Researches regarding the reduction of pesticide soil pollution in vineyards

Abstract Phytosanitary treatments with pesticides are widely used for pest and disease control in vineyards. When performing the treatment an important part of the dispersed pesticide falls on the ground, affecting the microorganism and fauna, producing quantitative and qualitative changes in both the structure of the edaphic population and in its physiological activities. In order to diminish soil pollution experimental field tests concerning pest and disease control in vineyard were performed, using a spraying machine provided with an equipment which aims to recycle the pesticide liquid that is not retained by the vine foliar system. The equipment was built up based on a commercial TARAL 200 PITON TURBO air-assisted sprayer, used for pest and disease control in vineyards and orchards and was equipped with two recycling panels, placed on each side of the vine row. CFD simulations were used in order to optimize the dimensions, geometry and position of the recycling panels. The experiments were performed for different vegetation stages, forward speeds and operating pressures; for the first vegetation phase (bud opening), the pesticide recycled volume reached 45% of the total applied volume; in phases VI and VII the recycling rate was lower than 25%. For the vegetation phase V and for the forward speeds and operating pressures taken into account the quality of the treatment was evaluated using the mean foliar deposit. The results obtained by the means of ImageJ processing software indicated an adequate operating process of the spraying equipment; the values of this index were ranged between 21.4% and 36.2% for the upper side of the leaves and between 18.6% and 29.7% for the lower side of the leaves. The best indices were attained for low forward speed and an operating pressure of 0.6 MPa.