Seed and fo= liar insecticide treatment of soybean for control of bean leaf beetles in 2004

Doug Johnson, Extension Entomologist

Department = of Entomology

College of Agriculture - University of Kentu= cky

Methods & Procedures

Plots of Asgrow Ag3703 RR soybeans were planted on the= University of Kentuc= ky, Research and Education Center on 25, May 2= 004 using a John Deere MaxEmerge 2, no-till planter, calibrated to deliver nine seeds per row foot. Plots wer= e 4, 30" rows by 25' long. No-tillage culture was used and a tank mix of the herbicides, Roundup at 1 Qt / A., Canopy at 6.0 fl.oz. /A and Duel II at 1pt./A, was applied on 5/20/04. All seed was treated with Rival + Allegiance fungicides applied= by Gustafson¹. The study was planted as a randomized complete block design (Steel and Tory 1960) with five replications. Treatments were random= ly assigned using SAS AProc Plan@ (SAS 2000)= .

All non-insecticide treated seed were planted first. A= ll plots with a specific insecticide treated seed were planted before changing= to treatments with other insecticides. In plots that received “insectici= de seed treatments”, the two center rows were planted with treated seeds= and the two outer rows were untreated. Gustafson applied all insecticide seed treatments¹. Four untreated rows were planted around the complete circumference of the test. In plots that received a “foliar treatment” the insecticide was applied using a CO₂ powered, back-pack sprayer, calibrated to deliver twenty= gallons per acre at 45 PSI pressure and = four miles per hour, through four 8003 nozzles on 18” centers. Growth stage (GS) designations are from Fehr and Caviness (1977).

The treatments are as follows:

1. Untreated

2. Gaucho FS, 62.5 G A/100 KG (1.0 oz. A/CWT)<= /p>

3. Cruiser FS, 30 G A/100 = KG (0.48 oz. A/CWT)=

4. Gaucho FS, 62.5 G A/100 KG (1.0 oz. A/CWT) + Bayth= roid 2 EC, 35 GM A/HA (2 fl.oz/A)@ GS:V2

5. Baythroid 2 EC, 35 GM A= /HA (2 fl.oz/A) @ GS: V2

6. Warrior 28 GM A/HA (3.2 fl.oz/A) @ GS: V2

7. Baythroid 2 EC, 35 GM A= /HA (2 fl.oz/A) @ GS: V2@ GS: V2 and R4

8. Warrior 28 GM A/HA (3.2 fl.oz= /A) @ GS: V2 and R4

Foliar applications were made a= t two plant stages. The first was on 29 June 04 at GS V2-3 (trts. 4-8) and the second on 29 July 04 at GS: R4 (trts. 7 & 8).

Insects: Insect populations were monitored on a weekly basis using a three foot “shake cloth” (Barnes and Jones 1970). Additionally, bean leaf beetle populations were monitored in an adja= cent field. One half of the field was in a cover crop of grass and red clover, t= he other half was planted to soybean. The clover/grass mixture was sampled until the soybeans emerged. Afterwards the soybeans were sampl= ed. Each sample consisted of 10 sets of 20 sweeps. Data were standardized as beetles = per 100 sweeps per sample date.

Virus Symptoms: On 08 September all untreated p= lots were visually evaluated for virus symptoms.

Yield: At harvest time plots were trimmed to a = length of twenty feet. On 29 September 04, the two center rows of each plot were harvested using a Hege 125c “small plot” combine. Plot yields were standardized to b= ushels per acre at 60 pounds per bushel and 13 percent moisture.

Results & Discussion

Foliar applications: Plant emergence was somewh= at uneven, which made it difficult to apply the foliar treatments based solely= on plant stage. Therefore, the “V2” stage applications were made b= ased on sweep net counts of Bean leaf beetle adults. The application was timed to occur as the BLB 1^st summer population was beginning to peak (See Figure 1.).

Insects: Populations of insects in the plots we= re trivial. A variety of insects, (e.g. bean leaf beetle, green cloverworm, grasshoppers, Japanese beetle, green stinkbug, yellow striped armyworm, str= iped cucumber beetle etc.) were collected from the plots. However, no populations were even remotely large enough to be analyzed.

Virus Symptoms: Visual examination of untreated= plots indicated that there were insufficient viral symptoms to warrant sampling a= nd analysis.

Yield: There were no significant differences in either yield or test weight due to treatments (Table 1.).

Ta= ble 1. Yield of soybean plots on the UK-REC in Princeton. KY treated with various seed and foliar applied insecticides in the 2004 growing season.
	Yield ±SE	Test Weight ± SE<= /b>
Treatment	n	(Bu./A)	(60 lb. / Bu.)
1. Not Treated	5	57.4 ± 3.4<= /p>	56.3 ± 0.2
2. Gaucho FS, 1.0 oz. A/CWT=	5	58.6 ± 4.2	56.5 ± 0.2
3. Cruiser FS, 0.48 oz. A/CWT	5	61.9 ± 2.8	56.5 ± 0.1
4. Gaucho FS, 1.0 oz. A/CWT + Baythroid 2 EC, 2 fl.= oz/A @ GS:V2	4	58.8 ± 4.3	56.3 ± 0.2
5. Baythroid 2 EC, 2 fl.= oz/A @ GS: V2	5	55.8 ± 4.0	56.5 ± 0.2
6. Warrior 3.2 fl.oz/A @ GS: V2	5	58.6 ± 4.2	56.5 ± 0.2
7. Baythroid 2 EC, 2 fl.oz/A @ GS: V2@ GS: V2 and R4	5	57.7 ± 5.4	56.3 ± 0.1
8. Warrior 3.2 fl.oz/A @ GS= : V2 and R4	4	53.7 ± 1.3	55.9 ± 0.4
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ANOVA of Yield was not significant for treatment at = F(7, 26) =3D 0.63, Pr>F =3D 0.7261 ANOVA of Test Weight was not significant for trea= tment at F(7, 26) =3D 1.03, Pr>F =3D 0.4374

References

Barnes, G= ., and B. F. Jones. 1970. Control of insects on Soybeans. <= st1:State w:st=3D"on">Arkansas Agric. Ext. Leaflet 193: 1-5.=

Fehr, W. and C. Caviness. 1977. Stages of soyb= ean Development. SR80. Iowa State University, Ames, IA.

SAS system for Windows V8.1. 2000. SAS Institute, Cary, N= C.

Steel, R. and J. Torrie. 1960. Principles and Procedur= es of Statistics. McGraw-Hill, NY.

Acknowledgements

The author appreciates Bayer CropScience‘s finan= cial support of this work.

I wish to acknowledge my colleagues in the Department = of Agronomy for use of their planting and harvesting equipment and especially = Mr. John James for operating the equipment. I also thank Dr. David Uhr of Monsa= nto for hustling up soybean seed on short notice. Special thanks to Dr. Said Gabrial for viewing the plots for virus symptoms. I also wish to acknowledge Ms. Andrea Clement, Ms. Linda Overfield, and Ms. Patty Lucas, for their aid= in conducting this project and Ms. MaryAnn Kelley for preparing the manuscript= .