Dry soil across the state has reduced the performance of preemergence herbicides. Rotary hoeing is the most cost-effective means of controlling weeds that may have escaped control from these products. Rotary hoes are most effective against weeds that have germinated but not yet emerged through the soil surface (white-root stage). Although the rotary hoe generally is used prior to crop emergence, it can still be an effective tool after the crop has emerged. When using the rotary hoe after crop emergence, it is important to monitor the crop during the operation for possible physical damage. Generally, soybeans are most susceptible to injury during the crook and cotyledon stages of growth, and injury often is more severe in the morning than the afternoon. Corn is more prone to injury when the coleoptile is just below the soil surface. Hoeing at this time may cause leafing out underground.
||An emerged velvetleaf survives rotary hoeing.
The dry soils present in much of the state have reduced weed establishment during the last 2 to 3 weeks. The recent rainfall events probably will stimulate a new flush of weeds. Although rotary hoeing probably will not eliminate established weeds, it should greatly reduce the density of weeds whose germination was stimulated by the latest rainfall events. Rotary hoeing should not significantly impact soil moisture due to the shallow depth at which this tool operates.
This article originally appeared on page 69 of the IC-484 (9) -- May 15, 2000 issue.