Sustainable Practices for Vegetable Production in the South
Dr. Mary Peet, NCSU
Home

Integrated Pest Management

INTRODUCTION

Integrated pest management (IPM) is a set of practices designed to avoid economic losses from pests while at the same time minimizing use of pesticides or other practices with possible detrimental effects. over the past 20 years, there has been a steady increase in the use of IPM due to increased public emphasis on environmental safety, development of pest resistance to all the major classes of insecticides and a reduction in the number of new insecticides, but only in the past five years has there been a dramatic move to IPM in agriculture.

Individually, IPM practices are not very different from practices used in conventional pest control. Collectively, however, they represent a very different management philosophy. A successful IPM program considers the effect of every aspect of farm management on pest and beneficial populations. Plowing, crop scheduling, irrigation and mulch application may be adjusted to reduce future pest problems.

For example, an IPM practitioner might consider the following: Nitrogen fertilizer has stimulated aphid outbreaks in cole crops; insecticides may kill natural enemies of weeds; fungicides may kill soil microorganisms that control nematodes; and both insecticides and fungicides may reduce earthworm populations, thus lowering soil fertility and water infiltration rates.

Managing crops to reduce buildup of pest populations is an important component of IPM programs. Crop rotation is one of the best ways to avoid pests. Rotation with cover crops, grains, and vegetables in different families from the crop is probably the most effective way to prevent buildup of insects, diseases, and weeds. The greater the differences between plants in rotation, the more effective they are in suppressing pest populations. For example, alternating upright crops, such as tomatoes and peppers which are widely spaced in rows with crops such as leafy greens which are planted densely on beds will interrupt weed life cycles, as will alternating between cool and warm season crops.

To the extent that crop rotation improves soil structure and fertility, crops grown in rotations should also be better able to tolerate or outgrow pest damage. For example, alternating between shallow- and deep-rooted crops improves air infiltration to the soil and increases water availability.

Although rotation will almost always offer some reduction in pest problems when compared to continuous cropping, it is most effective in reducing pests with a narrow host range and those that cannot survive more than one or two years without a host. Rotation is of little help with highly mobile insects.

While we usually think of IPM in relation to insect pests, IPM principles also apply to weed and disease control. The essential components of an IPM program are:

1. Scouting, monitoring and sampling to identify pests and estimate their populations. The successful practitioner must know when and how to sample and how much crop damage current pest populations will cause if uncontrolled.

2. Knowing whether the amount of damage predicted will reduce net returns, that is, whether damage exceeds the economic injury threshold. The economic threshold is the point at which the predicted dollar value of losses from pest damage exceeds the cost of control.

3. Determining the best control or management strategy when predicted damage exceeds the economic threshold. If it is not possible to reduce insect, disease, or weed levels below the economic threshold or at least to acceptable levels in the current growing season, practices such as crop rotation are implemented to prevent problems in subsequent seasons.

• INSECT MANAGEMENT
• DISEASE MANAGEMENT
• NEMATODE MANAGEMENT
• WEED MANAGEMENT

References

• Marrone, P.G. 1994. Present and future use of the Baccillus thuringiensis in integrated pest management systems: an industrial perspective. Biocontrol Science and Technology 4:517-526.

• Luna, J.M. and G.J. House. 1990. Pest management in sustainable agricultural systems. IN C.A. Edwards, R.Lal, P. Madden, R.H. Miller and G. House, eds. Sustainable Agricultural Systems. Soil and Water Conservation Society, Ankeny, IA.

• Flint, M.L. 1989. Pests of the garden and small farm. Univ. of California Statewide IPM Project Publication. 3332.

• Wintersteen, W.K., and L.G. Higley. 1993. Advancing IPM systems in corn and beans. p. 9-32. IN A.R. Leslie and G.W. Cuperus (ed.) Successful implementation of integrated pest management for agricultural crops. Lewis Publishers. 193 p.

Move directly to: Table of Contents

Last Modified: Thursday, October 4, 2001