Silicon as resistance inducer in to control black aphid Aphis craccivora Koch, 1854 in Phaseolus lunatus lima beans

Abstract

In Brazil, there are few records of insects associated with the cultivation of lima beans; among them, there is the black aphid Aphis craccivora Koch, 1854. The objective of this study was to evaluate the effects of silicon application on the resistance induction of lima bean plants, Phaseolus lunatus, to the black aphid A. craccivora. The experiment was conducted in the Entomology Laboratory of the Phytosanitary Sector of Centro de Ciências Agrárias, Universidade Federal do Piauí (UFPI), Brazil. The effects of the following treatments on biological aspects of the insect were evaluated: silicon applied to soil; silicon applied to soil + leaf; silicon applied to leaf; and control, without silicon application. The following biological variables were evaluated: generation period, reproductive period, and the fertility and daily average of produced nymphs per female. Plant silicon and lignin content were also evaluated. A 1% solution of silicic acid (2.0 g of product diluted in 200 mL of water) was applied around the plant stem (on soil), 15 days after emergence. Leaf application was performed with a 1-L spray, 5 days after the soil application. The non-preference of A. craccivora on lima beans was also evaluated. The evaluations were performed after 48 and 72 hours of infestation by counting nymphs and adults at each leaf section. Silicon application reduces nymph production, thereby interfering in the biological aspects of A. craccivora. Therefore, it can be used in cowpea pest management programs.

Reaction of sugarcane genotypes to root-knot nematode parasitism (Meloidogyne javanica and Meloidogyne incognita)

“…A similar result was obtained by FILGUEIRAS et al (2011) studying the application of silicon in the induction of the green wheat aphid Schizaphis graminum. PORTELA et al (2019), researching the effect of silicon on the aphid A. craccivora in the fava bean crop Phaseolus lunatus, concluded that the insect's fecundity is affected by silicon, a result similar to the present study.…”

Feijão-fava: doenças virais e fúngicas

“…e Myzus persicae é a presença de espécies de plantas (hospedeiros naturais), que desempenham papel fundamental nas epidemias do endurecimento dos frutos do maracujazeiro causadas pelo CABMV (GARCÊZ et al 2015). Em feijão-fava são escassos os estudos de transmissão de vírus por afídeos, muito embora seja frequente a ocorrência de Aphis craccivora colonizando plantas em campo (FORTES PORTELA et al 2019). Não existem estudos sobre a transmissão do CABMV por sementes de feijão-fava.…”

“…Na região sul do Estado do Piauí, é comum que produtores de feijão-fava não realizem a eliminação de plantas espontâneas, uma vez que muitas plantações estão localizadas em terrenos acidentados e pedregosos, o que dificulta a realização desse trato cultural. Além disso, o plantio de outras leguminosas no mesmo local e no mesmo período do ano funciona como ponte, permitindo que os vírus sejam intercambiados entre o feijão-fava e demais leguminosas.O manejo dos insetos vetores para o controle das viroses em feijão-fava apresenta alguns desafios, uma vez que os únicos vetores conhecidos capazes de colonizar o feijão-fava são a mosca-branca B. tabacci e o afídeo A. craccivora(FORTES PORTELA et al 2019;RAMOS-SOBRINHO et al 2014). Mais estudos são necessários para conhecer os demais vetores de vírus nessa cultura.…”