculture from
1957 to 1974, including oat line and variety breeding and testing. The book covers the
development of high yielding, dual-purpose grazing and grain oat varieties, and the methods
used to breed and test these varieties, including trial results up to the present day. Some of this
work was published in 1961, 1965, 1966, 1992 and in 2003.
Chapter One introduce the role that oats play as an important role in human and livestock
nutrition, and as such, an understanding of the genetics of oats is significant in world
agriculture and economics. Oats provides grain for humans and livestock, a grazing or forage
crop for livestock, as well as the ability to provide combined grazing and grain production.
While the significance of the oat grain in benefiting human health has received considerable
attention in the past decade, relatively little attention has been given to this important attribute
of combined grazing, grain production and total crop value in the research and extension
literature. This reflects a lack of awareness of the full potential of the oat crop. Based on the
recent findings of FAO studies, the world supply of agricultural produce is meeting the
demands of the current world population. The total world production of cereals increased at
an annual rate of 1.45% over the period of 1981-1990, while total meat production increased
at an annual rate of 2.87%. These trends suggest that increased cereal crop yields have
allowed for an increase in the area available for pasture and hence livestock production.
Improving the total quantity and quality of world pasture production is therefore becoming
increasingly important for meeting the corresponding increases in global food demands. The
oat crop has a sigficant role to play in this increase in pasture production.
Chapter Two describes how oat breeding has led to the development of oat varieties for
the 3 main climatic regions of Australia. These three climatic regions or zones also exist
in the state of New South Wales (NSW). These three regions are as follows: The sub-
tropical climate zone, also referred to as the summer rainfall zone, and also occurs on
the coastal areas of Southern Queensland and Northern NSW (including Grafton, where
a crown rust nursery is located). The uniform rainfall climate zone which covers the
inland area of NSW from as north as Dubbo to Temora in southern NSW. The winter
rainfall climate occurs south of Temora and includes the Australian states of Victoria,
Tasmania, South Australia and Western Australia. An inventory of oat cultivars and their
pedigrees is presented in relation to the climatic regions in which oats are grown in Australia.
The inventory tables list the name or accessional line of the oats, their pedigrees and breeder.
A description of the Austalian oat ideotype is also proposed.
Chapter Three described the results of 34 years of oat breeding and testing of dual-purpose
varieties (for grazing and grain recovery) by the NSW Department of Agriculture are
summarised in this chapter. A High-vigour cross (HvII 57-75) is identified which led to the
1
From a NSW Department of Agriculture Internal Report. James Carroll was a plant breeder dedicated to oats,
potatoes and gladioli.
14. - 7 -
release of Blackbutt (an F4 directed bulk type) in 1975, and Carbeen (an F6 plant progeny of
the normal pedigree system) in 1981. This High-vigour cross also produced a number of high
yielding F4 directed bulk types and F2 plant progenies bulked in the F3 as a result of their
relatively high phenotypic uniformity. The highest yielding F3 bulk was numbered P4315,
which although classed as an early oat, out-yielded all other varieties, including Blackbutt, for
total biomass, following early sowings, and over a wide range of soils and climates and a
great many seasons. The success of these oats was due to the Isolection plant breeding
system pioneered by the Author at Glen Innes from 1957 to 1964. Other F4 directed bulks
were P4314 (high-yielding both as a winter oat and a spring oat at Glen Innes) and P4318,
both of which had large grains and, together with Blackbutt and P4315, were significantly
superior over 5 grazing cuts (including the mid-winter cut) to Coolabah and all other
advanced lines submitted by plant breeders from Temora NSW, that were using conventional
breeding methods during the same period. Selection of lines at the F2 generation has been
demonstrated as a simple way of forecasting wider adaptability of early generation material.
Chapter Four describes why Glen Innes, on the New England Tablelands in NSW, has proven
to be the best centre for breeding oats for the heavy soils of the Riverina at Leeton,
southwestern NSW. Plant selections made on the black self-mulching soils of the Glen Innes
Research Station of northern NSW have resulted in the varieties Acacia, Bundy, and Mugga;
all now replaced by Blackbutt. Both areas require resistance or tolerance to stem rust, water
logging, red-legged earth mites, BYDV, lodging, shattering and second growth. Although
frost damage is less of a problem in the irrigation areas than on the northern tablelands of
NSW, the frost resistant bulks from the cross F.Ga x VRAF.VRSF demonstrated good
tolerance to water logging on heavy soils. Blackbutt also excelled as both a dual-purpose and
a grain only variety and is recommended for both northern and southern irrigation areas.
Chapter Five describes the important influence of the oat growing environment on oat grain
quality. Oat grain quality (grain weights per 1000 seeds and groat percentages) was found to
be an effective measure of the environmental stress imposed on an oat variety at a particular
geographical and climatic centre. The results of various oat trials conducted across NSW
show that the environment has an effect on the maturation and filling of the oat grain. The
results compiled by the Author suggest that northern NSW (i.e. the summer rainfall zone)
could be further sub-divided into 5 climatic regions, from east to west, for the purpose of
recommending oat varieties. Glen Innes, at an elevation of 1,128m and latitude 29° 42” S. on
the New England Tablelands, proved to be the ideal climate for developing high groat
percentage and large grain size. A sixth climatic zone, located in Leeton, NSW (uniform
rainfall zone), at elevation at 152m and latitude 34° 33” S., was the second most favourable
centre, but required irrigation for full grain development.
Chapter Six discusses plant breeding methods and technologies and their potential for
increasing oat crop yields and oat crop improvement. It specifically introduces the importance
of hybrid vigour and a non-stress environment for higher percentage heritability selection and
therefore providing a more productive conventional plant breeding method for the
improvement of crops. This chapter draws together the results from trials presented in
Chapters Three and Four to show the superiority of the Isolection method over the
conventional oat breeding method for development of high yielding, multi-purpose oat
varieties. GM technology and crops derived from cloning, a process devoid of hybrid vigour,
are compared with proven plant breeding methods.
15. - 8 -
ACKNOWLEDGMENTS
The Author is indebted to his colleagues from the NSW Department of Agriculture; the late
Dr F. Mengersen, oat breeder, for generously sharing his knowledge; Farm Manager Messrs.
Eric Powell, the Farm Manager at Glen Innes, who made the Author welcome and at ease
during the first years of his settling in Australia. He fondly remembers fellow agronomists,
Martin Bellert of Queensland and the late Milton Walker, both of whom were very supportive
in this work; Ern Tindale and Jack Loveridge for providing the fertile seed-beds so necessary
for genetic gains in the oat crop; Mr. I. Cole for pure seed production; Mr. Bill Uppsdell and
Mr. Jack Stapleton for maintaining the link of pedigree records; the oat germplasm and
uniform techniques from pioneer oat breeders, the late Dr S. L. Macindoe and Mr. J. C.
Carroll, previously of Glen Innes Station; District Agronomists, Agronomists-in-training and
all personnel, past and present, involved in the NSW Agricutlure oat breeding and testing
program.
The Author also acknowledges other Australian agronomists, completely unknown to him,
who carried out complex grazing experiments with his Blackbutt, P4315 and Carbeen
(selected by Mr. Glenn Roberts of Temora Research Station), all cultivars from the High-
vigour Cross, and had them published in scientific journals. Some of these people included
Mr. Muldoon, who found Blackbutt to be the best variety, physiologically, for total grazing
and grain of any winter cereal, under irrigation at Trangie; Mr. McLeod and Mr. Ramsey,
who found Blackbutt and Carbeen were the highest producers of total grazing and grain after
4 grazings at Bendigo, Victoria; Mr. Craig and Mr. Potter found that Carbeen was the only
variety at Kybybolite, South Australia, which increased its grain yield after 2 grazings. The
Author also acknowledges the efforts of Mr. G. Hennessy, who obtained a world grain yield
record for P4315 oats (an early maturing sister-line to Blackbutt) of 20 tonnes per ha,
following two grazings, at Tamworth Research Station in 1973.
The Author is grateful to his son, Dr. Turlough Guerin, for co-authoring and organizing two
articles for the 1992 International Oat Conference at Adelaide, as well as for criticism, co-
ordinating reviews, editing and assistance in putting this book together.
The Author is also grateful to Mr. Roger Fitzsimmons, who retired as Assistant Principal
Agronomist of Cereals in the NSW Department of Agriculture, for collating trial results,
reading and correcting the manuscript and for valuable advice from his long experience.
The critical reviews provided by several agricultural scientists are kindly acknowledged
including those provided by Professor Haydn Lloyd-Davies, Professor Peter Ruckenbaur,
Professor Frank Crofts, Paul Dann, Norm Markham, Wayne Vertigan, Bob Fozzard and Andy
Roberts. Dr. W. Jim Althom is also acknowledged for his review of a final draft of the
manuscript.
16. - 9 -
CHAPTER ONE
INTRODUCTION
Oats play an important role in human and livestock nutrition, and as such an understanding of
the genetics of oats is significant in world agriculture and economics. Oats provides grain for
humans and livestock, a grazing or forage crop for livestock, as well as the ability to provide
combined grazing and grain production. While the significance of the oat grain in benefiting
human health has received considerable attention in the past decade, relatively little attention
has been given to this important attribute of combined grazing, grain production and total
crop value in the research and extension literature. This reflects a lack of awareness of the full
potential of the oat crop. Based on the recent findings of FAO studies, the world supply of
agricultural produce is meeting the demands of the current world population. The total world
production of cereals increased at an annual rate of 1.45% over the period of 1981-1990,
while total meat production increased at an annual rate of 2.87%. These trends suggest that
increased cereal crop yields have allowed for an increase in the area available for pasture and
hence livestock production. Improving the total quantity and quality of world pasture
production is therefore becoming increasingly important for meeting the corresponding
increases in global food demands. The oat crop has a sigficant role to play in this increase in
pasture production.
INTRODUCTION
The importance of the oat crop in human and animal nutrition has been established only
relatively recently. Studies demonstrating the cholesterol lowering effect of oat bran and other
oat products in laboratory animals and humans have been known since the early 1990s. This
has been attributed to the high soluble fibre (β-glucan) content of oats and oaten bran,
confirming traditional beliefs in the value of oats, relative to all other cereals. Knowledge of
β-glucan, oil and protein contents of oat varieties, in various germplasm collections, will
enable breeders to add value to all agronomically useful varieties for optimum human and
animal nutrition.
The nutritional and health qualities of the oat crop are of considerable importance in
establishing the context for this book and these attributes are discussed in this chapter. A brief
introduction to oat genetics and the origin of the oat crop is also provided as well as a
discussion of the broader agricultural and economic significance of this crop globally.
OAT GRAIN QUALITY AND HEALTH
Overview
Research has identified oats as the health grain for humans and animals (McDonald et al.
1992). There are active components in oats which lower blood lipids, regulate blood glucose
and protect against tumour development in the colon.
17. - 10 -
The cholesterol-lowering benefits of oats have been attributed to ß-glucan in the oat fibre
fraction. Oat bran and oatmeal supplementation studies show a more favourable effect on
blood glucose and insulin responses than other cereal grains like wheat and maize. Oat
soluble fibre should delay the onset of fatigue and enhance athletic performance. Besides
addressing major diseases of wealthy nations, like coronary heart disease, cancer and
diabetes, oats could provide benefits for blood pressure and weight reduction.
Oats also contain a high proportion of monounsaturated fat, antioxidants such as tocotrienols,
and an amino acid composition rich in arginine relative to lysine. Antioxidants have been
linked to reduced risk of cancer, heart disease and degenerative changes in the eye as well as
to increased immune function (Bunce et al. 1990; Diplock 1991).
Coeliac disease in human individuals, sensitive to gluten and unable to eat wheat, barley or
rye (all high in gluten) can, usually, safely eat oats which contains only trace quantities of the
gluten protein (Welsh, 1995).
Table 1.1 shows the marked superiority of oat bran over rolled oats both in protein and in
dietary fibre, contrary to popular uninformed opinion which formerly regarded oat bran as
less valuable.
Table 1.2 compares feed grain values of the 3 winter cereals and maize. It should be noted
that high fibre in oats goes hand-in-hand with a high oil content. The oil composition in oats
is high in linoleic acid and low in linolenic acid.
Oat hulls are very effective in inhibiting the development of dental caries in animals at dietary
levels of 3 to 25%. Phenolic compounds in the hulls may involve antioxidant or antimicrobial
activity (Madsen, 1981).
Table 1.1 Chemical composition of oatsa
.
Nutrients Rolled Oats Oat Bran
Energy 1600 kJ 1030kJ
Protein 10.5 17.3
Fat, total 8.0 7.0
Fat, saturated 1.5 1.2
Carbohydrates 61 50.3
Sugars 0.0 2.6
Dietary fibre 10.0 15.9
Sodium < 5.0 < 5.0
Thiamine (B1) - 1.2 mg
a
From BiLo (2004). Values given grams per 100 grams.
18. - 11 -
Table 1.2 Comparative feed grain values of oats, barley, wheat and maizea
.
Nutrients Oats Barley Wheat Maize
Protein (%N x 6.25) 10.5 11.0 12.5 10.4
Oil (%) 5 2 2 4
Crude fibre (%) 10 5 2 2
GEb
(MJ/kg DMd
) 19.6 18.5 18.7 18.9
MEc
(ruminants) 12.0 12.9 13.5 13.8
a
From Welsh (1986); b
GE. = Gross energy; c
ME. = Metabolisable energy in ruminants; d
= dry matter.
Genes encoding the oat kernel storage proteins, avenins and globulins, have been isolated and
characterised. Oat globulins, which make up 50-80% of the kernel protein, resemble legume
globulins in amino acid composition thus explaining the nutritionally balanced amino acid
content of oat proteins. The protein of oats is unique among temperate cereals because of this
high content of globulin, which closely resembles a major seed legume protein, glycinin
(Peterson and Brinegar, 1986). Therefore oat and legume proteins may have similar
hypocholesterolaemic properties. These properties or cholesterol reducing effects are higher
in oat bran than in rolled oats. Thus, Ripsin et al. (1992) took 3g of soluble fibre to be
equivalent to 42g of oat bran or 84g of oatmeal. This superior effect of oat bran suggests that
there is a role for both the gum and the protein since both these components are higher in the
bran. The major component of oat gum is β-glucan.
Oats have long been the breakfast cereal of the Celtic people of Ireland, Scotland, Wales and
the cooler, wetter northern counties of England, the North American, Scandinavian, North
European and Slavonic peoples. More recently, the crop has spread to West Africa and is
likely to become universally important with its unique value for the health of humans and
animals, relative to other grains.
Composition of oat grain
Oats have a slightly sweet, slightly sour taste, which does not require the addition of sugar or
honey. Oats can also be blended with a variety of other health-giving foods. To understand
the nutritional significance of oats, it is necessary to look at the various constituents of oats.
Protein. Oats have a higher concentration of well-balanced protein than other cereals and
therefore a greater potential value to provide a substantial proportion of protein requirements
than other cereals. Among the essential amino acids that make up protein quality, cereals are
generally limiting in lysine. Oat protein is higher in lysine than that of other cereals.
Lipids. Lipids are a concentrated source of energy, being higher in energy value than
carbohydrate. The lipid concentration of oats is higher than that of other cereals. The lipid
composition of oats is favourable because of the high proportion of unsaturated fatty acids.
Oats are high in linoleic acid, an essential fatty acid for human nutrition. Linoleic acid is used
in the synthesis of prostaglandins that are found in all tissues and regulates smooth muscles.
Minerals. Oats are a good source of manganese (Mn), magnesium (Mg), iron (Fe), calcium
(Ca), zinc (Zn) and copper (Cu). The major proportion (58%) of the phosphorus in the oat
19. - 12 -
kernel occurs as phytic acid. Phytic acid may bind minerals, making them unavailable in
nutrients. Rolled oats, however, did not decrease the absorption of Fe any more than did
milk, which contains no phytic acid.
Vitamins. Oats contain little or no vitamin A, C or D but it does contain small yet significant
quantities of thiamine, folic acid, biotin and pantothenic acid.
Starch. The starch concentration of oats on a whole grain basis is lower than that of rye,
barley or wheat, reflecting the relatively thick hull of oats.
Soluble sugars. Total free sugar concentration of oats is low, relative to barley, wheat and
rye, but similar to maize (Table 1.1).
Fibre. Dietary fibre is defined as plant polysaccharides and lignin, substances resistant to
human digestive enzymes. Starch is the only plant polysaccharide that is digestible by
humans. Therefore, dietary fibre includes all non-starchy polysaccharides (NSP) plus lignin.
NSP include cellulose, hemicellulose and lignin (all water insoluble), whereas other fibre
components are classified as soluble. The solubility factor is important for understanding the
importance of oats for human nutrition (Shinnick et al. 1988).
The significance of oat fibre and human health
Whole oats, before processing, have 20-37% fibre. After processing, the oatmeal has about
12% fibre, while the oat bran, the coarse milling fraction, contains about 18% dietary fibre.
The dietary fibre of oats is a mixture of soluble and insoluble fractions and the soluble
fraction is high relative to other cereals due to the high concentration of ß-glucans in oats.
The irregular configuration of these polymers makes them partially water soluble and
functionally different from cellulose in the human digestive system. Only barley exceeds oats
in concentration of ß-glucans, but a higher proportion of oat ß-glucan is soluble. There is a
wide range of ß-glucan concentration among diploid oat species but narrower ranges among
tetraploid and hexaploid oat species. The highest values are found in the hexaploid or
cultivated species of oats.
Oat ß-glucans are especially abundant in the bran fraction that contains the outer layer of the
caryopsis and thick cell walls of the sub-aleurone region (Henry 1987).
Cholesterol lowering properties
The cholesterol lowering properties (or hypocholesterolemic) effects of oats have been proven
in both animal and human studies. These are discussed in the following sections.
Animal studies. As early as 1963, rolled oats were found to decrease serum cholesterol level
of rats fed a semi purified diet with 10g per kg cholesterol and 2g per kg cholic acid (De Groot
et al. 1963). The hypocholesterolemic effect of oats was greater than that of other grains
tested. In other experiments, the soluble gum fraction of oat bran was the most effective in
lowering serum and liver cholesterol.
Human studies. Studies with experimental animals have been confirmed in human feeding
trials. When hypercholesterolemic male subjects were fed diets containing 140g of rolled oats
daily, their cholesterol levels were significantly lowered 11% in 3 weeks, and levels rose
again when the oat-containing diets were discontinued (De Groot et al. 1963). In another
20. - 13 -
study, an 8% drop in the serum cholesterol levels of 17 hypercholesterolemic individuals was
observed after 4 weeks of a diet containing <35% of energy from fat (Turnbull and Leeds
1987). Subsequently, the inclusion of 150g of rolled oats resulted in a further reduction of
serum cholesterol levels by 5%, whereas wheat supplementation produced no further
reduction in cholesterol. Further, in a study involving 236 subjects with normal cholesterol
levels, total cholesterol decreased 6.6% with a fat-modified diet alone and 8.3% with a fat-
modified diet plus 56g of oatmeal daily (Van Horn et al. 1988). This study showed that
oatmeal or oat bran ingestion may enhance serum cholesterol reduction induced by dietary fat
modification both in individuals with high cholesterol and healthy levels.
Hypotheses to explain cholesterol lowering by oats. There are several theories as to how oats
lead to lowering of cholesterol.
The value of oat soluble fibre has been explained by dietary cholesterol absorption, bile acid
reabsorption, production of lipoproteins in the liver and removal of lipoproteins in peripheral
tissues (Anderson and Gustafson 1988).
The presence of oat products in the small intestine increases the viscosity of the intestinal
contents, leading to a slower rate of dietary cholesterol absorption, thus reducing its
availability and increasing faecal excretion (Lund et al. 1989). In the same study, oat bran
diets increased the faecal excretion of bile acids in human subjects. Lower amounts of bile
acids returned to the liver may divert liver cholesterol from lipoproteins to bile acids.
However, not all soluble fibre sources that lower plasma cholesterol increase bile acid
excretion as does oat bran fibre, and the magnitude of the increase from those that do, is
small.
A further hypothesis is that oat fibre-induced short chain fatty acids inhibit cholesterol
synthesis in peripheral tissues. This would result in a surplus of low-density lipoprotein
(LDL) receptors, to increase the rate of LDL clearance. No single mechanism will explain the
effects on cholesterol concentrations of oat bran soluble fibre (Marshall and Sorrells 1992).
Further, the effects of a high-fat meal (50g fat) on healthy individuals have been shown to be
alleviated by oats. Endothelial dysfunction induced by acute fat ingestion is prevented by
concomitant ingestion of oats or vitamin E, but not wheat. As a result, Katz et al. (2001)
concluded that oats are better than wheat for cardiovascular health.
The glycemic effects of oats
Soluble dietary fibre in the diet slows the increase in blood glucose that normally follows a
meal and is important in the treatment of Type II diabetes. Ingestion of oatmeal or oat bran
decreased the glycemic index (blood glucose response relative to that induced by white bread)
and insulin response in healthy and diabetic individuals (Heaton et al. 1988).
In no insulin-requiring diabetics, oat bran and oat gum at levels of 8g of soluble fibre slowed
the rate of increase in blood glucose (Braaten et al. 1988). At 40 min, blood glucose
concentrations were significantly lower for both treatments, compared to a control (cream of
wheat), and peak glucose concentrations were delayed 30 to 40 min by both treatments.
Similar results were obtained with healthy individuals. Oat gum was as effective as guar
gum, but oat gum was tolerated better by most subjects. Oat bran with 15% ß-glucan lowered
blood glucose by 40%.
21. - 14 -
Prevention of colon cancer
The antioxidant properties of the tocotrienols and phenolic compounds in oats should inhibit
colon tumour development. In countries where the diet is associated with a low prevalence of
coronary heart disease, prevalence of colon cancer is also low (McDonald et al. 1992).
Relevance of the oat health factors to agriculture
The oat health factors are also of significance to agriculture more broadly and these are
discussed in the following sections.
Relevance to plant breeding. This book stresses the importance of dual-purpose oat breeding,
that is oats used for grazing and grain production (described in Chapters 2-6), for which the
most successful centre for NSW was at Glen Innes. There is no longer a need to grow oats
only for ease of milling. Heavily grazed oats may or may not (depending on good summer
rain) recover grain with a higher proportion of oat bran, now the most sought after health
component of the oat crop, both for humans and animals. Oat bran is of significance because
it contains a high proportion of ß-glucan.
Composition analysis shows 4.3-4.6% ß-glucan in rolled oats and 7.3-8.9% in oat bran
(Welch 1995). The lignin (insoluble fibre) component of total fibre in oat bran was 20% while
that of oatmeal was 27%, indicating total lignin contents of 3.8% and 3.3% respectively
(Shinnick et al. 1988). Within a given oat cultivar, increasing nitrogen fertility levels
increased groat (i.e. seed minus the husk) protein and groat ß-glucan (Welch et al. 1991).
There are also genotypic differences in groat ß-glucan and this can be selected for without
undesirable correlated responses (Peterson 1991). In oats, the β-glucan is found within the
bran (or the outer portion) of the groat.
Oats, belonging to the Aveneae family, have higher levels of all the essential amino acids,
namely cysteine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine,
tryptophan, tyrosine and valine, than the Triticeae family, which includes wheat, rye and
barley. Lysine tends to be the first limiting essential amino acid in cereals and lysine
deficiency is exacerbated if the protein content of a cereal is increased by nitrogen fertilizer
application. The decline in protein quality at higher protein levels is less pronounced in oats
than in other cereals. This is associated with the relative contribution of the various protein
solubility fractions to oat total protein. The prolamine fraction, which is low in essential
amino acids, is chiefly increased in other cereals, as protein is raised by genetic or
environmental changes. This accounts for the marked decline in protein quality observed in
wheat, barley or maize as protein is increased (Mossé 1968). Globulin was found to be the
major protein fraction in oats. Since the globulin fraction has a similar amino acid
composition to the total protein, the relative increase in globulins with increasing total protein
accounts for the relative stability of the amino acid composition of oats over a wide range of
protein contents (Peterson 1976). Thus, globulins account for 70-80% of the total oat groat
protein, with glutelins accounting for less than 5-10% of the total oat groat proteins.
Relevance to milk production. Friesian-cross cows were fed ad libitum on grain-based diets,
comparing barley, wheat and oats, all rolled. Although the oat-based diet had the lowest
content of dietary metabolisable energy (MJ/kg), it produced the greatest yield of milk and
milk fat. Replacing barley with oats changed the fatty acid composition of the milk, by
significantly reducing the saturated fatty acids and significantly increasing the content of
stearic and oleic acids (Moran 1986). The oat-based diet in dairy cattle therefore increases the
appeal of milk and milk products to the health-conscious consumer.
22. - 15 -
Relevance to animal feeding and production. Oats may be successfully fed to pigs, cattle,
sheep, poultry and horses. By crushing oats and feeding them to pigs, the Author, farming at
Temora from 1972 to 1985, obtained a price premium from Gilbertsons of Melbourne (meat
processors), due to the reduction in back-fat, which was high when he was feeding crushed
wheat to his pigs (both lots receiving a similar protein supplement). Oats in cow rations
produced milk fat with an increased proportion of polyunsaturated fatty acids (Martin and
Thomas 1988).
The high fibre content of whole oats limits their use to ruminants and horses, both capable of
digesting fibre. Oats is the only cereal that does not need to be processed (as by rolling) prior
to feeding to horses. For highly productive animals, naked oats have a superior nutrient
content to wheat and barley and for this reason they justify a price premium on the basis of
least-cost formulation (Valentine 1990).
Oats are the preferred grain for horses: other cereals like wheat pack too tightly in the gut,
whereas oats remain in a loose mass that can be easily digested by the horse.
The two facets of the oat crop are (1) herbage that becomes richer in protein the more
frequently it is grazed and (2) grain, which is the safest of the cereals for ruminants and farm
work horses (Whittemore and Elsley, 1976). In varying proportions, any nutritive ratio such
as 10:1 (starch:protein equivalent) for dry and resting stock or 4:1 (starch:protein equivalent)
for breeders, lactators or growers, can be easily attained. Even oaten straw, which is
nutritionally superior to that of wheat and barley, can be used for maintenance (Welch, 1986).
Oat straw is softer and more acceptable to stock than other cereal straws and has a higher
metabolisable energy content than other cereals in terms of available energy. Oats pasture is
superior to native grass-subterranean clover pasture for ewe live-weight gain (Dann et. al.
1974). For finishing prime lambs, daily live-weight gains of 400 g and stocking rates of 60
lambs per ha were reported on oat pastures (Archer and Swain 1977).
A Canadian study investigated growth performance, carcase and meat quality of pigs fed oat-
based diets containing four levels of β-glucans. No evidence of detrimental effect of ß-
glucans in oat-based diets, particularly at levels below 4%, was detected, lending support for
the inclusion of oats in finisher diets (Fortin et al. 2003).
The high quality of oat grain and especially the biological value of its protein content and
higher calcium content are both important for humans and young growing animals including
pigs (Table 1.3). For pigs, however, barley has the ideal fibre content for fattening quickly.
In summer rainfall regions, however, there is no shortage of damaged wheat. This can be
mixed with oats in a proportion to give about 5% crude fibre. Oats should be crushed prior to
preparing a balanced food ration, which should include meat offals, or some other source of
protein, for pigs.
Oats can also enhance resistance of animals to bacterial and parasitic infections. In one study,
the oral or parenteral oat β-glucan treatment enhanced the resistance to Staphylococcus
aureus and Eimeria vermiformis infection in mice. The β-glucan, extracted from oats,
significantly enhanced phagocytic activity (Yun et al. 2003).
23. - 16 -
Table 1.3 Percentages of nutritive values in oats, barley, wheat and maize.
Valuea
Oats Barley Wheat Maize
Dry matter
Crude fibre
Gross energyb
Digestible energy
Digestible protein
Lysine
Methionine +
Cystine
Calcium
Protein qualityc
86
10.0
16.9
11.4
7.7
0.37
0.40
0.07
73
86
4.8
16.0
12.7
7.7
0.32
0.27
0.04
69
86
3.0
16.2
14.0
8.3
0.28
0.38
0.03
63
86
2.0
16.2
14.5
7.3
0.26
0.25
0.02
58
a
Values based on all being 86% dry matter; b
expressed as megajoules (MJ) per kilogram of
feed; c
biological value is highest in oats due to favourable amino-acid ratios (Whittemore and
Elsley 1976).
In another livestock nutrition study, Flinn and Foot (1992) found oat grains samples ranged
from 7-12% protein. Oats with low protein were shown to inhibit microbial activity in the
rumen of grazing sheep and needed either green oat pasture or a protein supplement.
All of the varietal samples determined by Craig and Potter (1983) were 12% protein or over in
a South Australian study study assessing the effects of grazing on various oat varieties.
Carbeen, a prostrate growing variety, tested 14.2% protein. Such oat grain would be ideal for
drought feeding, when no ‘green feed’ is available.
ORIGIN AND GENETICS OF OATS
The oat genome
All species of oats have originated in the northern hemisphere. The cultivation of oats is not
very old. Neither the Egyptians nor the early Europeans grew oats. De Candolle (1883)
ascribed a European origin to our cultivated oats, leaning on historical and philological facts.
The European group of Avena sativa were typical of north-western Europe. A large
Mediterranean group, sharply isolated from A. sativa, were A. sterilis and A. byzantina. These
three species belong to the hexaploid oats (2n = 42), and can be easily be crossed together or
with A. chinensis (2n = 42), the low yielding large naked oat from the Chinese centre of
origin.
These are our most important oats for breeding, testing and extension. “2n” represents the
number of chromosomes in the sex cells (gametes) after fertilization. The number of
chromosomes before fertilization is represented by n = 21. These chromosomes, however,
each consist of 3 basal groups of chromosomes, each of which has 7 chromosomes. By
dividing 7 into 42 we obtain 6, hence the term hexaploid. This represents the genome, the
complete complement of genetic material in a cell of this species. Here the genome is written
as AACCDD.
24. - 17 -
The weedy species of A. fatua, or black oats, also belongs to this group. North-western
Europe, including Wales, was also a centre for A. strigose and A. brevis, half weedy, part
cultivated diploid species (2n = 14), neither of which can be hybridised with A. sativa or A.
byzantina. These wild diploids were noted for resistance to smut, Ustilago avenae, crown
rust, Puccinia coronata, as well as mildew, Erysiphe graminis.
Vavilov found many varieties of A. sativa in Mongolia and northern China as well as in
Georgia and Armenia, together with A. fatua and A. ludoviciana (Vavilov 1920-1940). These
latter two were widely distributed all over south-western Asia. Vavilov found China to be the
centre for the large and naked-grain oats, A. chinensis, genetically related to the European
oats with chromosome numbers (2n = 42) and easily hybridising with each other. They were
first brought from China to Europe in the 5th
century AD (Breitschneider 1881). The Author
calls this A. chinensis to distinguish it from the small naked oat, A. nuda, which is a diploid
(2n = 14), like A. strigose and A. brevis. Most of the diploid species cannot cross with one
another, the exceptions being clauda x eriantha, wiestii x hirtula, wiestii x strigose, and hirtula
x strigose as listed in Table 1.4. Within the tetraploids, only the following crosses are
possible: barbata x vaviloviana, barbata x abyssinica, and vaviloviana x abyssinica. This
shows that possession of the same genomes, or sets of chromosomes, does not guarantee
interfertility within the diploid or tetraploid species.
Ethiopia, or the highlands of Abyssinia, is the centre of origin for A. abyssinica. Centre of
origin is a better term than Vavilov’s centre of type formation, which may have been
influenced by Darwin’s term, natural selection. In Table 1.4, the large naked oat created for
China, A. chinensis, is on the same line as the small naked oat, A. nuda. This is to show that
in the middle column for the tetraploids, a naked oat tetraploid has yet to be found.
Many investigators, as reviewed by Legget and Thomas (1995), thought that the cultivated
hexaploid oat had been derived by a simple trichotomy from a common progenitor. This was
found to be improbable. If all 3 groups came from a single basic species, the polyploid
species (the hexaploids) would have to be autopolyploids but they are not. Autopolyploids
are derived by the doubling of the constituent genomes, as by the conversion of AA, the
single genome, to AAAA. There is only one oat species like this, A. macrostachya, whose
genomic constitution is unclear (Legget and Thomas 1995). This is the only outbreeding and
perennial species of Avena and the only one that is autotetraploid. All other oat species are
allopolyploids. One fact is certain: the cultivated hexaploid oats did not evolve from any of
the known diploid or tetraploid species, because the donor of the DD genome is unknown.
The same is true for the hexaploid wheat genome, which also has an unknown donor.
The origin of the third or D genome of the hexaploid (2n = 42) species in cultivated oats
varieties is completely unknown. This makes Rajhathy and Thomas’ (1974) theory of oat
evolution purely speculative. The discovery of A. canariensis and the magna-murphyi
complex in the tetraploid group (2n = 28) of oats is said to realize Vavilov’s law of
homologous variation. This is said to be a structural analogy but this does not explain
anything. The missing D-genome has never been found in the diploid oat species, which have
AA or CC genomes, or in the tetraploid species which have AABB or AACC genomes. Our
cultivated hexaploid oats are designated by the AACCDD genome complex. Therefore, on
evidence, hexaploid oats cannot have originated from diploids or tetraploids, certainly not by
natural crossing, or ‘fusion of distinct genomes,” as postulated by Rajhathy and Thomas
(1974).
25. - 18 -
Table 1.4 Species of Avena genus, the 3 karyotypes and their genomesa
.
Diploid = 7 Genome Tetraploid n= 14 Genome Hexaploid n = 21 Genome
clauda CC barbata AABB fatua AACCDD
eriantha CC vaviloviana AABB sterilis:
ventricosa CC abyssinica AABB ludoviciana AACCDD
prostrata CC maroccano AACC maxima AACCDD
damascena AA murphyi AACC macrocarpa AACCDD
longiglumis AA sativa: hiemis AACCDD
canariensis AA orientalis AACCDD
wiestii AA diffusa AACCDD
hirtula AA bizantina:
strigose AA hiemis AACCDD
brevis AA verna AACCDD
nuda AA chinensis AACCDD
a
From Guerin (2003). Note that there is a large diagram on p.154 of the Author’s self-published book referred to here, showing all the crosses that are
possible within the Avena genus.
26. - 19 -
The explanation given is that the donor is either extinct or has evolved into a different species.
This depends entirely on the value of the hypothesis itself, that differentiation is a function of
time. The possibility that the genome donor may never have existed is not even stated, let
alone the alternative which that possibility would imply: separate origin of species in the
various Vavilovian centres. This applies both to oats and wheat, Triticum aestivum L., which
has a genome complex of AABBDD, in which the donor of the B-genome is unknown. Much
ingenious effort and thinking have gone into this work, but we have not yet exploited a
fraction of the cultivated oat gene pool.
The significance of multigenic traits
The history of the science of genetics has been a stormy one. The first of the great hybridisers
was Joseph Kölreuter, 1733-1806 (see glossary). He described over 500 experiments,
including Nicotiana rustica x N. paniculate, which gave a very vigorous hybrid, which was
sterile when self-fertilised. It was Gregor Mendel (1822-1884), the father of genetics, who
explained the continuous variation in height in Kölreuter’s second generation (F2) tobacco
plants after crossing a dwarf with a tall parent. This was the green light or impetus for
multigenic plant breeding for traits requiring quantitative or cumulative effects, as for high
yielding oats from the Author’s Isolection system.
Between 1900 (when Mendel’s paper was discovered) and 1910, most geneticists could see
Mendel’s work as showing only discontinuous variation, looking only at his pea crosses.
Mendel, however, had also discovered continuous variation, when he crossed white-flowered
and purple-red-flowered beans. This gave an intermediate flower colour (pink) in the F1
progeny and a continuous spread from white to purple-red in the second generation.
Geneticists then began to see that alleles (pairs of a gene) had small but cumulative effects
with semi-dominance rather than complete dominance, which were behaving in a Mendelian
fashion. This gave rise to the multiple-gene hypothesis. This is now one of the most
important principles of genetics (Gardner and Snustad, 1984). This principle has been greatly
strengthened by the use of statistical methods by R.A. Fisher in England. Fisher laid the
foundation for the analysis of variance and the beginnings of experimental design and success
in comparing oat variety yields in biometrically designed trials in Australia (Fisher 1925).
These trials proved to other plant breeders that yield differences were or were not significant.
The economically significant groups of oats
There are various classifications for oats. These include those based on grain morphology.
One can look at the grains after threshing or harvesting and see if the rachilla or stalk remains
with the primary grain (Avena sativa) or with the secondary grain (Avena byzantina).
Although the varieties Blackbutt and Carbeen derive from the same cross, the latter’s grain
articulation is typically A. byzantina, while that of Blackbutt is a 50-50 mixture suggesting its
own hybrid origin. Similarly Swan has the hybrid morphology of its sister-line, West. Swan
and West belong to the specialised grain oats and therefore another mark of identity is
required. The photograph of floret separation in Figure 2.11 of Chapter Two shows this.
The early habit of growth is, however, the best indicator of economic significance. The habit
of growth has a significant impact on the economic significance of oats and this is further
described under the latter sections in this book that address dual-purpose oat varieties. These
groups are prostrate and erect growing varieties and these are further sub-divided into
intermediate, semi-erect, erect and very erect (described below). The most reliable mark of
identity is whether the juvenile stage has a prostrate (Blackbutt and Carbeen), intermediate
(Cooba), semi-erect (Coolabah), erect (Avon, Cassia, Stout and Swan) or a very erect (Moore
27. - 20 -
and West) habit of growth. The prostrate varieties bury their growing point, tiller profusely,
resist frost and grazing damage and are therefore dual-purpose varieties, suitable for both for
both grazing and grain production. These two groups of oats, based on growth habit, have
been compared in South Australia (Craig and Potter, 1983). This trial was evenly grazed by
sheep, which also provided fertiliser and an even grazing. Comparing 0, 1 and 2 grazings, the
erect varieties yielded more grain after one grazing than after 0 or 2. The most prostrate
variety, Carbeen, was the only variety to yield more grain after 2 grazings than after 0 or 1
grazing in this trial. In this trial, plants were grazed by 100 sheep for 3 days to a uniform
height of 2.5 cm above ground level. The prostrate variety, Carbeen, significantly outyielded
all other varieties in grain recovery. The variety Carbeen, and the details of this trial, are
further described in Chapter Three.
The erect varieties from Western Australia have larger grains than the prostrate varieties from
the Glen Innes breeders, and are usually accepted for milling for this reason, and the fact that
they are grown in a drier finishing season, which does not discolour the grain. The Glen Innes
bred varieties are smaller grained but are higher in groat percentage than varieties bred at
Temora, Southern NSW, South Australia and Western Australia. Avena strigosa, cultivar
Saia, has very small grains which give it a high volumetric weight. Saia is crown rust
resistant and sown in Southern Queensland and Northern NSW coastal areas for cattle
grazing. The grains possess up to 20% protein but belong to the diploid species of Avena that
cannot be crossed (or only with great difficulties) with the normal cultivated hexaploid species
of oats.
GLOBAL AND ECONOMIC ASPECTS OF THE OAT CROP
Overview
Economic factors, and to some extent political factors, determine the motivation to grow a
particular crop or pasture. These factors encompass global agricultural land potential, world
population and comparative crop and pasture yields. Some of the data for this study has been
taken from the Food and Agriculture Organisation (FAO) of the United Nations annual reports
from 1948 to 1992. This data has been assembled and critically evaluated by Sassone (1994)
and further elaborated by the Author in the remainder of this chapter.
Oats, mainly Avena sativa and A. byzantina, have an important role in world pasture
production. Considerable research and developments have been conducted on this crop in
Australia and overseas. The application of research findings in agriculture has contributed to
overcoming world food shortages (Sassone, 1994). Such has been the impact of improved
practices in agriculture that countries in Asia, for example, are now demanding more milk
products and meat in the diet as compared with traditional foods, in particular, rice. United
Nations Yearbooks show that even with population increases of about 20%, the number of
telephones, refrigerators and other amenities in third world countries have approximately
doubled. Average real incomes have more than doubled (UNICEF, 1993).
This demand for milk and meat products now increases the need for more efficient means of
their production, including improved pastures and grain production. The role of dual-purpose
grain types, oats grown for both grazing and grain production, to assist these developing
countries to meet their demands in the Southern Hemisphere, including Australia, has been
identified as being important (Guerin, 1961; Guerin and Guerin, 1992). Oats is not a coarse
grain only, or a source of carbohydrate only such as wheat and rice (Whittemore and Elsley,
1976). Oats, however, possesses other characteristics which make it unique as a food source
28. - 21 -
for both humans and livestock and these have been described earlier in this chapter. Due to
favourable amino-acid ratios, oats have a higher biological value than barley, wheat or maize.
Along with the cholesterol lowering attributes of the grains, oats can be considered as “the
health crop”.
Global trends in population, food supplies and diets
Population growth or rate of increases is defined as the birth rate minus the death rate. As of
1990, this value for the world was 1.7%. Africa has the highest rate of increase in the world
at 3.0% (Table 1.5). Asia and Latin America also have the second and third fastest rates of
increase. The first world continents, Europe, North America and the former Soviet Union are
increasing at less than 1%. These latter regions have fertility rates below 2.2 children per
female, which represents the replacement or zero population rate. Sassone (1994) predicts
that world populations may begin to decrease by the year 2050.
Based on the FAO data, it is evident that world food production has increased, regardless of
world population growth. Over the period studied by Sassone (1994), food production,
especially rice and meat, quadrupled, while world population has little more than doubled. It
is apparent that farmers in the developing world have adopted many of the new technologies
and developments in agricultural science, which have dramatically improved crop yields.
Intense effort by agricultural extension practitioners in developing countries have improved
the rates of adoption of appropriate technologies for both grain and pasture production in
these countries. These adoptions have included improved understanding of the need for
fertilisers, pesticides, herbicides, soil tillage practices, and the growing of improved crop and
pasture varieties. In India for example, on average, the population consumes the 2,200 calories
recommended by the Food and Nutrition Board (Sassone, 1994). Developing countries in the
Far East increased grain production by 12% while in Africa, grain production increased by
47% (Sassone, 1994).
Meat production consistently increased from 1981 to 199 (Table 1.6). Total cereal tonnages,
including wheat and rice, declined in volume over the same period. An inference that can be
made from this data is that the area of land under pasture is likely to be increasing.
World grain prices fell after 1981, while stocks of grain rapidly increased (Sassoon 1994).
Supply controls were applied in most countries in the form of acreage reduction measures.
During 1981-85, difficulties stemmed from depressed agricultural exports, high interest rates,
and supply surpluses. In Australia this effect was particularly marked where meat production
increased 22% from 1984-91.
In the developed nations, farmers reduced grain production after 1984 because of massive
grain surpluses. Farmers of the Near East and of Africa, on the other hand, increased grain
production by over 40% between 1984 and 1991.
The expansion of land areas used for rice and meat production has broader implications for
integrating more balanced diets into the households of developing countries. Furthermore, the
increased area of land devoted to pastures reflects the potential of increased crop rotations and
ley farming and, therefore, general soil improvement.
29. - 22 -
Table 1.5 World population densitiesa
.
Location
Population (P x 106
)
1980
Population (P x 106
)
1990
Population Increase
(%)
Land Area
(km2
x 103
)
Population Densityb
(P/km2
)
World 4,448 5,292 1.7 136,255 39
Africa 477 642 3.0 30,305 22
Asia 2,583 3,171 1.9 27,582 115
Latin America 363 448 2.1 20,535 22
North America 252 278 0.8 21,962 13
Europe 484 498 0.2 4,933 101
Oceania 22.8 26.5 1.5 8,536 3
Former USSR 266 289 0.8 22,402 13
a
Sassoon (1994); b
P = Individual persons.
30. - 23 -
Table 1.6 Food production and population growtha
.
World Tonnes (x 106
)
Year
1948-52 1960 1970 1980 1990
Total cereals NAb
NA 1215 1566 1952
Wheat 155 222 318 446 597
Rice 111 158 316 399 518
Total meat production 40 60 107 133 175
Population (x106
) 2516 3020 3698 4448 5292
a
Sassoon (1994) from Food and Agriculture Organization of the UN annual reports; b
NA = not available.
31. - 24 -
Table 1.7 Changes in total grain yields and reduction in total crop growing areaa
.
Cropping Years
Cropping Area
(ha x 106
)
Total Grain Production
(x106
)
Yield
(t/ha)
1975/76 707.7 1236.8 1.75
1980/81 721.8 1427.2 1.98
1985/86 715.0 1645.6 2.30
1989/90 693.3 1665.8 2.40
1992/93 687.7 1758.5 2.56
a
From World Grain Situation and Outlook (USDA, 1993).
32. - 25 -
Table 1.8 Annual rate of change (%) of increase in production of farm productsa
.
World Tonnes (x 106
)
Produce
1981 1986 1990 1991 Change (%)
Total cereals 1646 1854 1971 1887 1.45
Wheat 454 535 601 553 1.97
Paddy rice 412 471 522 518 2.26
Total meat 138 157 176 179 2.87
a
Sassoon (1994).
33. - 26 -
International increases in cereal grain yields
World cereal grain yields have increased marginally in the period 1979 to 1994. The greatest
increase was observed with the wheat crop. The increases in barley and oat yields were lower
over the same period. While the total tonnage of wheat and barley have increased over this
time, world oat yields “appear” to have decreased slightly. However, the accuracy of
Australian oat yield statistics do not reflect actual yields because the oat crop is typically
grazed throughout the growing season prior to harvest and considerably less stringent
agronomic management is applied to this crop than to other cereals, in particular wheat and
barley (Simmons, 1987).
World grain production multiplied by 2.6 from 1950 to 1984 at the same time that the world
human population less than doubled. The price of grain decreased over the same period and
removed farmer’s incentives to grow more. In the 1950s and 1960s, a bushel of grain was
worth the equivalent in dollar value of a barrel of crude oil. In the 1970s and 1980s, the price
of grain in real terms was approximately 20% of the 1950 price, allowing for inflation, or 10%
of the price of a barrel of crude oil. Farmers in the developed world therefore reduced grain
production after 1984.
Total world grain yields increased substantially over the period of 1976 to 1993 from 1.75 to
2.56 t/ha (Table 1.7). Over the same period, the total area of land used for grain production
decreased from 7.08 x 108
ha to 6.88 x 108
ha. However, there was a temporary increase
during this period to 7.22 x 108
and 7.15 x108
during the years 1981/82 and 1985/86,
respectively.
As a result of this increased productivity in grain production, approximately 30x106
ha have
been made available for other agricultural activities including the growing of improved
pastures. This increased availability of land for pasture production has increased the potential
for dual-purpose grazing cereals, including oats. There is evidence that this has occurred from
the increase in total meat production worldwide (Tables 1.5 and 1.8). This total increase in
meat production, however, does not include increases due to the increased total number of lot-
fed livestock and other intensive livestock industries. World-wide, approximately 22% of the
land area has potential to be used for pasture. This does not include the 11% of arable land or
the 30% estimated to be utilised in forestry. India utilises 92% of its agricultural potential
without using the 18% of its total area that is devoted to forestry.
The arable area of Australia of 48 million ha includes 17 million ha of crops and 31 million ha
of sown pasture and grasses. Forestry includes 41 million ha of native forest, 1 million of
plantation forestry and 36.5 million ha of protected wilderness areas, national parks and
conservation areas (Table 1.9).
The greatest part of Australia’s agriculturally potential land area of 419 million ha is used for
grazing. In no other country or continent has livestock production dominated agriculture as in
Australia. Hence Australia has played a leading role in the development of pasture
improvement and development of dual-purpose oat varieties. Furthermore, Australia has a
large potential to improve its dual-purpose oat and hence livestock production.
34. - 27 -
Table 1.9 World land utilisationa
.
Region
Total Area
(T) (ha x 106
)
Agricultural Potential
(ha x 106
)
Arable Area
(ha x 106
) (% of T)
Pasture Potential
(ha x 106
)
Forestry Area
(ha x 106
) (% of T)
Unusable
e.g. Desert
(ha x 106
)
World 13,392 4,407 1,406 (11) 3,001 4,068 (30) 4,917
Africa 3,030 1,047 204 (7) 843 629 (21) 1,354
North America 2,241 627 253 (12) 374 815 (36) 799
South America 1,784 497 89 (5) 408 927 (52) 360
Asia 2,753 893 444 (16) 449 565 (21) 1,295
China 956 287 109 (11) 178 77 (8) 592
India 328 178 164 (50) 14 61 (18) 89
Indonesia 190 13 13 (7) 0 152 (80) 25
Japan 37 7 7 (19) 0 25 (68) 5
Europe 493 240 149 (30) 91 140 (28) 113
Holland 3.6 2.2 0.91 (25) 1.3 0.3 (8) 1.1
UK 24.4 19.4 7.4 (28) 12 1.9 (8) 3.1
Australia 768 467 48 (6) 419 77 (10) 224
a
Sassoon (1994).
35. - 28 -
While there is a link between oat crop yields and the length of the growing season, on a world
basis (Table 1.10) (Forsberg 1986), there also appears to be a link between high oat yields and
high population density, but a closer correlation exists between high oat yields and the
“nurturing” or constructive policies of the mixed economy (private and socialist enterprises)
of the European Union. The small-scale, isolated nature of agricultural production, relative to
urban industries in the European countries makes state aid essential. O'Brien (1929) showed
how Germany led the world in this respect, followed by Denmark and France. England was
indifferent to rural problems, due to her espousal of free trade (see glossary), except in
wartime when feverish efforts were made to increase crop yields.
Australia has inherited the same predilection for free trade with disastrous repercussions on
both agriculture and manufacturing industries. Cribb (1982) portrays in detail this state of
Australian agriculture. Free trade is stated to be an “optimal” policy for a small, open and
competitive economy. A small economy is defined as having negligible market power and
one that cannot influence the equilibrium prices in world markets by its trade policy.
Protection may create sheltered markets and monopolies with little incentive for producers to
be efficient (Parikh et al. 1988).
Fair trade, however, is necessary to protect farm families as is being done in the European
Union under the revamped Common Agricultural Policy. Countries will become more self-
supporting and trade-restrictive in the future, as free trade inflicts further economic damage on
countries like Australia.
Table 1.10 Oat yields, growing days, population density and agricultural policy.
Country Yields (t/ha)a
Growing daysa
People/km2 b
Policyc
Ireland
Netherlands
UK
Germany
France
USA
China
Soviet Union
Australia
Spain
4.68
4.52
4.31
3.44
3.32
1.88
1.78
1.28
1.18
1.01
142
155
165
140
150
93
n.a.d
n.a.d
200-340
n.a.d
49
421
229
220
99
24
105
12
2
75
Nurturing
Nurturing
Nurturing
Nurturing
Nurturing
Nurturing
Socialist
Socialist
Capitalist
Capitalist
a
1983 data from Forsberg (1985); b
Russell and Coupe (1987); c
O'Brien (1929) for
background; d
not available.
36. - 29 -
Advantages of grazing the oat crop
Craig and Potter (1983), however, point out advantages of grazing the oat crop: (A)
Stimulating tillering and increased number of grain producing lateral shoots; (B) Reducing the
incidence of fungal diseases common in ungrazed crops; and (C) Reduction in lodging by
promoting stronger shoots and removing excess leaf area. Craig and Potter (1983) also found
that nearby annual pasture carried 8 ewes/ha giving 1450 kg/ha and 1830 kg/ha feed in early
August and early September respectively.
Another advantage of oats was the ‘saved pasture’ on which Crofts (1966) carried 7.4 ewes/ha
at Orange, NSW. This was twice the rate of grazed ryegrass-clover pastures yielding 4.5 kg
dry matter/ha/day and only one-fourth that of heavily seeded oats given N fertiliser (Table
1.11).
Table 1.11 Stocking capacity of oats compared with other pasturesa
.
Dry Matter Yields
Treatment
kg/ha kg/ha/day
Stocking Rate
(ewes/ha)
Ryegrass-clover (A) 448 4.5 3.7
Saved Pasture (B) 840 8.4 7.4
Oats @ 90kg/ha seeding rate (C) 1680 16.8 14.8
Oats @ 179kg/ha seeding rate + 67
kg/ha N (D)
3360 33.6 29.6
Ratio of D:A Treatments 7.5:1 7.5:1 8:1
a
From the trial conducted in Orange and reported by Crofts (1966). Records for a 100 day
winter (late May to August).
Clover-grass pastures grow abundantly in early summer but very slowly in winter in
comparison with winter or dual-purpose oats. Oats grow 4 to 8 times as rapidly as pasture
(Crofts, 1966) during the 100-day winter at Orange NSW, Australia. This result was achieved
with the old variety, Algerian, which gave at Richmond NSW, in a separate trial, less than
one-seventh the July yield of the High-vigour oat Blackbutt. Therefore oats and pasture are
both necessary for good livestock husbandry.
To further demonstrate the significance of the oat crop for grazing, even without N fertiliser
added, oats gave 4 times the stocking rate given by ryegrass-clover pastures and the dry
matter recorded 18% crude protein (Crofts 1966). Crofts (1966) also found that oats should
be planted when the mean daily temperature approaches 18°C (or 65 Fahrenheit), which at
Orange is about early March, and early April for lower elevations locations. By shutting up
large areas of oats in early September, soon after grazing, Crofts (1966) in no time could still
recover one tonne of grain per ha.
Although drier winters are better for pasturing sheep and cattle on an annual pasture like oats,
there is considerable potential untapped in the southern areas of NSW. In the winter rainfall
zone at Orange, NSW, Crofts (1966) obtained a remarkable response with Algerian (liable to
frost damage in the severe winters in New England), and to heavy rates of seeding and
37. - 30 -
nitrogen in 1962 and 1963. Algerian produced 3.4 tonnes per ha, 7.5 times the yield of
improved pastures and carried 29.6 sheep per ha, 8 times as many ewes as the clover-ryegrass
pasture during the 100-day winter period and carried 30 ewes per ha. The extra yield from
nitrogen was less expensive than quality pasture hay. By excluding sheep from the crop from
early September onwards, the 1 tonne per ha grain recovery obtained could be sold to offset
total costs, including 179kg of seed and 67kg elemental nitrogen per ha. Alternatively, the
grain could be kept as a drought reserve (Crofts 1966). Algerian, however, could not produce
such yields in a year like 1961 on the New England Tablelands, due to frost damage.
Forsberg and Reeves (1995) found that oats, next to rye (Secale cereale L.) are the most
versatile of the cereals regarding suitable soil type. Maximum oat yields require soil pH of
5.3-5.7 but can tolerate acid soils with a soil pH of 4.5. Nutrient (NPK) needs for oats are less
than those for wheat (Triticum spp.) or corn (Zea mays L) and can be tailored to the desired
yield level.
Oat production statistics and limitations to their interpretation
Overcoming the limitations of statistics is critical in maximising the productivity of the oat
crop. Government or industry compiled statistics typically have little value in guiding the
direction of research or funding of oat breeding programs. It is more profitable to study a few
statistically designed, well-managed and executed yield trials, as described in the latter
chapters of this book.
The world statistics (Table 1.10) given do not record the 1-2 tonnes of herbage dry matter
produced on many farms during the long growing season such as in NSW, Australia. This is
not recorded in the state and national yield statistics. This claim is supported by Mengersen
(1963) who at that time, estimated that at least 70% of the NSW oat crop is used for dual-
purposes production, that is, one or more grazings and then grain recovery. This is a very
important aspect of oat production that unfortunately is not reflected in state and national
yield statistics.
Other examples include the reported statistical oat yields in Ireland. Ireland, although
possessing the world's highest average yield, result from late spring sowings and could be
boosted further by winter or dual-purpose oats that utilise a longer growing season. The same
applies to China as well as to NSW, where late sowings result in low yielding crops that are
far behind actual Government research findings in NSW, as recorded here. Oat yields at
Cowra, NSW, have been higher than any values reported in world statistics. The research
plots at Cowra were not irrigated and yet out-yielded the irrigated trial at Coleambally. At
Richmond on the eastern coast of NSW, a dual-purpose oat line, P4315, produced over 10
tonnes of biomass per ha in a dry season (50% of the normal rainfall) without irrigation.
Other examples are described in the following chapters.
Statistics on oat production in NSW have been documented for many years. These figures
give little indication of oat yield potential, however, are of minor value only because they do
not always report which varieties were sown, soil types, sowing dates or if the crop was
grazed and for how long. This has been the case at least in NSW. NSW oat production
statistics, which are composite data compiled by the NSW Government, and grouped from all
regions of the state, are criticised because of their failure to show the differences between the
summer rainfall northern zone and the winter rainfall southern zone. Furthermore, such oat
production statistics do not reflect the total biomass yield or the total value that the oat crop
contributes to farming systems. The application of these statistics has led to a frost susceptible
38. - 31 -
oat variety being used for pasture research at Armidale (1977), after the frost resistant
Blackbutt had already been released to farmers in 1975. Shortcomings in government statistics
result in poor funding of oat research. Political economy, sociology and lack of knowledge of
agronomy and the value of oats for human and livestock nutrition, are also inhibiting the
further exploitation of the oat crop. Figure 1.1 shows cereal production statistics since 1981.
In 1990, only Scone and Windouran (both in NSW) showed higher yields for oats than for
wheat and barley (Fitzsimmons, 1990). Before 1982, even in 8 irrigation Shires, wheat and
barley outyielded oats in production of grain. Beginning in 1982 at Leeton, NSW, oats yields
started to rise above those of wheat and barley (Table 4.1, Chapter Four). During the previous
52 years from 1930 to 1982, the wheat and barley yields were always higher than those of
oats, and barley was the highest yielder until 1960. From 1960 onwards, wheat took over as
the highest yielder of the three cereals and continued so into the 1983 - 1990 period. Shires in
NSW in which oat grain yields are superior to those of wheat grain are those in which
irrigation is available. In these areas excessive grazing is physically impossible and less
likely than the production of crops for grain and this is described in detail in Chapter Four.
The Australian statistics (Cribb 1991) are also misleading because oats yield higher than
wheat and barley in the medium to higher rainfall zones (>500 mm) and oat breeders have
been forced to create early maturing lines like Cooba and Coolabah to be harvestable even
earlier than the early wheats.
There are other limitations to the value of oat and cereal grain yield statistics. Even when the
Bureau of Statistics gives the areas of oats that are grazed, it is important to know the name
and characteristics of the actual variety of oats that was grown. In many cases specialised
grain varieties, usually from Western Australia, have been grazed in the colder, drier winters
of NSW and because of their frost and grazing susceptibility have not recovered much, if any,
grain.
The comparative statistical cereal yield data presented in Figure 2.1 may suggest that a shorter
season variety like Cooba or Coolabah is invariably chosen to avoid a clash with wheat
harvest, with the result being a reduced yield. This is counter intuitive because in a wet
harvest period, wheat takes much longer to dry out than oats, and in a very short time after
rain, the oats can be harvested. This enables better use of expensive harvesting equipment
during the harvest season, even if grain storage facilities have to be increased, or organised
more efficiently. Longer season cultivars can be safely harvested in the higher rainfall wheat
areas, using Glen Innes to breed rust resistance.
Another important factor in statistics is the length of the growing season, which can vary from
year to year, and the response of the oat variety. This can be broken down in to the following
traits: (A) the length of the vegetative period of the variety, (B) its response to frost or
vernalisation, and (C) how rapidly it can flower and set grain after the last day of grazing.
The “statistical” Australian oat yield is a fraction of the actual yield, due to the grazing
tonnage not being recorded. As a result, oat research receives only a fraction of the funds due
to it in Australia where every other crop is funded on the basis of its total tonnage delivered to
a government agency or entering commercial channels. In turn, Australian farmers are denied
the benefits of more thorough and long-term research and plant breeding in oats.
Appendix A contains further statistical data on oat yields in Australia.
39. - 32 -
Figure 1.1 Statistical yields of the major cereals grown in NSW.
Extension of research to oat growers
With so much research and extension of information to farmers on other cash crops, relatively
little advice appears to be extended to the farmer’s oat crop, which experiences more
environmental stress than any other because of its versatility.
While plant breeders in the winter rainfall areas of Australia have produced dual-purpose oats
with particular emphasis on grain yields, with at least 70% of the total area sown to oats
during the 1960s was for dual-purpose grain and grazing (Mengersen, 1963), there is a gap
between oat breeding research, which has created new dual-purpose varieties, and farm
practice. This is due to a lack of knowledge and skill relative to the oat crop for a particular
location, soil and climate.
A similar lack of skill in wheat growing would result in uneconomic yields of wheat.
Prevention of Ophiobolus attacks on wheat requires that wheat should follow a crop of early
sown, well-grazed oats, to kill susceptible grasses that spread Take-all disease (Lazenby and
Matheson 1975). Heavy grazing of oats in cool winters will also destroy black oats (A. fatua
and others).
It is anticipated that the research presented throughout this book on the value of the oat crop
to famers will help fill the gap between scientific research into the further development of oats
as a pasture and grain crop and farming practice.
1
1.25
1.5
1.75
2
1981 1984 1987 1990
Year
Yield(t/ha)
wheat barley oats
40. - 33 -
CONCLUSIONS
There is now ample evidence to demonstrate that oats play an important role in human and
livestock nutrition. Oats provides grain for humans and livestock, a grazing or forage crop for
livestock, and the health benefits of oats are predominantly the cardiovascular disease
prevention properties of oats (through the cholesterol lowering effects of β-glucan) and the
glycemic effects of oats which is to reduce the increase in human blood glucose levels.
While the significance of the oat grain in benefiting human health has received considerable
attention, however, relatively little attention has been given to the important attribute of
combined grazing, grain production and total crop value in global agriculture. The oat crop,
because of its potential for grain recovery after grazing, has a sigficant role to play increasing
global pasture production. Particular oat groups, specifically those with prostrate growth
habit, have the required attributes for inclusion in breeding programs to develop suitable oat
varieties for dual-purpose capability and therefore for increasing pasture production.
The application of oat statistics by government agencies is holding back the attainment of
higher oat yields in Australia. Governments should review how oat production statistics are
used and recognise that these typically underestimate the overall value of the oat crop in
achieving sustainable farming systems.
41. - 34 -
REFERENCES
Archer, K.A. and F.G. Swain. 1977. Evaluation of oat forage for finishing prime lambs on the
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