Inducers of resistance in potato and its effects on defoliators and predatory insects

The effects of chemical inducers of plant resistance on folivorous beetles and predatory insects in Solarium tuberosum L. were evaluated. The effects of these chemical inducers on crop development and yield were also determined. The experiment was conducted with cv. Emeraude using a randomised complete-block design with four treatments and six replications: 1 - control; 2 - 1% silicic acid; 3 - 0.02% acibenzolar-S-methyl (ASM); and 4 - 1.15% diatomaceous earth (DE). Treatments 2, 3 and 4 were applied by spraying plant foliage every 10 days, total of five applications. The injuries and damages caused by beetles were evaluated. There were no significant differences in the presence of folivorous and predatory beetles in the aerial plant mass and the surrounding soil. However, the plants treated with silica or DE were less preferred by defoliators. Spraying with silicic acid, ASM and DE produced significant increases in plant diameter and height without affecting productivity. The application of silicic acid, ASM or DE increased protection against herbivorous insects and decreased tuber damage.