Application condition and performance of glyphosate in Turkey Prof. Dr. M. Nedim DOGAN Adnan Menderes University, Faculty of Agriculture, Dept. Plant Protection, Weed Science AYDIN-TURKEY email@example.com A project supported by Monsanto
GLYPHOSATE IN TURKEYPerennial cropsAbout 70 % of fruit growers in Aydin province use glyphosateRoadsides, Railways, Irrigation channels and other non agriculturalareasIn cotton prior to harvest as desiccantMany different formulationsSatisfactory effect against most weed species
GLYPHOSATE IN TURKEY However, it is reported by Monsanto people from Turkey that herbicide fails in controlling• Sorghum halepense L. (Pers.) Johnsongrass• Cyperus rotundus L. Purple nutsedge• Portulaca oleracea L. Common purslane• Convolvulus arvensis L. Field bindweed
What can be the reason ?• Some problems concerning application and timing OR• Resistance
AIM of the project with Monsanto• Formulation• Spray water volume• Spray water quality• Weed growth stages• Climatic conditions during application
Pot experiments were carried out in the screenhouse Methodsof the weed science laboratory at Adnan Menderes Pot experimentsUniversity, Faculty of Agriculture, Turkey. Perennialweeds were grown from rhizomes and P. oleraceafrom seeds. A growing medium of turf: sand: perlit andsoil (1:1:1:1) was used for plant growth.
Rhizomes of S. halepense were planted in 3.8 l pots andrhizomes of C. rotundus, C. arvensis and seeds of P.oleracea were in 3.0 l pots.
Four different glyphosate formulations were used in all experimentsFormulation Trade name Glyphosate content (g a.e./l)MON 79376 Roundup Star 360MON 79351 Not commercial yet 480 in TurkeyMON 78273 Cayenne 540Generic Product Sonround 360
Glyphosate was applied at three doses2160 g a.i./ha Recommended dose1620 g a.i./ha 75 % of the recommended (25 % reduced)1080 g a.i./ha Half dose (50 % reduced)
All herbicide treatments were done by using a spray chamber.First the recommended doses of each formulation wereadjusted. Other doses were then obtained as water dilutions.
MODUL I.Effect of water volume on the efficacy of glyphosate•Water volume 200 and 600 l/ha• 600 l/ha water volume was achieved by running 3 times(each with 1/3 spilt dose)•Experiments were carried out two times.•Average plant heights at the beginning of the experiments• Johnsongrass 25 and 22 cm, resp.•Purple nutsedge 5-6 leaves.•Common purslane 1-3 branches.
Relative fresh weights (%) of tested weed species as affected by water volume Common PurpleWeed species Johnsongrass purslane nutsedge **Experiment NS NS I IIWater volume 200 600 200 600 200 600 200 600(l/ha)Untreated 100 100 100 1001080 g a.i./ha (50 %) 8,7 b 37,1 a 1,6 b 18,0 a 34,2 a 41,4 a1620 g a.i./ha (75 %) 4,5 a 15,7 a 0,3 a 1,9 a 15,6 b 26,0 a2160 g a.i./ha NS 2,7 a 5,9 a 0,0 a 0,4 a 8,2 b 22,4 a(recommended)SEM 4,02 2,91 3,96Formulation NS, Results are average of all formulations
Johnsongrass treated with half dose of glyphosate in 200 l/ha volumeJohnsongrass treated withhalf dose of glyphosate in600 l/ha volume
200 l/ha600 l/ha
MODUL IIEffect of water quality on the efficacy of glyphosateJonhsnograss: 33,6 – 50 cm heightCommon purslane: 2-4 branchesPurple nutsedge: 5-6 leavesThree different spray water having different characteristics• Clean soft water•Clean hard water (CaCl2 added)•River water (from Great Meander River)
Properties of spray water used in Experiments Clean water Clean + CaCl2 River waterTotal 1,12 21,84 22,40Hardness (very soft) (hard) (hard)(German)pH 6,31 6,64 7,56EC (µS/cm) 46 846 1008K (me/l) 0,10 0,09 0,34Ca (me/l) 0,10 7,35 2,37Na (me/l) 0,19 0,23 3,58Mg (me/l) 0,08 0,17 5,11
Relative fresh weight (%) of Sorghum halepense and Cyperusrotundus as affected by spray water qualityWater quality S. halepense* C. rotundus**Dose (g a.i./ha) 1080 1080 1620 2160 (50 %) (50 %) (75 %) (100 %)Untreated control 100Clean water 4,4 b 21,7 c 18,0 b 6,0 aClean water + CaCl2 5,4 b 43,1 b 24,9 ab 11,9 aRiver water 63,8 a 73,0 a 30,7 a 13,6 aSEM 2,33 4,23Formulation NS, Results are average of all formulations
1 2 3 4 1 2 3 4 1. Untreated 2. Clean soft water 3. Clean hard water 4. River water 1 2 3 4 Half dose 1 week after treatment
1 2 3 41. Untreated2. Clean soft water3. Clean hard water4. River water 1 2 3 4 Recommended dose 1 week after treatment
Effect of weed growth stage on the efficacy of glyphosate•Water volume: 200 l/ha•Growing weeds within different intervals•Treatment at the same timeGrowth stages Early Middle LateJohnsograss: 22 cm 40 cm 80 cmCommon purslane: 3-4 branches 5-6 branches floweredPurple nutsedge: 3-4 leaves 6-8 leaves 13-14 leaves
Effect of weed growth stage on the efficacy of glyphosate on Sorghum halepenseRelative fresh weight (%) of Sorghum halepense as affected by growth stageDose (g a.i./ha) 1620 (75 %) 2160 (100 %)Growth stage Early Middle Late Early Middle LateUntreated 100 100Glyphosate 0,8 b 3,9 b 19,7 a 0,8 b 3,0 b 17,4 aSE 2,8
11 22 33 441 2 3 4Early Middle22 cm 40 cm 1. Untreated 2. 1080 g 3. 1620 g 4. 2160 g Late Half dose 2 weeks 1 2 3 4 after treatment 80 cm
Effect of weed growth stage on the efficacy ofglyphosate on Cyperus rotundusDose (g a.i./ha) 1620 (75 %) 2160 (100 %)Growth stage Early Middle Late Early Middle LateUntreated 100 100Glyphosate 100 a 43 b 88,9 a 53,6 a 3,7 b 36,8 aSE 9,8Dose (g a.i./ha) 1620 (75 %) 2160 (100 %)Growth stage Early Middle Late Early Middle LateUntreated 100 100Glyphosate 29,5 b 16,9 b 100,0 a 6,8 b 12,1 b 48,4 aSE 7,1
1 2 3 4 1 2 3 4Early 3-4 leaf Middle 6-8 leaf 1. Untreated 2. 1080 g 3. 1620 g Recommended 4. 2160 g dose 3 weeks after treatment Late 10-13 leaf 1 2 3 4
Effect of weed growth stage on the efficacy of glyphosate on Portulaca oleraceaDose (g a.i./ha) 1620 (75 %) 2160 (100 %)Growth stage Early Middle Late Early Middle LateUntreated 100 100Glyphosate 2,7 c 25,0 b 52,9 a 1,4 c 23,1 b 49,8 aSE 4,0Dose (g a.i./ha) 1620 (75 %) 2160 (100 %)Growth stage Early Middle Late Early Middle LateUntreated 100 100Glyphosate 5,3 c 100,0 a 86,3 b 3,5 c 86,3 a 60,4 bSE 9,0
RESULTAll investigated factors influenced theperformance of glyphosate on all weed speciesEarly growth stages, low water volume andclean spray water affected the glyphosateperformance positivelyHerbicide formulation was not importantRecommended dose provided in most casesreliable weed control
Problem weeds reported by Monsanto people in TurkeyJohnsongrass: Quite sensitive to glyphosate even at the larger growth stages. Problems can be attributed to misapplications, low doses in combination with wrong water volumes and low water qualityCommon purslane: Quite sensitive to glyphosate only at early growth stages, but the sensitivity is lower as plants become older. Water volume and quality affected the glyphosate performance on this weed slightly Problems can be associated with wrong application timings (larger growth stages and/or low application doses
Purple nutsedge:• Less sensitive than other two species, only recommendeddose with low water volume, good water quality andsuitable growth stages provide satisfactory weed control•Problems can be associated with all investgated factors,but still more investgations are needed to improve theefficacyField bindweed: ???
Further Studies (Pot Experiments) Effect of climatic factors during application time (time of day) on glyphosate efficacyIn these experiments, interactions between the climatic conditionsduring the application and glyphosate efficacy will be evaluated.Herbicide treatments will be done in the morning early, duringmidday and at the evening.Temperature, humidity and light conditions will be recordedInteractions among water volume, water quality, growth stagesand application time (time of day)
Further Studies (Field Experiments)• Since results showed that purple nutsedge (C. rotundus) was real problem, this weed will be aimed in field experiments• Since it was not possible to work with field bind weed (C. arvensis) in pot experiments, a field experiment will be also conducted for this weed• 2 glyphosate formulations X 2 water quality X 2 growth stages X 2 application times (time of day) X 3 replications• An experiment with C. arvensis has started on 11‐12th June 2011 in a fig orchard in Aydin ‐ Turkey
Significant thanks to Monsanto for financial supportDuring field experiment, 10.06.2011