(F71)
COTTON: Gossypium hirsutum L., 'NuCotn33'
PRECISION PLACEMENT OF ALDICARB AT PLANTING FOR THE CONTROL OF THRIPS IN
COTTON, 2001
Kimberly H. Lohmeyer, J. Kurk Lance, and John N. All
Department of Entomology
University of Georgia
Athens, GA 30602
Phone: (706) 542-2856
Fax: (706) 542-2279
E-mail: [email protected]
E-mail: [email protected]
E-mail: [email protected]
Phillip M. Roberts
University of Georgia
Tifton, GA 31793
E-mail: [email protected]
Thrips: Frankliniella spp.
Experiments were conducted at the University of Georgia's Coastal Plain Experiment Station (CPES) and
Plant Sciences Farm (PSF). CPES test treatments were applied to the two middle rows of 15.24 m, four-row
plots. PSF test treatments were applied to the two middle rows of 7.62 m, four-row plots. A RCB design
with four replications was used for both tests with one untreated check per replication. Seed was planted in
a hill method using a two-row Monesem pneumatic planter on 2 May (CPES) and 8 May (PSF). Hills were
spaced 0.305 m apart in 0.965 m wide rows with three seeds per hill. The rows that received precisionplaced insecticide treatments were planted with an open furrow. Temik granules were applied at planting
using two methods: placement of the insecticide in the furrow with the seed, or precision placement of the
insecticide directly on top of the seeds in each hill with a "bazooka". Furrows were closed using a hoe. All
insecticide rates were specified as kg product/ha based on 0.965-m rows. CPES test plots were sampled for
thrips on 14 and 22 May, and 1 Jun. PSF test plots were sampled on 17 and 29 May, and 6 and 18 Jun.
Plants were sampled for thrips by randomly collecting 10 plants from the treated rows of each plot and
immersing the entire plant into a specimen cup filled with alcohol. Samples were taken to the lab, and thrips
were counted and identified using a dissecting microscope. The treated rows of each plot were mechanically
harvested on 16 Oct (CPES) and 1 Nov (PSF). 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.
CPES Test: On 14 May, all treatments significantly reduced thrips populations when compared to the check.
On 22 May, all treatments significantly reduced thrips populations when compared to the check with infurrow aldicarb at 3.92 kg product/ha and precision-placed aldicarb at 5.74 kg product/ha showing the
greatest reductions. All precision-placed treatments except 0.71 kg product/ha were as effective at reducing
thrips as the standard in-furrow 3.92 kg product/ha rate. On 1 Jun, only precision-placed aldicarb at 5.74 kg
product/ha significantly reduced thrips in comparison to the check. All precision-placed treatments were as
effective at reducing thrips populations as the standard 3.92 kg product/ha rate. Plots treated with precisionplaced aldicarb at rates of 0.71, 1.44, 2.87, and 5.74 product/ha had significantly higher yields when
compared to the check.
PSF Test: On 17 May, all precision-placed treatments showed a significant reduction in thrips when
compared to the check and were as effective at reducing thrips populations as the standard 3.92 kg
product/ha rate. Precision-placed aldicarb at 2.87 and 5.74 kg product/ha showed the greatest reduction in
thrips populations. On 29 May, all precision-placed treatments reduced thrips in comparison with the check
and were as effective in reducing thrips as the standard 3.92 kg product/ha rate. Precision-placed aldicarb at
2.87 kg product/ha showed the greatest reduction in thrips populations. On 6 Jun, precision-placed aldicarb
at 2.87 kg per product/ha showed the most significant reduction in thrips in comparison with the check. On
18 Jun, precision-placed aldicarb at 2.87 kg product/ha showed the most significant reduction in thrips
populations. All precision-placed treatments were as effective at reducing thrips as the standard 3.92 kg
product/ha rate. Plots treated with precision-placed aldicarb at 0.18 kg product/ha had significantly higher
yields when compared to the check.