When it comes to controlling weeds in pastures and hayfields, several tools may be needed to achieve success. The best defense against weeds is a good, dense stand of grass or forage. There are several things to help us succeed in weed control management.
The first thing is to perform a soil test. With fertilizer prices at an all-time high, this will help determine what nutrients are needed to produce that dense stand of forage. Soil fertility is important because soils are the basis of everything we do agronomically. Soil is the basis for lawns, gardens, pastures, hay meadows and livestock, to name a few.
The second thing is to determine what weed species are present. Are the weeds annual, biennial or perennial? This is important because not all weeds are created equal. Different weeds are controlled at various stages of growth and development. Annuals are easily controlled at the seedling stage while perennials are controlled at the flowering and flowering stage. Biennials are controlled at the rosette stage.
Using selective pesticides to control unwanted vegetation in pastures or hayfields can be part of the process. Many farmers and ranchers today incorporate integrated pest management into their weed control arsenal.
A common question that many ask is how much pesticide do I add to the sprayer tank? It’s a good question, but there are some things we need to know first. Do you know how much your sprayer produces? Sprayer calibration can help us answer many questions.
So how do I calibrate my sprayer? First, do you have a boom or boomless sprayer? For a boom sprayer, determine nozzle spacing. We have documents with recommended nozzle spacing and calibration run lengths. For example, if the nozzle spacing is 24 inches, the course will be 170 feet long. If the nozzle spacing is 32 inches, the run would be 127 feet long.
For a boom sprayer, measure and stake the appropriate calibration run based on the nozzle spacing. The course must be on the same type of ground that will be sprayed. Speed is important, so use conditions similar to spraying. Drive the course in the speed and rpm you will use when spraying. Record the time in seconds and do it several times on the course to get an average. Park the tractor and maintain the same rpm. Turn on the sprayer to pick up water from the nozzle for the same number of seconds it took to travel the course. Ounces captured equal gallons per acre.
For a sprayer without a boom, measure the effective swath width. For example, a 35 foot swath uses a calibration run of 157 feet. For a 45 foot swath, use a calibration run of 121 feet. Follow the same instructions as mentioned above for a boom sprayer by running the course recording the time in seconds.
Turn on the sprayers and use a bucket that will fit over the group nozzle as it is important to catch all the water during the seconds you have been on the course. Pints caught equal gallons per acre.
Once we have determined what our sprayer produces at different speeds and in different terrains, we can then determine how much product to add to the spray tank. This is important for achieving effective control and using pesticides according to label directions and application rates. Underapplication or overapplication can be a problem when using pesticides for weed control.
— Shaniqua Davis is the Agriculture and Natural Resources Extension Officer for Gregg County. Email: [email protected]