Retention phenomenon from saturating plant leaves with agricultural liquids
A simple handheld field tool called an immersion cell was designed and developed to pursue studies of liquid formulation retention effects with plant leaves. The immersion protocol is one in which a finite leaf disk area is covered with a volume of a liquid formulation. A decanting process removes liquid that is classed as runoff. By measuring the runoff volume and comparing it to the original, the maximum liquid retention is obtained. Field studies were carried out to provide data for quantitative analysis. Four types of plants and three different liquid formulations were subjected to the immersion-retention study. Statistical analysis revealed a wide variety of retention phenomena. The analysis permitted a comparison of retention among the four type plants subjected to the three formulations, and separately for both sides of the leaves. Using a standard protocol, tap water was found to have the highest retention potential (mL/cm2) among the formulations on plant species studied. This was true for both the top and bottom of all type plant leaves. Field evidence was established that inducing drought-stress in cotton increased the retention forces that bind an aerial applied danitol/orthene insecticide spray formulation to the leaf surface. This response was anticipated on the basis of early exploratory studies of the retention effects. This research provides a technique/protocol for making a basic measurement regarding the retention forces that interface a liquid formulation with a plant leaf surface.