Productivity and physiology of kale inoculated with entomopathogenic fungi of Amazon region to control caterpilla

Abstract

The use of biological control agents such as entomopathogenic fungi is an alternative for the control of kale(Brassica oleracea L.) defoliating caterpillars. The objective was to investigate the efficacy of entomopathogenicfungi of Amazon region in the control of defoliating caterpillars in kale and their impacts on the physiologicaland agronomic responses of the crop. Field and greenhouse experiments were conducted in randomized blockdesign and completely randomized design, respectively. The treatments consisted in the application of isolatesof entomopathogenic fungi: Beauveria bassiana, Isaria sp., Metarhizium anisopliae and Trichoderma asperellum.The control treatment consisted of the application of an chemical insecticide based on deltamethrin.Variablesreferring to the development, yield and physiology of the plants were evaluated. Field results revealed thatplants treated with the fungi B. bassiana, M. anisopliae and T. asperellum showed levels of severity, number ofleaves and commercial yield that did not differ from the standard treatment; however, they showed a lowerpopulation density of the defoliating caterpillar complex. The application of the treatments with M. anisopliaeand chemical insecticide showed better photosynthetic performance. In greenhouse, the fungus T. asperellumprovided greater plant height and robustness index in relation to the treatment with chemical insecticide.The entomopathogenic fungi of Amazon region can be contributed to the integrated management of leafdefoliating caterpillars in kale. These microorganisms have similar efficiency with chemical insecticides, beingecologically and economically viable to mitigate the negative impacts caused by the systematic use ofchemicals.