Indução de resistência em plantas de grão-de-bico mediada por bacillus amyloliquefaciens e Bacillus subtilis à Spodopetera frugiperda (Lepidoptera : Noctuidae)

Abstract

Chickpea is a globally consumed legume, cultivated in tropical and subtropical climates. It's an annual herbaceous plant with low production numbers in Brazil, which still relies on imports to meet internal demand. This represents an opportunity for national producers, but chickpea production tends to face challenges related to biotic factors, such as pest attacks, particularly from Spodoptera frugiperda. This lepidopteran, in its larvais stage, feeds on leaves and shoots. The use of bacteria like Bacillus subtilis and Bacillus amyloliquefaciens can promote sustainable control against pest attacks. In addition to stimulating plant growth, they also induce plant defenses against herbivores. The study evaluated the efficiency of Bacillus subtilis (Bs) and Bacillus amyloliquefaciens (Ba) in managing S. frugiperda in chickpea cultivation. The experiment was conducted at LabMIP, located at the Federal Goiano Institute, Urutaí Campus – GO. The biological parameters of S. frugiperda, antixenosis, and nutritional indices were evaluated in a completely randomized design (CRD). The results showed that leaves from seeds inoculated with Bs were less attractive to caterpillars (p < 0.001). Caterpillar weight and length showed lower values in treatments with Ba (0.27 g; 2.29 cm) and Bs (0.24 g; 2.17 cm). The total life cycle was more prolonged in caterpillars fed chickpeas treated with Bs (33.9 days). Regarding nutritional indices, feeding with chickpea leaves, treated with and without bacteria, only influenced the ingested food parameter, ranging from 0.32 to 0.42 g. The inoculation of seeds with Bs and Ba negatively induced plant resistance in the biology of S. frugiperda.