1) The study evaluated the efficacy of weed control in glyphosate-resistant maize under different treatment conditions in Poland. 2) Weed counts showed that treatments containing glyphosate effectively controlled most weed species, while a standard herbicide was also effective. 3) Maize yields were not significantly different between treatments. 4) Soil samples contained seeds from 8 weed species, with poppy, lamb's quarters, and barnyard grass being most abundant.

1. Tadeusz Praczyk
Institute of Plant Protection – National Research Institute
Poznań, Poland
Praha, 15.06.2011

2. The focus of the studies
Efficacy of weed control in glyphosate‐resistant maize
(NK603) under Polish conditions.
The influence of glyphosate on biodiversity in
comparison to standard weed control systems.

3. TREATMENTS
Herbicides Doses Time of application
[L/ha] [BBCH]
1. Guardian Max 840 EC + Roundup Ready 1.5 + 3.0 12‐13
Roundup Ready 3.0 16‐17
2. Roundup Ready 3.0 12‐13
Roundup Ready 3.0 16‐17
3. Lumax 537,5 SC 4.0 12‐13
4. Mocarz 75 WG 0.2 kg 12‐13
Milagro 040 SC 1.5 16‐17
Roundup Ready (glyphasate)
Guardian Max 840 EC (acetochlor )
Lumax 437,5 SC (mezotrione + S-metolachlor + terbuthyloazine)
Mocarz 75 WG (tritosulfuron + dicamba)
Milagro 040 SC (nicosulfuron)

4. Trial layout
Field with crop rotation Field with monoculture of NK603
(NK603 - oats - NK603) (3 yers)
4 3 2 1 4 3 2 1
401 402 403 404 405 406 407 408
2 1 4 3 2 1 4 3
301 302 303 304 305 306 307 308
3 4 1 2 3 4 1 2
201 202 203 204 205 206 207 208
1 2 3 4 1 2 3 4
8m
101 102 103 104 105 106 107 108
9m
4 treatments
4 replications

5. Planting of corn NK603

6. Corn NK 603 at early growth stage

7. Number of weeds per 1 m2 (field 1, 9 June, 2009)
Traetments Chenopodium Viola Polygonum Echinochloa Elymus
album arvensis persicaria crus galli repens
1 16,9 17,7 2,3 9,9 0,3
2 46,9 68,1 29,5 275,1 0
3 1,2 2,4 0 0,2 0
4 40,6 43,4 0,3 310,3 0

8. Number of weeds per 1 m2 (field 2, 9 June, 2009)
Traetments Chenopodium Viola Polygonum Echinochloa Elymus
album arvensis persicaria crus galli repens
1 5,1 64,1 0,5 0,1 29,8
2 22,6 106,3 22,1 9,7 23,3
3 0,2 1,5 0,1 0,3 40,9
4 11,4 53,1 0,3 55,1 69,7

9. Number of weeds per 1 m2 (8 June, 2010)
Traetments Chenopodium Viola Polygonum Echinochloa Elymus
album arvensis convolvulus crus galli repens
1 2.2 13.4 2.3 2.4 0.7
2 1.9 7.6 1.1 10.7 0.8
3 0 0 0 3.9 5.4
4 0.8 15.3 0.7 43.8 4.1

10. Guardian Max 840 EC + Roundup Ready
1.5 + 3.0 l/ha(BBCH 12‐13)
Roundup Ready ‐ 3.0 l/ha (BBCH 16‐17)
19th June, 2010

11. Guardian Max 840 EC + Roundup Ready
1.5 + 3.0 l/ha(BBCH 12‐13)
Roundup Ready ‐ 3.0 l/ha (BBCH 16‐17)
12th August, 2010

12. Guardian Max 840 EC + Roundup Ready
1.5 + 3.0 l/ha(BBCH 12‐13)
Roundup Ready ‐ 3.0 l/ha (BBCH 16‐17)
20th October, 2010

13. Roundup Ready ‐ 3.0 l/ha (BBCH 12‐13)
Roundup Ready ‐ 3.0 l/ha (BBCH 16‐17)
19th June, 2010

14. Roundup Ready ‐ 3.0 l/ha (BBCH 12‐13)
Roundup Ready ‐ 3.0 l/ha (BBCH 16‐17)
12th August, 2010

15. Lumax 537,5 SC – 4.0 l/ha (BBCH 12‐13)
19th June, 2010

16. Lumax 537,5 SC – 4,0 l/ha (BBCH 12‐13)
12th August, 2010

17. Mocarz 75 WG – 0.2 kg/ha (BBCH 12‐13)
Milagro 049 SC – 1.5 l/ha(BBCH 16‐17)
19th June, 2010

18. Mocarz 75 WG – 0.2 kg/ha (BBCH 12‐13)
Milagro 049 SC – 1.5 l/ha(BBCH 16‐17)
12th August, 2010

19. Yield of corn NK603 in 2009
Treatments Dose Field 1 Field 2
[L/ha] [t/ha] [t/ha]
Guardian Max 840 EC + Roundup Ready 1.5 + 3.0 6,58 7,90
Roundup Ready 3.0
Roundup Ready 3.0 7,92 7,77
Roundup Ready 3.0
Lumax 537,5 SC 4.0 7,07 7,26
Mocarz 75 WG 0.2 kg 6,67 7,04
Milagro 040 SC 1.5
LSD(0,05) 2,140 2,116

20. Yield of corn NK603 in 2010
Treatments Dose Yield
[L/ha] t/ha
Guardian Max 840 EC + Roundup Ready 1.5 + 3.0 10.03
Roundup Ready 3.0
Roundup Ready 3.0 10.74
Roundup Ready 3.0
Lumax 537,5 SC 4.0 9.94
Mocarz 75 WG 0.2 kg 8.71
Milagro 040 SC 1.5
LSD(0,05) 2.125

21. Studies on seed bank in soil

22. Methodology
Taking of soil samples: before corn emergence (May)
Number of samples: 4 from each plot
Depth of soil sampling: 0-30 cm
Diameter of drill: 5 cm
Volume of sample: 588.75 cm3

23. Taking of soil samples

24. Soil samples in flat pans in glasshouse

25. Weed species in soil seed bank
Chenopodium album Matricaria inodora
Viola arvensis Echinochloa crus galli
Thlaspi arvense
Papaver rhoeas

26. Number of living seeds per 1000 cm3 of soil in 2009
(field 1)
Treatm. CHEAL VIOAR PAPRH MATIN THLAR CAPBP ECHCG APESV
1 53.3 1.8 0.3 0.3 0 0 98.8 0.3
2 29.5 1.9 0 0 1.8 0.7 30.0 0.3
3 35.6 3.7 1.2 0.8 0 0 29.6 0.1
4 38.9 1.5 0.6 0 6.1 0 76.4 0.3

27. Number of living seeds per 1000 cm3 of soil in 2009
(field 2)
Treatm. CHEAL VIOAR PAPRH MATIN THLAR CAPBP ECHCG APESV
1 189.9 4.3 2.2 1.4 1.0 0.4 2.2 7.8
2 135.3 9.5 0.9 1.0 5.1 0.9 9.5 6.9
3 131.0 7.4 0.7 0.6 0.9 0.4 4.5 6.1
4 122.4 6.4 0.8 1.4 2.6 1.4 35.3 4.6

28. Number of living seeds per 1000 cm3 of soil
(field without NK603 in 2010)
Treatm. CHEAL VIOAR PAPRH MATIN THLAR VERPE ECHCG APESV
1 11.4 0.5 13.4 0 0 2.1 29.1 0.3
2 13.5 1.1 10.0 0 0 0 19.0 0
3 11.3 0.8 11.8 1.9 0 0.1 34.5 0
4 13.5 2.0 10.9 0 0.3 0.1 18.6 0.1

29. Number of living seeds per 1000 cm3 of soil
(field withNK603 in 2010)
Treatm. CHEAL VIOAR PAPRH MATIN THLAR ECHCG APESV
1 23.0 1,0 79.8 0.4 0 7.9 2.8
2 23.8 1.5 63.6 0 0 9.8 2.3
3 13.8 2.1 75.4 0 0.1 6.0 2.0
4 18.4 2.1 64.9 0.4 0.3 8.9 4.4

30. Conclusions
Experimental field was infested mainly by following weed
species: Chenopodium album, Viola arvensis, Papaver rhoeas,
Echinochloa crus galli, Elymus repens.
Treatments with Roundup Ready and Guardian Max 840 EC +
Roundup Ready were very effective against all weed species.
Standard herbicide Lumax 537,5 SC applied at BBCH 12‐13
gave similar effect compared to treatments with glyphosate.
The system of weed control did not influence yield of maize.
In soil samples 8 weed species were found (Papaver rhoeas,
Chenopodium album and Echinochloa crus galli were most
abundant).