Theses and Dissertations
Issuing Body
Mississippi State University
Advisor
Chesser, Gary D.
Committee Member
Lowe, John W.
Committee Member
Reynolds, Daniel B.
Date of Degree
12-10-2021
Document Type
Graduate Thesis - Open Access
Major
Engineering Technology
Degree Name
Doctor of Philosophy (Ph.D)
College
College of Agriculture and Life Sciences
Department
College of Agriculture and Life Sciences
Abstract
Variable-rate technologies coupled with broadcast spray systems serve to reduce chemical inputs, misapplication of chemicals, and environmental pollution, thus improving profitability and sustainability. Sprayer variable rate control involves using pulse width modulation (PWM) solenoids and/or direct chemical injection to adjust the application rate. The objectives of this research were to: outfit a conventional broadcast sprayer with PWM and direct inject technologies; evaluate the accuracy of the PWM system to control application rate for strait line and turn segments; and characterize the direct injection system’s transport delay time. For the PWM evaluation, the mean flow rate and coefficient of variation of individual nozzles indicated consistent performance. For the direct injection evaluation, the manufacturer recommended plumbing scheme and injection point location resulted in unsatisfactory delay times, ranging from 105 to 150s for the 8 km h-1 (5 mph) speed and 60 to 90s for the 16 km h-1 (10 mph) speed.
Recommended Citation
Walker, William, "Evaluation of the variable rate capabilities of a sprayer equipped with pulse width modulation nozzle control and direct chemical injection systems" (2021). Theses and Dissertations. 5348.
https://scholarsjunction.msstate.edu/td/5348