Winter Weed Removal
The holiday season often signifies the end of our growing season for many field grown crops. Most summer crops will soon be harvested, winter crops are being planted, and farm operations are slowing down a bit as they prepare for the next growing season. During this transition, an often overlooked step growers should consider adding to their management strategy in preparation for the next growing season is destroying and/or removal of winter weeds not only in the field areas, but around borders and structures such as light poles and fence posts as well.
Many insect pests that growers combat every growing season use these weeds to overwinter and survive until spring. By eliminating the weeds these insects use to overwinter, you can greatly reduce crop damaging insect populations seen throughout the next growing season. Tobacco thrips, which often overwinter in weeds such as chickweed, knotweed, and henbit, are forced to migrate to new hosts as these plants die in the early summer. These insects often use tobacco as a host and can transmit Tomato Spotted Wilt Virus (TSWV) to tobacco plants soon after transplant. This can cause tobacco plants to develop improperly and eventually die. TSWV is sporadic from year to year depending on location and timing of thrips flights, but the disease can lead to large yield losses across fields if the particular field has a large population of tobacco thrips. Removal of winter weeds in and around fields, especially in areas where TSWV has been an issue in the past, can help alleviate many issues associated with tobacco thrips.
Foliar feeding insects are not the only pests that benefit from winter weeds. Soybean cyst nematode can use winter weeds such as Henbit as an alternate host, allowing populations to build up in the soil throughout what should be a relatively dormant time for the pest. Likewise, cutworms can use many weed species to build populations that can destroy emerging corn and soybean crops. This is just a few examples out of hundreds of insects that have a negative impact on agriculture in our area.
Winter weeds can tie up as much as 13% of available moisture, as well as nutrients that could have otherwise provided an initial boost to emerging crops, making it even more worthwhile to take control of winter annuals. Consider tillage, fall burndown or cover crops to destroy weeds and reduce next season’s weed seed bank. Weed removal and destruction is a simple yet vital tool for any grower to use for pest management and improve yields.