Anti-splash additives for reducing pollution and increasing yield with agricultural sprays

Agricultural spraying is widely employed for crop fertilizing and pest management. Recent work from our group has shown that rheologically modifying these agricultural solutions can reduce the required chemical load and subsequent impact on the environment. Specifically, adding small amounts of long-chain polymers to increase the extensional rheology can increase droplet size to reduce drifting in the wind to off-target locations, while simultaneously reducing the loss of droplets from plant surfaces due to bouncing and splashing. However, the pH and ionic strength of these agricultural solutions can vary enormously from one application to another, which presents a challenge to proper formulation.. In this talk, I will present a new method for screening additives by quantifying their effect on spray performance. Further, I will present data showing that polyethylene oxide is an excellent candidate as a polymer additive and exhibits a complex non-monotonic relationship between its performance and the pH and ionic strength of the spray solution. Also, I will present data showing that the exceedingly long molecular length of these polymers makes them susceptible to chemical and mechanical degradation that can interfere with their intended function in sprays.