By Blake Jackson
Kochia, a tough and fast-growing weed, has been found in soybean fields in northwestern Missouri. This is the first time it has been spotted in Missouri croplands, raising concerns among researchers and farmers alike.
Wayne Flanary from the University of Missouri Extension confirmed the presence of kochia in Atchison County soybean fields. Although kochia has existed in Missouri, this marks its first appearance in active cropland.
This weed can reduce crop yields by up to 70%. It grows aggressively, competes with crops for sunlight, water, and nutrients, and can reach six feet tall. It is also drought-tolerant and produces up to 30,000 seeds per plant. With the right conditions, kochia seeds germinate in just two to three hours.
A major concern is that kochia may be herbicide-resistant. MU weed scientist Kevin Bradley noted, “Growers should keep in mind that they may already be dealing with a population that is resistant to glyphosate or perhaps some other herbicide.”
In states like Kansas, Nebraska, and the Dakotas, kochia is already a major issue, with some populations resistant to triazines, glyphosate, and even dicamba.
Kochia likely entered Missouri cropland through floodwaters from the Missouri River. Once mature, the plant becomes a tumbleweed, spreading seeds as it rolls across fields.
To manage kochia:
- Rotate crops regularly
- Use fall cover crops and tillage to disrupt early growth
- Apply pre-emergence herbicides in late fall or early spring
- Kill small weeds early
- Destroy the plant before it flowers to prevent seed spread
Bradley recommends spot spraying or hand removal of plants. Timely action is key to limiting kochia’s spread and protecting soybean yields.
Photo Credit: university-of-missouri
Categories: Missouri, Crops, Corn, Soybeans