Timely scouting and strategic crop rotation can help optimize kochia control as part of an integrated weed management program.
Long stretches of warm temperatures in February have spurred kochia seedlings to start emerging in parts of the midwest including western Nebraska. Since control of kochia seedlings is best shortly after emergence, scouting now will help alert growers about whether they need to spray for it. Rodrigo Werle, a cropping systems specialist at the University of Nebraska, recommends taking advantage of the early warm temperatures we are experiencing to spray for kochia when the plants are most vulnerable to herbicide application. Werle says that waiting to control kochia until close to crop planting typically does not yield satisfactory results – control is most effective on small, newly emerged plants. Since kochia may continue to emerge in several spurts throughout the spring, periodic timely scouting as the spring progresses will help growers manage kochia prior to planting.
A diverse crop rotation may also help optimize management of kochia as part of an integrated program, because it increases the diversity of effective herbicide options available to the grower. Because glyphosate-resistant kochia is widespread in Nebraska, Werle emphasizes the importance of using multiple effective herbicide modes of action to manage it and not relying too heavily on glyphosate alone. This helps prevent selection of glyphosate-resistant populations in the field and targets the infestation from multiple angles. Diversifying the herbicide program from year to year in a crop rotation can help increase the number of effective modes of action used.
Werle recommends the following herbicide options for early season kochia management:
- Before corn: Burndown – glyphosate, dicamba, 2,4-D, paraquat and/or glufosinate. Soil residuals – atrazine, isoxaflutole, mesotrione, saflufenacil, flumiozaxin, and/or pyroxasulfone.
- Before soybeans: Burndown products – glyphosate, 2,4-D, paraquat and/or glufosinate. Soil residuals – metribuzin, sulfentrazone, flumiozaxin, saflufenacil, and/or pyroxasulfone.
- Under fallow: Burndown – glyphosate, dicamba, 2,4-D, paraquat and/or glufosinate. Soil residual product(s) such as atrazine, metribuzin, isoxaflutole, and/or sulfentrazone.
- In winter wheat: Post-emergence products – 2,4-D, dicamba, fluroxypyr, pyrasulfotole + bromoxynil, carfentrazone-ethyl, prosulfuron, metsulfuron, and/or triasulfuron.
Read the full story here by Rodrigo Werle, University of Nebraska.