Intermittent chemical applicator for renovation of strawberries

A chemical applicator for renovation of strawberries was designed and constructed. Outputs of even spray nozzles spaced 8 inches apart were directed through ports alternately opened and closed by solenoid actuated gates for intervals corresponding to 16 inches of ground travel. Ports along the boom were alternately opened and closed, creating a grid pattern of sprayed and unsprayed matted-row vegetation. Formulation collected when a given port was closed was returned to the tank for recirculation.

In addition to design and construction of the applicator, the study objectives included evaluation of the precision of the grid pattern of sprayed areas produced by the machine. Colored water was applied on white crate paper at three operating speeds using the chemical applicator. Two series of tests were conducted on smooth operating surfaces, and one series was conducted on a bump track.

Data were collected by measuring the sprayed areas of each intermittent spray pattern track. There were approximately seven patterns created by each nozzle from each of these seven patterns. Variation of sprayed areas among treatments (speeds) and among nozzles was determined using these data.

Applicator modification was needed after the first smooth surface test, due to indicated excessive variation among nozzles. After completing modifications there was no significant variation among treatments (speeds) or among nozzles with either the second smooth operating surface or the rough operating surface test.