1. Prague
14th June 2011
Field experience with RR maize
in Czech Republic
Josef Soukup
V. Venclová, M. Jursík, J. Holec, J. Janků, L. Procházka
Czech University of Life Sciences Prague
soukup@af.czu.cz

2. Content of the presentation:
Maize in CZ
Environmental conditions and weed
occurence in CZ
Principles and issues of weed control
in maize
Experience with Roundup Ready
system in maize
Field visit - trial with RR maize

3. Corn production: 2/3 of the area or 8.4 Mha
Silage: 36% of the area or 4.7 Mha
Source: European Confederation of Maize Production

4. Biogas stations
http://www.biogaz-zeneris.com.pl/attachments/079_Ready_Biogas_Stations.pdf

5. Map of biogass stations in CZ
(253 in total)

6. Area in CZ endangered
by water erosion

7. Water erosion
most endangered
strongly endangered
moderat. endangered
slightly endangered
not endangered
(www.vumop.cz)

8. „Cross Compliance“ requirements
GAEC – Good Agricultural and Env. Conditions
GAEC 1, GAEC 2 – Soil erosion
Maize and other wide-row crops may not
be grown in fields strongly endangered by
erosion
In field moderately endangered by erosion,
only soil conservation tillage may be used
Plant residues should cover 30% of soil surface
No-till or reduced tillage should be used

9. Mulch as a protective measure
against water erosion

10. Maize sowing in mulch
using no-till sowing machine

11. Weed control in maize
dependes on site conditions
Geographical distribution of weeds
Mediterranean, Central/West/North Europe
Climatic / weather conditions
evaporation, drought periodes
soil moisture – weed emergence, herbicide uptake
Farming practices
share of maize in crop rotations
soil tillage systems

12. Natural conditions vs. Lowland, warmer regions
weed occurence in CZ Amaranthus retroflexus
Echinochloa crus-galli
Polygonum lapathifolium
Agropyron repens
Chenopodium album
Polygonum convolvulus
Higher altitudes, colder climate Abutilon Theophrasti
Chenopodium album ...
Agropyron repens
Polygonum lapathifolium
Polygonum convolvulus
Polygonum aviculare
Matricaria sp. oceanic continental climate
...

13. Most frequent weeds in CZ
(conventional: after herbicide application)
conventional farming
Survey by Kolarova and Tyser, 2008-2009

14. Most frequent weeds in CZ
(organic: after mechanical weed control)
organic farming
Survey by Kolarova and Tyser, 2008-2009

15. Weeds of various life cycles
can occur in maize...
Summer annuals
(Chenopodium album, Polygonum lapathifolium,
Amaranthus spp., Echinochloa crus-galli, Solanum
sp., Mercurialis annua, Abutilon, Panicum, ...)
Winter annuals
(Matricaria spp., Stellaria media, Galium aparine,
Thlaspi arvense, Capsella bursa pastoris, ...)
Spring annuals
(Polygonum convolvulus, P. aviculare, Geleopsis
tetrahit, Sinapis arvensis, Avena fatua, ...)
Perennial
(Agropyron repens, Cirsium arvense, Concolvulus
arvensis, Sonchus arvensis, Equisetum arvense,...)

16. Emergence of summer annual weeds (CZ)
450,0
Driving factors:
400,0
- temperatures
A. retroflexus - soil moisture
350,0
p o č e No. of emerged tlin (m 2 )
- seed dormancy
t v ze š lý c h ro s plants
300,0 - photoperiodism
250,0
- soil tillage
E. crus-galli - ...
200,0
Ch. album
150,0
S. nigrum
M. annua
100,0
50,0
D. stramonium
0,0
3
4
5
6
7
.7
.8
.9
0
1
3.
2.
2.
1.
1.
.1
.1
31
30
29
29
28
3-4 months weed emergence
Jursík et al. 2007, adapted

17. Patterns of weed emergence in maize:
- many factors involved
- cumulative temperatures seem to be the
main factor
- soil moisture and photosensitivity are the
sources of seasonal variability
- very hard to predict the best time for weed
control in maize
Sousa et al.: Predicting weed emergence in maize crops under two contrasting climatic
conditions. Weed Res. 3, 251-260, 2009.

18. Influence of temperature
on crop – weed interactions
Temperature influences:
• weed community composition
• symetry of competition
• photosynthesis and biomass accumulation

19. Impact of soil mosture
Eveness of weed emergence
Efficacy of soil active herbicides

20. Daily precipitations before
the application of PRE herbicides
(May 1st - May 15th, 2010)
rainfall period application 12.5.2010
sowing date 12.5. 2010

21. 2010 – plots after pre-emergence
application of acetochlor + terbuthylazine
tillage with plough no till - mulch
good effect of pre-emergence herbicides in 2010

22. Daily precipitations before
the application of PRE herbicides
(April 15th - May 15th, 2011)
application date 28.4.
dry period
sowing date 28.4.2011

23. 2011 – plots after pre-emergence
application of acetochlor + terbuthylazine
tillage with plough reduced tillage
failure of pre-emergence herbicides in 2011

24. Weed competition in maize
(yield reduction ~ 30-70%)
untreated plot

25. Critical period in maize-weeds competition
„period for exclusion of weed competition“
relative yield [%]
100
weeds occurr until ...
80 weeds occurr from ...
60
4 . – 8. maize leaves
40
20
critical period
0
time scale (maize growth stage)

26. Most popular herbicides in CZ
Pre-emergence
acetochlor + terbuthyazine
terbuthyazine + S-metolachlor
isoxaflutole

27. Increasing requirements
on safety of plant protection products...
Result of Review Programme
of existing pesticides, 2001-2009
Regulation 1107/2009 EC on placing on the market of plant
protection products 2009/128
Directive 2009/128 EC on the sustainable use of pesticides

28. Most popular herbicides in CZ
Post-emergence
terbuthylazine + S-metolachlor
nicosulfuron
rimsulfuron + dicamba
foramsulfuron + iodosulfuron
mesotrione, tembotrione
terbuthyazine + S-metolachlor +
mesotrione
isoxaflutole + thiencarbazone

29. Do we need Roundup Ready?
RR allows application flexibility according
weed pressure – important premise of IWM,
eliminates crop injuries (phytotoxicity),
provides efficient and cheap solutions against
grasses – both annual and perennial,
enriches number of herbicide modes of action
used in maize,
exhibits a very good environmental profile.

30. RR - no problem with crop injury
2,4 D
Slight crop injury (phytotoxicity)
5-15% is very common for many
post-emergence herbicides
bromoxynil
rimsulfuron

31. Use of herbicides in conservation tillage
(no-till, mulch)
Roundup Ready Conventional pre-em

32. Five years experince with
Roundup Ready technology in maize
3 years small plot experiments (2007-2009)
sensitivity of individual weed species
impact on composition of weed community
efficacy and selectivity of various herbicide
treatmens in RR system
2 years large plot experiment (2010-2011)
efficacy of various herbicide treatments
performance of RR in various soil tillage systems
impact of technology on NTOs

33. Differences in sensitivity
to glyphosate in different weed species
Amaranthus retroflexus Echinochloa crus-galli
100 100
1 1
80 80
60 60
response
response
40 40
20 20
0 0
0 0.1 1 10 100 1000
0 0.1 1 10 100 1000
dose
dose

34. Different species sensitivity (WAT4)
Weed Picture Curv ED50 ED90 ED90 / ED50
ratio
AMARE 197.1 411.9 2.1
AMARE
SOLPS 265.4 475.0 1.8
CHEAL 363.6 677.1 1.9
MERAN 249.1 685.4 2.8
ECHCG
ECHCG 361.7 1334.6 3.7

35. Summary – species sensitivity
to glyphosate
High differences in sensitivity to glyphosate between
tested species were found
AMARE, SOLPS – very sensitive (ED90 ≅ 400 - 500 g ha-1)
CHEAL, MERAN – medium sens. (ED90 ≅ 700 g ha-1)
ECHCG, POLLA – low sensitivity (ED90 ≅ 1300 g ha-1)
Regeneration occured when ED90 / ED50 > 2.8
(in ECHCG, MERAN)
Intended registered rate (2+2 or 3+3 lt/ha) of Roundup
is sufficient for control of all tested annual species
The herbicide dose should be chosen according the
most tolerant species to avoid the weed shift

36. Large-plot field trial
3 soil tillage systems
plough + conventional seedbed preparation
reduced tillage in autumn + conv. seedbed
reduced tillage in autumn + seeding in mulch
5 herbicide treatments
pre-emergence: acetochlor + terbuthylazine
post-emergence: foramsulfuron + iodosulfuron
RR1: acetochlor (pre) + Roundup (post)
RR2: split Roundup (epost) + Roudup (post)
RR3: Roundup + acetochlor (epost)

37. Trial design

38. Sowing

39. Application of herbicides

40. Some results from 2010
1 year data!

41. acetochlor (pre) + Roundup

42. Roundup 2x (split)

43. Roundup Ready + acetochlor
(EPOST)

44. Harder control in mulch / reduced

45. Herbicide efficacy on AMARE
Roundup + acetochlor (EPOST)
Roundup (EPOST + POST)
acetochlor (PRE) + Roundup
(POST)
foramsulfuron + iodosulfuron
(POST)
acetochlor + terbuthylazinec(PRE)
86 88 90 92 94 96 98 100
efficacy (%)
mulch chisel plough

46. Herbicide efficacy on CHEAL
Roundup + acetochlor (EPOST)
Roundup (EPOST + POST)
acetochlor (PRE) + Roundup
(POST)
foramsulfuron + iodosulfuron
(POST)
acetochlor + terbuthylazinec(PRE)
82 84 86 88 90 92 94 96 98 100
efficacy (%)
mulch chisel plough

47. Herbicide efficacy on ECHCG
Roundup + acetochlor (EPOST)
Roundup (EPOST + POST)
acetochlor (PRE) + Roundup
(POST)
foramsulfuron + iodosulfuron
(POST)
acetochlor + terbuthylazine (PRE)
80 82 84 86 88 90 92 94 96 98 100
efficacy (%)
mulch chisel plough

48. Harvest...

49. Yield assessment
(14% moisture)
Roundup + acetochlor (EPOST)
Roundup (EPOST + POST)
acetochlor (PRE) + Roundup
(POST)
foramsulfuron + iodosulfuron
(POST)
acetochlor + terbuthylazine (PRE)
0 2 4 6 8 10 12
grain yield (t/ha)
mulch chisel plough

50. Experience with NK603 maize
some conclusins
All RR treatments (split; with acetochlor)
showed comparable or better weed control
effects than conventional herbicides
Stable affect through the years
No problems with herbicide selectivity were
observed
Better control of perennial weeds and grasses
Second weed flush was not a serious problem
Better reliability in soil conservation tillage
systems

51. Welcome to our trial!

52. 60 mm rain last week ...