Evaluation of spray drift in potatoes using various spray delivery systems

Abstract

Spray deposition has previously been studied within a potato canopy In a followup study spray drift was evaluated using three treatments from the previous research plus two treatments encompassing an additional grower standard and a spray drift standard Treatments included (1) an airassisted Gambetti sprayer with fullcone nozzles applying spray at a rate of 400 litres/ha (2) a rotary atomizer spraying system (Proptec) applying spray at a rate of 200 litres/ha (3) a dropleg application spraying above (25) and below canopy (75) at 260 litres/ha (4) a conventional hydraulic nozzle spray boom with Guardian AIRtrade; Twin nozzles applying 200 litres/ha and (5) a conventional hydraulic nozzle spray boom with standard 11003 nozzles at 300 litres/ha Data were normalized per nozzle and application rate (200 litres /ha) With the exception of the Gambetti application results indicated a similar pattern with very low deposition beyond 10 m downwind The Gambetti results showed very low deposition near 0 m and spray cloud reaching 40 m but it is believed that the turbulent airflow from the Gambetti sprayer adversely affected the deposition samplers through a high level of disturbance so more data are necessary for further analysis of this effect