(F67) COTTON: Gossypium hirsutum L. 'NuCotn33' REDUCING ALDICARB REQUIREMENTS FOR THRIPS MANAGEMENT ON COTTON UTILIZING STRIP-TILLAGE AND PRECISION PLACEMENT, 2002. Kimberly H. Lohmeyer Department of Entomology University of Georgia Athens, GA 30602 Tel: (706) 542-2816 Fax: (706) 542-2279
[email protected] J. Kurk Lance
[email protected] Phillip M. Roberts
[email protected] David Jenkins
[email protected] John N. All
[email protected] Thrips: Frankliniella spp. Experiments were conducted at the University of Georgia's Plant Sciences Farm. A split-block design with six replications and one untreated check was used. Conventional tillage and strip-tillage blocks had been prepared prior to planting in a field that had been previously planted with wheat. Conventional tillage blocks were plowed and disked twice to prepare a smooth seedbed for planting. Cotton seed was planted on 30 May. Conventional tillage plots were planted using a two-row Monesem pneumatic planter. Strip-tillage plots were prepared with a KMC stripper/subsoiler implement followed by the same Monesem pneumatic planter utilized in the conventional tillage plots. Varying rates of aldicarb (Temik 15% granular) were then applied to the two middle rows of each plot. Granular aldicarb (15G) was applied at planting using two methods: placement of the insecticide along the entire furrow with the seed, or precision placement of the insecticide directly on top of the seed in each hill with a "bazooka." All insecticide rates were specified as kg product/ha based on 1 m wide rows. The open furrows were closed with the packer wheel of an Almaco push planter. Plots were sampled for thrips on 10, 19 Jun, and 2 Jul. Ten plants were randomly selected from the treated rows of each plot and immersed in a specimen cup containing alcohol. Samples were taken to the laboratory where thrips were identified and counted using a dissecting scope. On 23 Nov plots were mechanically harvested and seed cotton was weighed in the field to determine yield. Thrips counts were square root transformed before statistical analysis. Means for thrips sampling and yield were analyzed using Tukey's Studentized Range Test, with P < 0.05. No interactions between tillage practices and aldicarb treatments were observed for any sampling date or for the yield. For all sampling dates, no significant differences in thrips populations were observed between conventional and strip-tillage plots. On 10 and 19 Jun all precision placed treatments significantly reduced thrips when compared with the untreated check and were as effective in reducing thrips as compared to the standard in-furrow 3.92 kg product/ha rate. On 2 Jul, no significant difference in thrips populations was observed for any treatment when compared with the untreated check. Yield from strip-tillage plots was
significantly higher than the yield from conventional tillage plots. No significant differences in yield were observed for any treatment in comparison to the untreated check.
