Weed Control in Nursery Field Production, EM 8899-E (Oregon State University Extension Service)

eld to prepare for planting, while the tractor and crew on the right are planting trees. This method provides a weed-free soil immediately after planting for preemergence herbicide applications. W eeds reduce the value of nursery crops. They compete with crops for nutrients, light, and water. Some vine weeds climb nursery crops, requiring excessive labor for hand removal. Most serious are perennial weeds, which can be harvested with nursery crops and infest the fi eld or landscape where they are subsequently planted. For these reasons, effective weed control is important for producing high-quality, marketable crops. This publication describes how to develop a weed management program in three phases: fi eld preparation, weed prevention, and management of escaped weeds. Field preparation begins several weeks prior to planting the nursery crop. Use the following steps to prepare the fi eld for planting. 1. Kill existing weeds with glyphosate. 2. Allow 1 to 2 weeks for the weeds to die, and then disk or till them into the soil. 3. Wait another 2 to 3 weeks to allow for new weed germination. This waiting period is a good time to apply preplant fertilizer and soil amendments. 4. Before weeds grow more than 1 to 2 inches, disk or till the fi eld again to kill germinated weeds and prepare the soil for planting (Figure 1). 5. Plant the crop into weed-free soil.