The Effectiveness of the Application of a Chemical Agent (Dressing) to Seed Potatoes by Means of an Innovative Valve Enabling Intermittent Flow of a Liquid

Abstract

The protection of potatoes from pests and diseases, especially at an early stage of their development, is an indispensable element of cultivation. Pesticides are most commonly used for protection, but their high doses may adversely affect the natural environment, including soil and water. This study compares the losses of a chemical agent emitted during the dressing of seed potatoes by means of an innovative valve enabling intermittent outflow of the liquid and by means of a standard valve with a continuous outflow. The research proved that the intermittent outflow of the working liquid decreased the amount of the chemical agent emitted into the environment ten times. The article also describes the site at which the innovative valve was tested and compares the results of laboratory tests for three distances of the sprayer from the potato fall path (50, 100, 150 mm) and four different pressures of the working liquid (1-4 kPa). The research showed that the amount of losses, i.e., emissions of the chemical agent into the environment from the innovative valve (intermittent stream of the working liquid) depended on the difference in the air and liquid pressure. The solution is environmentally friendly. The results showed that the distance between the sprayer valve and the seed potato falling path had minimal influence on the amount of the agent left on the surface of seed potatoes when a continuous stream was applied, but it had considerable influence when an intermittent stream was applied. The distance had negative effect on the ratio of retention of the applied liquid at pressures of 100 and 200 kPa, but it had positive effect at pressures of 300 and 400 kPa (at an intermittent flow). When a continuous stream was applied and the distance between the spray valve and the seed potato falling path increased from 100 to 150 mm, it had positive effect on the retention coefficient for all the four pressures tested (100, 200, 300, 400 kPa).