Early Season Insect Control with Orthene in Selected Formulations and Application Methods, 1992

Abstract

Abstract The insecticidal efficacy, effect on plant growth, and seed cotton yields of selected Orthene treatments applied as in-furrow sprays at planting (IFSAP), in-furrow granules at planting (IFGAP) and preemergence soil applied sprays (PRE) were compared with that of Temik 15 G. Plots consisted of 4 rows on 101.6 cm centers x 15 m. Treatments were arranged in a RCB design with 4 replications. Cotton was planted in a Gigger Silt Loam (pH = 6.7, 1.8% organic matter) on 23 Apr with a John Deere 7300 planter modified to apply pesticides through a granular applicator hopper box or as a directed spray into the seed furrow. IFSAP treatments were applied with a CO2 charged delivery system calibrated to deliver 46.8 liters total spray/ha through Teejet 8002 flat fan nozzles (1/row) at 3.66 kg/cm2. The PRE treatments were applied on 23 Apr with a tractor mounted boom and compressed air system calibrated to deliver 93.6 liters total spray/ha through Teejet X-12 nozzles (2/row) at 2.81 kg/cm2. Numbers of thrips and aphids were determined by sampling 10 plants on 20 and 25 May using whole-plant washing procedures. Plant stand, leaf area and plant height were measured on 15, 26 and 28 May, respectively. Yields were measured by harvesting the 2 center rows of each plot on 17 Sep and 1 Oct. All plots received Terraclor Super-X (11.2 kg form/ha) at planting as a standard fungicide treatment. Soil moisture was adequate at planting and 90% emergence was observed by 10 d after planting. The entire test was furrow irrigated throughout the season and rainfall was not considered a factor influencing final yields.