INTEGRATION OF GENOTYPES OF MAIZE (Zea mays L.) AND PLANT POWDERS AGAINST Sitophilus zeamais Motschulsky (COLEOPTERA: CURCULIONIDAE)

The objective of this study was to determine the combined effect of maize (Zea mays L.) genotypes with the application of epazote (Dysphania ambrosioides L.), castor oil plant (Ricinus communis L.), Mexican pepperleaf (Piper auritum Kunth), moringa (Moringa oleifera Lam.), neem (Azadirachta indica A. Juss.), and Pacific Coast mahogany (Swietenia humilis Zucc.) as an alternative to control the maize weevil (Sitophilus zeamais Motschulsky). It was hypothesized that combining certain maize genotypes with specific plant powders would significantly reduce S. zeamais damage without affecting germination. Three bioassays were conducted. In the first, the biological activity of six plant powders to control weevil populations and their impact on seed germination was evaluated; in the second, the effect of the hardness of three maize hybrids and the “Ancho Pozolero” variety on weevil was determined; and in the third, the interaction between genotypes and the most effective powders was explored. With five replicates per treatment and a control without application, 100 g of maize and 1 % plant powder were placed in 250 mL glass containers using a fully randomized design. Mortality, emergence, insect damage, and maize germination were assessed. In the evaluation of plant powders, D. ambrosioides and S. humilis stood out for their insecticidal and insectistatic effects and protection of maize, although they affected germination by 6.5 and 7.2 %, respectively. P. auritum showed good insecticidal and insectistatic effects without affecting germination. The hybrid “Tlaoli Puma,” classified as hard, reduced the damage caused by S. zeamais by one third. The combination of the hybrid “Tlaoli Puma” with 1 % plant powder of D. ambrosioides or S. humilis reduced the chances of attack and damage by S. zeamais, contributing to reducing post-harvest losses of stored maize and thus validating the hypothesis.