Uso de produtos alternativos à base de silício e cobre, em comparação ao fungicida na redução da severidade de doenças e sob aspectos de rendimento do feijoeiro

Abstract

Beans are a culture of great importance in the national economy. However, it is very susceptible to diseases that are responsible for production losses and the reduction of crop productivity, generating the use of high doses of pesticides for their control, which end up contaminating the environment and man himself. Therefore, it is necessary to adopt more sustainable control practices, such as the use of silicon and copper. Therefore, the present work proposed to test the potential of silicon, in association with a fungicide, and of the Bordeaux mixture. The experiment was carried out from October 2016 to January 2017, in the experimental area of the Fronteira Sul Federal University - Cerro Largo campus. The experimental design was the completely randomized (DIC) with four replicates. The treatments were constituted of the foliar application in the culture of the silicon, copper and fungicide beans. For the silicon, the Supa silica product was used as the source, containing in its composition a total of 20% Si combined with humic acid at a dose of 0.5 L ha -1; as the copper source, the Bordeaux mixture was used in 0.2% concentration; for the fungicide a product composed of Trifloxystrobin + Prothioconazole was used at the doses of 87.5 ± 75.0 g i. a. ha-¹. Thus, the treatments were arranged as follows: T1 - Witness (without application), T2 - Si, T3 - Fungicide, T4 - Si + Fungicide T5 - Calda Bordalesa. Two applications of the products were carried out at stages R5 and R7, two evaluations of leaf disease severity and one evaluation of pods severity. In addition, growth and productivity variables were also evaluated. It can be concluded that for the anthracnose, treatments consisting of silicon and Bordeaux syrup reduced the severity in the leaves of the upper third, but did not influence the severity of the pods. On the other hand, the application of fungicide, silicon + fungicide and Bordeaux syrup were efficient in reducing the severity of leaves and pods. For yield aspects, treatments T3, T4 and T5 benefited the weight of a thousand grains and productivity.