Beauveria bassiana PSUB01 simultaneously displays biocontrol activity against Lipaphis erysimi (Kalt.) (Hemiptera: Aphididae) and promotes plant growth in Chinese kale under hydroponic growing conditions

The mustard aphid, Lipaphis erysimi, is a significant agricultural pest, responsible for yield losses in several vegetable crops. A desire to reduce insecticide applications in green house vegetable production systems has led to increasing use of entomopathogenic fungi to manage pests, including aphids. In this study, we evaluated the efficacy of the entomopathogenic fungus, Beauveria bassiana PSUB01, for the management of L. erysimi in Chinese kale grown hydroponically. Drenching roots and spraying foliage with B. bassiana PSUB01 conidial suspension were used as inoculation methods. Tested conidia concentrations of B. bassiana PSUB01 (10(8) and 10(9) conidia/ml) caused 87-89% mortality in L. erysimi after five days of application. The application of B. bassiana PSUB01 by root drenching colonised all treated parts (root, stem and leaf) with 64.0-96.0% colonisation (based on number of samples tested) in different part of tested plants during 7-21 days after inoculation. The application of B. bassiana PSUB01 on Chinese kale by either foliar spray or foliar spray + drenching of roots had reduced the fecundity of L. erysimi with very few progeny during 6-14 days of treatment. Also, application of B. bassiana PSUB01 by drenching of roots or by combination of foliar spray + drenching of roots enhanced plant growth parameters significantly except root length. These results suggest that B. bassiana PSUB01 could be included as part of an integrated pest management (IPM) plan for the management of L. erysimi under hydroponic production of Chinese kale and other vegetable crops.