Resistance Induction in Zea mays L. Cultivars against Spodoptera frugiperda (Lepidoptera: Noctuidae)

Abstract

The maize crop Zea mays L., faces serious limitations in cultivation due to attack by the Spodoptera frugiperda. The objective of this work was to evaluate the resistance induction in maize cultivars with Spodoptera frugiperda caterpillars due to the application of silicon (Si) and calcium (Ca) sources. Two cultivars of maize viz., Genotype A simple hybrid and the Creole Genotype B variety were used. These cultivars were submitted to two treatments of foliar fertilisation, calcium chloride and potassium silicate, and treatment without the application of an elicitor. The evaluations of the damages caused by the S. frugiperda caterpillar were carried out weekly, from the seventh day after the first application of the products (Si and Ca). In the bolting phase (VT), physiological evaluations of gas exchanges and fluorescence of chlorophyll a were carried out. For the Creole variety, there was a pre-dominance of plants that did not present any damage. The Creole variety presented the lowest mean of infestation by S. frugiperda, regardless of the product applied. No statistical differences were recorded between the products applied in each cultivar. The maximum quantum efficiency of FSII (FV/FM) was not statistically significant for the cultivars nor the cultivars x treatments interaction. For stomatal conductance (gs), a statistical difference between cultivars was found. In the Creole Genotype B variety, superior results were obtained in relation to the simple hybrid. The TF variable did not present statistical difference between the evaluated cultivars. Different behaviours were observed in the transpiration variable (E) among the cultivars. In the Creole Genotype B variety when submitted to silicon application and in control, higher transpiration was obtained compared to the simple hybrid. The sources of silicon and calcium do not promote the induction of resistance to S. frugiperda in the studied variables. The Creole variety Genotype B of Zea mays suffers minor damage due to an infestation of S. frugiperda in relation to the Genotype A simple hybrid maize.