biology of economic agriculture

1. RICE
Oryza sativa L.

2. Rice (Oryza sativa L.)
￭the most important staple food for a large
part of the world's human population:
 East Asia
 South Asia
 Southeast Asia
 Middle East
 Latin America, and
 West Indies
￭the grain with the second highest worldwide
production, after maize.

3. Expansion of rice cultivation
Asian Rice
Oryza sativa Wild Rice

4. Rice-Producing Countries

5. Rice Production and Consumption

6. Rice-Producing Countries
Together, China and India accounted for over half of the
world’s rice supply in 2006.
1. China: 182 million tons (28.8%)
2. India: 136.5 million tons (21.6%)
3. Indonesia: 54.4 million tons (8.6%)
4. Bangladesh: 43.7 million tons (6.9%)
5. Vietnam: 35.8 million tons (5.7%)
6. Thailand: 29.3 million tons (4.6%)
7. Myanamar: 25.2 million tons (4%)
8. Philippines: 15.3 million tons (2.4%)
9. Brazil: 11.5 million tons (1.8%)
10. Japan: 10.7 million tons (1.7%).
http://internationaltradecommodities.suite101.com/article.cfm/top_rice_producing_countries#ixzz0snCNSXzS

7. Taxonomy
Kingdom: Plantae (Plants)
Subkingdom: Tracheobionta (Vascular plants)
Superdivision: Spermatophyta (Seed plants)
Division: Magnoliophyta (Flowering plants)
Class: Liliopsida (Monocotyledons)
Subclass: Commelinidae
Order: Cyperales
Family: Poaceae (Grass family)
Genus: Oryza L. (rice)
Species: Oryza sativa L. (rice)

8. History
￭Rice is the world's largest food crop,
providing the caloric needs of millions
of people daily
￭There are two distinct types of
domesticated rice
 Oryza sativa, or Asian rice and
 Oryza glaberrima, African rice.

9. History
￭The genus Oryza contains 21 wild
relatives
￭The genus is divided into four species:
 O. sativa,
 O. officialis,
 O. ridelyi
 O. granulata species complexes
￭All members of the Oryza genus have n
= 12 chromosomes

10. History
￭O. sativa complex contains 2
domesticated species:
 O. sativa
 O. glaberrima,, and 5 or 6 wild species:
 O. rujipogon,
 O. nivara (also considered to be an ecotype
of O. rujipogon),
 O. barthii,
 O. longistaminata,
 O. meridionalis and
 O. glumaepatula, all of which are diploids.

11. History
 Oryza sativa: Asia
 O. glaberrima: West Africa.
 Oryza rujipogon: Asia and Oceania.
 O. barthii and O. longistaminata: African
 O. barthii:endemic in West Africa
 O. longistaminata: throughout Africa.
 Oryza meridionalis: native to Australia
 O. glumaepatula: endemic in Central and
South America.

12. History
￭Many phenotypic differences are
obvious between O. sativa and its wild
relatives
￭Wild rices typically display long awns
and severe shattering for seed
dispersal, whereas the domesticated
type have short awns if any and
reduced shattering to maximize the
number of seeds that can be harvested.

13. Botany

14. Germinating seed
The coleorhiza protrudes first Radicle or primary root breaks
through the covering
Coleoptile emerging as a
tapered cylinder

15. Seedling
Mesocotyl pushing the coleoptile
above the soil surface
First and second seedling leaf

16. Tiller
Types of roots Secondary adventitious roots

17. Culm
Young and mature culm

18. Tillers

19. Leaf
Leaves
alternate on
the culm in
opposite
directions

20. Leaf
Sheath pulvinus Leaf collar Ligule and auricle
Parallel veins on upper surface Leaf midrib
Rice and grassy weed comparison
Different varieties with varying blade characteristics

21. Panicle and Spikelet
Rice panicle

22. Panicle and Spikelet

23. Floret

24. Flower

25. Rice grain
Rice grains Rice hulls

26. WHAT IS ORGANIC RICE?

27. Organic Rice
￭Free from chemical
￭fat free and high carbohydrate content
￭red and brown rice have higher fiber
value than white rice
￭has low sugar content
￭When you eat 45 grams of organic rice,
you only consume 160 calories of
carbohydrates.

28. Organic Rice production
￭avoid the use of synthetic fertilizers,
pesticides, and growth regulators
￭Instead they rely on crop rotations
￭biological pest control
￭maintain soil health
￭supply plant nutrients
￭minimize insects, weeds, and other
pests.

29. Weed Suppression
￭Weed control and soil fertility are the
principal challenges
￭primary weed-control practices include
 crop rotations
 land leveling
 seedbed preparation
￭water management
￭rotary hoeing.

30. Soil Fertility
￭Maintaining soil fertility in organic
cropping typically involves some
combination of crop rotation with
deep-rooted legume crops or green
manure/cover crops
￭applying
 animal manures
 composts
 other approved organic amendments.

31. Soil Fertility
￭Nitrogen is usually provided through
the growing of legume cover crops
￭Bone meal is a good source of cheap
phosphorus (content of around 12%)
￭Rice straw and manure are good
sources of potassium.

32. Organic manure
￭Organic manures obtained either from
cattle or plants
￭Organic manure's – maintains better
structure of soil
￭Green leaf manure
 mainly neem, Pongamia pinnata and
Glyricidia
￭Green manure
 daincha, manila agathi, sunhemp.

33. Insects and diseases management
￭Rice is grown in flooded fields, insect
pests are usually a minor problem
￭Fall armyworm and chinchbug are
easily controlled by a flush of water
￭Timely planting, variety selection, and
cultural practices to suppress
 weeds control
 stinkbugs and
 water weevils.

34. Biofertilizers for rice cultivation
￭Bio-fertilizer are eco friendly and are
environmentally safe
￭The biofertilizers used for rice crop
 Azospirillum
 Phosphobacteria
 Blue green algae Azolla
 Mycorhiza.

35. Application of biofertilizers
￭Azospirillum: is a symbiotic bacteria and
it is an important biofertilizers used in
rice
￭Azospirillum treatment is
recommended for seed, seedlings and
in main field
￭Seed treatment: 600 g/ha of
Azospirillum culture are to be mixed
with water where the seeds are soaked
one night before sowing in the nursery
bed.

36. Application of biofertilizers
￭Main field: 2000 g/ha of Azospirillum
with 25 kg farmyard mamure and 25 kg
of soil are mixed uniformly and
broadcasted in the main field before
transplanting
￭Seedling treatment: A slurry can be
prepared by mixing Azospirillum at
1000 g/ha in 40 litres of water and root
portion of transplanted rice seedlings
are dipped in bacterial suspension for
15-30 minutes.

37. Uses
￭Azospirillum bacteria thrives in root zones of
rice and is capable of fixing more atmospheric
nitrogen which is absorbed by the plants
￭Azospirillum also solubilizes phosphorus and
silicon to some extent required by rice
￭It renders plant drought tolerant when
irrigation or rainfall is delayed
￭By adopting Azospirillum application 30 per
cent of the inorganic nitrogen usage can be
reduced.

38. Blue Green Algae (BGA)
 Blue Green Algae (BGA) is another
type of biofertilizer used as an alga
form. Important species are
Cyanobacteria, Anabaena, Nostoc
and Tolypothrix
 Blue green algal occurs naturally
and comes up well under moist
conditions. This can also be
artificially cultured.

39. Uses
￭The nitrogen fixed by BGA is about 15
kg/ha over a season
￭It oxygenates the water impounded in
the field
￭It excretes organic acids that renders
phosphorus solubilisation
￭The algal mat in paddy fields also
protects loss of moisture from the soil.

40. Azolla
 Azolla is a water fern having an algal
symbiont Anabaena azolla fixing
atmospheric nitrogen
 Azolla can be multiplied by
constructing nurseries with 10 cm
deep standing water and adding
superhphosphate at 8 kg P2O5/ha in
small plots
 It can be applied as green manure
prior to rice planting

41. Uses
￭Azolla excretes organic nitrogen in water
during its growth and also immediately upon
trampling
￭Fern fronds are soft and rapidly decomposed.
￭It absorbs traces of potassium from irrigation
water
￭Azolla provides nitrogen, potassium organic
carbon etc.
￭It prevents weed growth in rice field water.

42. Phosphobacteria
￭This type of biofertilizers solubilise
phosphates in the soil and render them
in available form for crop plants
￭This is applied as the same dose in
same manner as Azospirillum.

43. Uses
￭25 to 50 of the recommended
Phosphorus can be reduced depending
upon the native phosphorus content of
the soil.

44. Mycorrhiza
￭It occurs naturally in low land and
upland rice. It mobilizes the
phosphorus required by rice
￭Since, biofertilizers are ecofriendly
inputs and are safer to the
environment, farmers can adopt them
and get benefited.

45. WHAT IS HYBRID RICE?

46. Hybrid Rice
￭Hybrids are produced by crossing two
inbred - genetically fixed - varieties of a
particular crop
￭Hybrids are special because they
express what is called "heterosis" or
hybrid vigour
￭The idea is that if you cross two parents
which are genetically distant from each
other, the offspring will be "superior",
particularly in terms of yield.

47. Heterosis (hybrid vigor)
￭application to increase:
 productivity (yield/unit/time, 15-20% of
yield advantage), and
 economic returns
￭Heterosis
 A universal phenomenon that F1
generation shows superiority to both
parents in agronomic traits or yield
 has been exploited commercially in many
agricultural crops.

48. Normal Rice Spikelet
(self pollinated crop)
Sterile Rice Spikelet
(Male Sterility)
Hybrid Seed Production
(Male Sterile x Normal Rice)
How Hybrid Rice?

49. Male Sterility Systems in Rice
￭Male sterility: a condition in which the
pollen grain is unviable or cannot
germinate and fertilize normally to set
seeds
￭Male Sterility Systems (genetic and
non-genetic):
 Cytoplasmic genetic male sterility (CMS)
 Male sterility is controlled by the
interaction of a genetic factor (S) present
in the cytoplasm and nuclear gene (s).

50. Male Sterility Systems in Rice
 Environment-sensitive genic male sterility
(EGMS)
 Male sterility system is controlled by
nuclear gene expression, which is
influenced by environmental factors such
as
 temperature (TGMS)
 daylength (PGMS), or
 both (TPGMS).
 Chemically induced male sterility
 Male sterility is induced by some chemicals
(gametocides)

51. Release of IRRI Hybrids in Different Countries (1994-2005)
IRRI Hybrid Released as Country Year released
IR64610H MGR-1 India 1994
IR64611H KRH-1 India 1994
IR64616H Magat Philippines 1994
IR65489H DRRH-1 India 1996
IR68284H Mestizo 1 Philippines 1997
IR69690H Sahyadri India 1998
IR69690H HYT-57 Vietnam 1999
IR69690H BRRI Dhan Hybrid 1 Bangladesh 2001
IR69690H Rokan Indonesia 2002
IR75207H Mestizo 2 Philippines 2002
IR75217H Mestizo 3 Philippines 2002
IR78386H Mestizo 7 Philippines 2005

52. “Super high-yielding” hybrid rice breeding in China
Progress of "Super High-Yielding" Hybrid Rice Program in China
Goal (single-season) Progress (2006)
Stage Yield (t/ha) Years Breeding Commercialization
Start 8.25 1997
Phase I 10.5 1996 - 2000 Finished Large area extension
Phase II 12.0 2000 - 2005 Finished Started
Phase III 13.5 2005 - 2010 Started

53. Hybrid Rice

54. Hybrid Rice Seed Production
In Asia In United Sates

55. WHAT IS GOLDEN RICE?

56. Chronic Undernutrition among Children
Percentage of
stunted children

57. Estimated Annual Number of Child Deaths
Precipitated by Vitamin A Deficiency (Asia)
600 8,000
30,500
14,000
2,000 300
13,000 6,900
56,000
4,500 1,400 2,000
28,000
330,000
350000
300000
250000
200000
150000
100000
50000
0
Bhutan
Cambodia
Bangladesh
China
India
Indonesia
Myanmar
Lao PDR
Mongolia
Philippines
Nepal
Pakistan
Thailand
Viet Nam
Estimated Annual Number

58. VAD in China – current situation
￭The deaths of over 20,000 children each
year from increased susceptibility to
infection.
 Cause: vitamin A deficiency
￭Approximately 12% of China's children
growing up with lowered immunity, leading
to frequent ill health and poor growth.
 Cause: vitamin A deficiency (the prevalence
of vitamin A deficiency in children under 6 is
estimated at 12%).
Vitamin & Mineral Deficiency: A damage assessment report for China.
Micronutrient Initiative and UNICEF 2004

59. Trends in the Prevalence of Vitamin A
Deficiency
(by Age, and by Physiological State:
1993 & 1998)
35.3
Philippine Nutrition: Facts and Figures
(National Nutrition Survey, 1998)
16.4 16.4
38.0
22.2
16.5
50.0
40.0
30.0
20.0
10.0
0.0
Children Pregnant Women Lactating Women
Percent Prevalence
1993 1998

60. What Is Golden Rice?
￭is created through recombinant
technology, genetically engineering the
rice to produce β-carotene
￭by introducing 4 extra genes for the
respective enzymes into the
endosperm
￭The enzymes are required to complete
the biosynthetic pathway in order for
the rice to synthesize and accumulate
β-carotene or pro-vitamin A.

61. What Is Golden Rice?
￭The genes are isolated from Narcissus
pseudonarcissus (daffodil)
￭Theses genes code for the enzymes:
 phytoene synthase (psy)
 phytoene desaturase and
 lycopene β-cyclase.
￭The bacterial enzyme carotene
desaturase is utilized to simplify the
transformation process.

62. Basic Carotenoid Biosynthetic Pathway
IPP DMAPP
GGPP (C20)
Phytoene (C40)
desaturation
Lycopene (C40)
cyclization
Carotenes
Phytoene synthase
Plant source
Phytoene desaturase
Bacterial source
a - carotene b - carotene
b-cryptoxanthin
zeaxanthin
canthaxanthin
astaxanthin
Xanthophylls
a-cryptoxanthin
lutein
(Lycopene cyclase)
Bacterial source

65. ANY QUESTIONS?

66. THANK YOU