Location: Crop Genetics and Breeding ResearchTitle: Evaluation of strains of Beauveria bassiana and Isaria fumosorosea to control sugarcane aphids on grain sorghum
|Knoll, Joseph - Joe|
|PUNNURI, SOMASHEKHAR - Fort Valley State University|
|NILAND, ERIKA - Wingate University|
Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/9/2020
Publication Date: 6/27/2020
Citation: Harris-Shultz, K.R., Knoll, J.E., Punnuri, S., Niland, E., Ni, X. 2020. Evaluation of strains of Beauveria bassiana and Isaria fumosorosea to control sugarcane aphids on grain sorghum. Agrosystems, Geosciences & Environment. 3:e20047. https://doi.org/10.1002/agg2.20047.
Interpretive Summary: The sugarcane aphid outbreak on U.S. sorghum began in 2013 near Beaumont, Texas and by 2018 it spread to 21 states. Spreading by largely a single ‘super-clone’, this pest caused a yield decline on susceptible sorghum hybrids that ranged from 50-100% in infested fields. To control the sugarcane aphid, two insecticides are used in the U.S. with the same mode of action. As the number of insecticides available are limited to control sugarcane aphid on sorghum, we sought to determine if fungi that are pathogens to insects can be applied to reduce the damage caused by sugarcane aphids. Two strains of Beauveria bassiana and one strain of Isaria fumosorosea as well as water (negative control) and an insecticide Sivanto (positive control) were applied to a susceptible sorghum hybrid in field plots located in Tifton and Fort Valley, Georgia in 2018. As compared to the treatment with water, only the plots treated with Sivanto had less aphids and plant damage as well as more grain yield. Thus, these strains of fungi were ineffective for controlling the sugarcane aphid under our field conditions.
Technical Abstract: The sugarcane aphid [Melanaphis sacchari (Zehntner)] has become a persistent problem to sorghum [Sorghum bicolor (L.) Moench] producers in the United States since its first identification on grain sorghum in Beaumont, Texas in 2013. Since then, this ‘super-clone’ has spread to almost all sorghum growing areas of the country. Growers have managed the sugarcane aphid using Insecticide Resistance Action Committee (IRAC) Group 4 insecticides and the use of resistant hybrids. In order to provide additional methods of control especially for organic sorghum production, two strains of the fungal entomopathogens Beauveria bassiana and one strain of Isaria fumosorosea as well as water and Sivanto (flupyradifurone) were applied to sugarcane aphid susceptible sorghum hybrid DKS53-53 in a randomized complete block design (RCBD) with four replications at Tifton and Fort Valley, GA. Aphid number, plant damage, grain yield, dry biomass, and plant height were measured for each treatment. As compared to the treatment with water, only the plots treated with Sivanto had significantly less aphid number and plant damage and significantly more grain yield and increased plant height. Thus, the applied entomopathogens did not reduce sugarcane aphid population numbers, did not reduce plant damage, and did not increase grain yield in either location as compared to treatment with water (the negative control). Thus, these strains of entomopathogens were ineffective for controlling the sugarcane aphid under these field conditions.