Insecticidal Control of Sugarcane Aphid, 2015*

Heavy infestations of sugarcane aphid (SCA) can kill grain sorghum plants or reduce/prevent head emergence, which can lead to complete crop loss if left untreated. The trial was conducted at the University of Arkansas Northeast Research and Extension Center in Keiser, AR on ‘83P17’ grain sorghum. Six row plots were planted on 38-inch row spacing on 17 May. A RCB design consisting of four replications of eight treatments and an untreated check was used. Insecticide applications were made 25 Aug using a high clearance sprayer at a speed of 3.5 mph and 55 psi with two hollow-cone TX6 nozzles spaced 19 inch apart per row delivering 10.25 gpa. The lower surfaces of 10 leaves in the upper and lower canopy were visually rated for aphids. Mean number of aphids/lower leaf and mean number of aphids/upper leaf at 7 DAT and 14 DAT is reported. Data were subject to ANOVA using ARM (version 16.0) at a mean separation of α = 0.05.

Significant reduction in SCA on lower and upper leaves was observed with Transform 1.5 oz/acre and Sivanto 7 oz/acre at 7 DAT (Table 1). Transform 0.75 oz/acre or 1 oz/acre and Sivanto 4 oz/acre or 5.5 oz/acre provided reduction on upper leaves. At 14 DAT, only Sivanto 4 oz/acre provided significant reduction in SCA populations on upper leaves. Neither Grandevo nor Venerate XC had any significant effect on aphid populations at 7 or 14 DAT. Sivanto at all three rates was the only insecticide to provide a yield advantage compared with the untreated check.

Author notes