Wednesday, May 31, 2017
How to improve spray coverage and efficacy.
How to improve spray coverage and efficacy. In modern crop production systems, spraying pesticides is an essential tool in managing insects and diseases. Even with advanced integrated pest management practices and bio-controls, sprays are sometimes necessary to prevent epidemics. Whether using organic, bio-derived pesticides or conventional, chemical sprays, spray applications rarely achieve 100% control. However, increasing spray efficacy from 90–95% can have a huge effect and prevent uncontrollable outbreaks. Sprays can be expensive and maximizing value is essential,thus there are a few basic rules to keep in mind that will ensure the best possible outcome. 1) Adjust pH of Spray Solution Many pesticides/ fungicides/ herbicides perform best in an acidic solution, but ground water quality is often alkaline or neutral, depending on location of water source and time of season. Acidifying spray solutions is one step that can usually improve spray performance and is often skipped by farmers. There are several buffer solutions which are available and can be used to adjust pH of spray solution. Always consult the product label before adjusting pH, optimum pH can vary. This can be especially important with organic/ microbial-based pesticides which can drastically look efficacy if proper pH balance is not maintained. 2) Adjust to the Weather High wind speeds are obvious to avoid, but even lower wind speeds can create drift and need to be calibrated to. Temperature has a large effect on drift as well. Typically higher temps create more drift as well. Adjust height and pressure to accommodate for wind and temperature. 3) The most common failures of sprays is because spray nozzles are clogged and often need cleaning or replacing,so it is important to check every time a spray application is used. The nozzles need to be calibrated to achieve proper coverage, and speed of the tractor needs to be tested and adjusted. The easiest way to check spray coverage is by using water sensitive spray cards which can be placed at several points through the crop. more