Getting the most out of your forage herbicide programs!

     County agents often get questions about herbicide control programs in forages.  Not only are herbicides expensive but your time and application costs are expensive also.   Let’s discuss some things that will hopefully make your herbicide applications more effective.

Weed Identification!  Proper weed identification is the first step when it comes to controlling weeds with herbicides.  Your local Extension agent has the resources to help you if weed identification is an issue. Cattle producers need look at their hayfields and pastures when checking on their livestock.  When you are checking livestock and scouting, make notes on locations of poisonous plants, weeds, and other things that are out of the ordinary.   Properly identifying problem weeds will make effective herbicide selection much easier.

Thistle is a common pasture weed. Make sure you properly identify weeds to select the most effective herbicide.

Herbicide Selection and Rate! Once the target weed is identified then we can select the correct herbicide and apply it at the correct rate.  Keep in mind if you apply at a lower than the recommended rate then you probably will not get the control you need, thus cost you more herbicide and application costs. If you apply above the recommended rate, then you have increased herbicide cost when compared to applying at the correct rate.

Sprayer Calibration!  It is incredible how many producers do not calibrate sprayers.  Sprayer calibration can be intimidating but if you follow the 128^th method it can be very easy. First divide 43,560 by 128.  This will give you 340.3 sq. ft. Three hundred and forty square feet is 128th of an acre.  The second step is to measure the distance between your nozzles on your sprayer in feet.  Once you figure out the nozzle distance in feet then divide 340.3 by the distance of your nozzle spacing. The result is your calibration distance in feet.  When you know your calibration distance, then mark the distance with something easy to see - such as flags or buckets.   Once the distance is marked, then have someone drive the sprayer and time the amount of time it takes to drive the distance.  Do this step a couple of times and try to simulate the same field conditions that you are applying the pesticide.  Remember do not put a pesticide in the tank during the calibration process especially when you catch the water at the end.  Once you know the calibration time, then turn the sprayer on at the same pressure and rpm as you would when you apply the pesticide but remain still so you can catch the liquid with a container. Once you catch the water, measure the amount caught in ounces. When you use the 128^th method the ounces of liquid caught equals gallons per acre.  When you calibrate your sprayer check all nozzles, hoses, and screens for wear and tear.

Weed Sizes! A smaller weed is easier to kill than a large weed. Look on your herbicide label for proper weed sizes and timings for your particular pest you are trying to control.

Other Thoughts on weed control!  The first thing producers need to do is to read the herbicide label.  It is a source of all kinds of information such as herbicide rates, water volumes needed during application and weed sizes. The label is the law. Sprayer cleanout is important especially if you use your sprayer for applying pesticides to row crops and vegetables after using with pasture herbicides. The herbicide label will have the cleanout information. Pay attention to herbicide rotation restrictions especially if you want to use clovers in your forage program. Also, if you have clovers in your forage program then that will limit your herbicide options.  Make sure you are keeping good pesticide records.   If you have any questions about herbicides contact your local county Extension agent.  You can also following this link to more information on weed management http://www.caes.uga.edu/commodities/fieldcrops/forages/pestmgmt.html.

Jeremy M. Kichler

UGA Cooperative Extension – Macon County CEC