Avaliação da resistência de variedades do milho crioulo a lagarta do cartucho Spodoptera frugiperda (Lepidoptera: Noctuidae)

Abstract

Corn is a fundamental crop in Brazilian agriculture, representing 37% of cereal production. However, the infestation of Spodoptera frugiperda, called fall armyworm, causes significant damage to productivity. Chemical control is common, but caterpillar resistance to pesticides is increasing due to continued application. An alternative is the use of landrace maize varieties, which, although they have lower productivity, demonstrate resistance and genetic adaptability. These varieties are being rediscovered and adopted by family farmers, reducing production costs. The objective of this work was to evaluate the resistance to attack by Spodoptera frugiperda in 4 varieties of landraces maize: Colored Corn, Yellow Popcorn, Black Corn 1 and Black Corn 2 in a controlled environment. A randomized block experimental design was adopted, with the planting of 4 varieties with two replications, which remained in cultivation for 30 days. The 3rd instar caterpillars were prevented from feeding for 2 hours. Each corn variety was cut into 2cm² discs and placed on the caterpillars for 1 hour. At the end of the period, the discs were stored separately with 4 witnesses each. The discs had their image scanned and analyzed in Quant Software, the data on leaf area consumed were subjected to analysis of variance in a completely randomized design and the means compared using the Skott-Knott test at 5%. It is concluded that the studied varieties had an influence on the feeding of S. frugiperda larvae. The Yellow Popcorn and Black Popcorn 1 varieties were consumed less than the others.