Evaluation of the Insect Pest Population Dynamics in Common Bean Cultivars in Relation to the Foliar Fertilisation with Potassium Silicate

Abstract

Effect of foliar fertilisation with potassium silicate on the abundance of pest insects belonging to hemiptera, diptera, coleoptera and lepidoptera in two different genotypes of common bean, cultivated in two sowing seasons. The experiment was conducted under field conditions during the Rainy Season from August to December 2014 and the Dry Season from February to June 2015 in a rural area of Assis Chateaubriand, State of Paraná, Brazil. The experimental design was a completely randomised 2 x 5 factorial design with four replications. The first factor refers to the bean genotypes (IPR Campos Gerais and IPR Tuiuiú), and the second factor refers to the doses of potassium silicate (0.0, 250, 500, 750 and 1000 ml ha-1). Potassium silicate at specified doses were sprayed bi-weekly during phenological stages V3 to R8. Insect pest samplings were carried out weekly during the phenological stages V3 through R8 for both the experiments. Foliar fertilisation with potassium silicate decreased pest insects on the common bean genotypes was studied. IPR Tuiuiú genotype presented a smaller quantity of hemiptera insects in compared to IPR Campos Gerais during the reproductive stage of the Rainy Season Crop (2014). During the vegetative stage of the Dry Season Crop (2015), IPR Campos Gerais presented a smaller quantity of diptera insects in compared to IPR Tuiuiú. Interactions between treatments and the genotypes evaluated occurred, decreasing que population of hemiptera and lepidoptera insects during the vegetative and reproductive stages of the Dry Season Crops (2015). IPR Campos Gerais Genotype represented a smaller quantity of lepidoptera and hemiptera insects than IPR Tuiuiú.