Produtos fitossanitários aplicados em diferentes espectros de gotas, e suas consequências sobre a diversidade de polinizadores no girassol.

Abstract

Bee-mediated pollination contributes both to the maintenance of plant diversity and to increased agricultural production. Studies have shown a decline in bee populations, which may be linked to the indiscriminate use of pesticides, mainly insecticides, herbicides and fungicides. These can be applied in different droplet spectra changing their environmental fate. Sunflower (Helianthus annuus L.) is an economically important crop that demands both the use of these products and the great need for pollinators. Thus, this study aimed to evaluate the effect of different pesticides, applied in different droplet sizes, on sunflower pollinators diversity. The study was carried out at Água Limpa Farm, belonging to the Universidade Federal de Uberlândia, in a randomized block design, with a 3x2+1 factorial scheme, consisting of 3 pesticides (fungicide, herbicide and insecticide) and 2 droplet spectra (thin and extremely thick) plus one additional treatment (control) without any application, with 4 replications. The pollinators observation, as well as their identification and counting of the number of visits, occurred in the morning, during 4 consecutive days after the applications, in the flowering stage R5,5. There was no difference in richness, Apis mellifera, Trigona spinipes and Paratrigona lineata were present in all treatments, and P. lineata was the most abundant species. For A. mellifera, all pesticides had the same effect, with thin droplets resulting in lower impacts on visitation. Compared to the control, all treatments that received application were negatively affected. Unlike A. mellifera, T. spinipes was not affected by any of the factors and did not differ from the control. P. lineata presented intermediate results, varying according to the product and method of application. Results demonstrate that regardless the pesticide type, all of them can affect bees, but the method of application can minimize these effects depending on the species.