As temperatures warm, warm-season grasses and weeds will come to life, including the beautiful wildflowers.
Unfortunately, along with the good, there will also be those pesky weeds, including plants like the sandbur. Field sandbur (grassbur) is a summer annual or short-lived perennial grassy weed found in home lawns, sports fields, parks, along roadsides, and in bermudagrass pastures and hay fields. This weed is especially adapted to dry, sandy soils but can be found growing in other types of soils as well. The big problem with this weed is the sharp, spiny burs that are part of the seedhead. The bur spines are stiff and can injure the mouths of animals and the hands and feet of people working in infested crops. Field sandburs generally start germinating in spring and will continue to germinate until late summer or early fall months. This weed will continue to grow until the first hard frost or freeze occurs in the fall.
Until recently, there were few herbicide tools available to help manage the sandbur in our bermudagrass pastures. Now however, Prowl H2O, from BASF, has received a label that will allow application to dormant bermudagrass pastures and hay meadows for control of sandbur and other weed species (numerous annual grasses and small seeded broadleaf weeds), all of which are listed on the full label.
The label rates for Prowl H20 on dormant bermudagrass pastures and hay meadows is 1.1 to 4.2 quarts per acre. The higher rate is suggested for more dense infestations of targeted grasses and weeds, or where a longer duration of residual weed control is desired. The timing for application is any time during winter dormancy and prior to weed germination. Ideally, activation of this herbicide is accomplished with one inch of precipitation following application.
There are some additional restrictions, including: do not harvest bermudagrass hay until 60 days after treatment, and do not harvest for forage or allow livestock to graze until 45 days after treatment.
Prowl H20 can be used on all bermudagrass varieties, but the stand must be established and have gone through at least one cutting before treatment. The use of Prowl H20 on rangeland is prohibited.
If you miss the opportunity to treat for sandburs when the bermudagrass is dormant, there might be another option available. Pastora herbicide, from Dupont, was recently labeled for control of emerged sandburs in bermudagrass. Applications should be made to seedling sandburs (when the sandbur is less than 1.5 inches tall and/or across) and actively growing. Moreover, applications of Pastora have to be made to bermudagrass that is less than four inches tall following initial green-up in the spring or after cutting for hay. Tall, dense stands of bermudagrass can intercept spray and reduce sandbur control.
Pastora should not be applied to newly sprigged or newly planted bermudagrass. Apply only to established bermudagrass that is at least one year old. A follow-up application of Pastora may be necessary to control subsequent germination (flushes) of sandbur following the first application. For control of sandbur species, apply Pastora herbicide at a broadcast rate of 1.0 to 1.5 ounces per acre. There are no grazing or haying restrictions for this herbicide and, as always, read and follow all the label restrictions when utilizing this product.
The control of sandbur in bermudagrass pastures and hay meadows with herbicides should be part of an overall management plan that includes fertility management based on soil testing, adequate soil moisture, insect and rodent control, along with best management agronomic practices.
Any references made to commercial products or trade names were made solely for educational purposes with the understanding that no endorsement nor discrimination is implied by Texas AgriLife Extension Service or its agents.
Jeffrey Stapper is the Agricultural and Natural Resources Agent for Nueces County. Readers may contact him at (361) 767-5217.