Weeds

Part 2, Section 5: Small Grains Pest Management

Small Grains Pest Management

A well-planned pest management program for small grains involves using multiple strategies. These should include preventive techniques such as monitoring, cultural controls, mechanical or physical controls, biological controls, and chemical control tactics. Preventive techniques may start with planting weed-free crop seed or choosing an alternative field or planting date. Regularly monitoring for pests is an important predictive tool. Rotating crops to disrupt pest life cycles and planting adapted varieties are good examples of cultural controls. Mechanical or physical controls may include tillage and mowing to disrupt certain pests. Biological controls may include using insect or disease organisms or even grazing animals in pasture production systems. Finally, chemical controls are an important component of many IPM systems, but their use should be based on sound management decisions. See Part 2, Section 1 of this guide for more information about designing an integrated pest management program.

This guide provides chemical control suggestions based on university research and manufacturer recommendations. Management information for common small grain pest problems is outlined in the following pages under “Weeds,” “Insects,” and “Diseases.” For more information on small grain management and variety selection, see Part 1, Section 7. This publication strives for accuracy; however, omissions, inaccuracies, or dated information can occur because of the dynamics of pests and pest management. Seek out additional information from the manufacturer or other reliable sources when making important management decisions. Remember, this guide is not a substitute for the manufacturer’s product label.

WEEDS

A good small-grain stand is highly competitive and usually does not require herbicide treatments to control weeds. The foundation of the weed-control program should be proper planting of an adapted variety at recommended populations. Winter annuals such as chickweed and henbit are becoming more common in small-grain fields.

Fields should be scouted in late fall or early spring to determine if populations warrant treatment. Early application while weeds are still small is the key to successful control of weeds in small grains. Apply herbicides only at recommended stages of crop growth in order to avoid crop injury. See Figure 2.5-1 and Tables 2.5-1 to 2.5-6.

Oats, barley, and wheat are sensitive to triazine residues; therefore, use a short residual herbicide program when small grains follow in the crop rotation. Read the corn weed-control section (Part 2, Section 2) for information on the effect of pH on triazine residues, and for weed-control programs that reduce triazine residues.