Integrated Pest Management of Sunflower Insects
This is the first in a series of articles addressing the concept of Integrated Pest Management (IPM) of insects in sunflower. This introductory article addresses some of the currently used terms for agricultural production systems or approaches (e.g., “sustainable agriculture”); the topic of IPM; what it means; and what relevance it holds for sunflower production.
Subsequent articles — beginning with the December 1995 issue of The Sunflower and continuing through the April/May 1996 issue — will discuss separate aspects of IPM. Among them will be: (1) pest identification, economic thresholds and monitoring of fields; (2) biological control action (action of parasites, predators and diseases); (3) plant resistance; (4) cultural control (planting date, tillage, plant population, etc.); and (5) chemical control.
Insects are part of our world and share the environment. They have been very successful, are more diverse than any other plant or animal group — and they exist everywhere.
That “everywhere” includes in our agricultural crops. In the natural environ-ment, insects usually are held in check by a variety of forces, including their natural enemies. Agricultural crops, on the other hand, are artificial environments and thus need constant maintenance.
Fortunately, only a very small percentage of insects actually are economic pests. Many insects are beneficial, serving as either pollinators or natural enemies of other insects. The natural enemies, by and large, keep the others from becoming significant pests.
Insects become pests when their populations grow — usually as a result of something we humans have done. Planting large monocultures or acreages of one crop, for example, provides an excellent food source that allows certain insects to increase their numbers. Since those insects have become our competitors, we must do something to reduce their densities so that producing a crop is profitable. Most of the time, this means killing the insects.
So why do we need to concern ourselves with managing pests? Why can’t we just destroy them and forget about compli-cated and time-consuming strategies as we work to keep them from damaging crops?
There was a time, shortly after the development of synthetic pesticides in the late 1940s, when some people thought all insect pests could be killed by the new insecticides and thereby become extinct. Scientists and agricultural producers soon realized, however, that some insects became resistant to the chemicals that were applied to destroy them. More-frequent applica-tions and higher doses were required to achieve the same amount of control.
Also, a new problem often arose. Insects that had not been a problem before suddenly were causing economic damage. This unpleasant development was due to the destruction of natural enemies (parasites and predators) which previously had been feeding on those insects and preventing them from achieving the status of “economic pest.”
Today, there also are health and environmental concerns stemming from the overuse or long-term use of pesticides. The desire to have agricultural production that is “sustainable” also has increased the need for pest management strategies which minimize economic, health and environ-mental risks. The need for a variety of approaches to pest management — though certainly complicating the work of the grower — has become necessary due to both practical and environmental concerns.
One of the things the scientific community does well is to come up with terms. Many have been coined for a variety of agricultural production systems. Among them are: organic agriculture, alternative agriculture, low-input agricul-ture, low-input sustainable agriculture (LISA), ecological agriculture and sustainable agriculture.
While “organic agriculture” seeks to eliminate synthetic chemical-based management practices, “LISA” has the goal of reducing the application of purchased inputs — and thus is more economically focused. (Continued on Page 16)
“Sustainable agriculture” is defined as an integrated system of production practices that are site-specific and, over the long term, will satisfy food and fiber needs, enhance environmental quality, make the most of nonrenewable resources, integrate natural biological cycles and control, sustain the economic viability of farm operations — and enhance the quality of life. The idea is to meet the needs of the present without compromising the ability of future generations to meet their own needs.
Stewardship of both natural and human resources is cited as being of prime importance.
The goals of sustainable agriculture — environmentally sound, socially acceptable, economically viable — are certainly valid; but the term cannot be permanently defined: What’s “sustainable” today might not be tomorrow. Research enabling us to move in this direction needs to be long-term, large-scale and integrative from all disciplines.
key element in moving toward the goal of sustainability is the use of Integrated Pest Management. An increased national focus on IPM is evolving, since the Clinton Administration committed itself to helping agricultural producers implement this approach on 75 percent of total crop acreage by the year 2000. Last December, USDA announced an “IPM Initiative” to provide farmers with the new tools they need, through research and education, to move toward this goal and to deal with the environmental and economic challenges into the 21st century.
Integrated Pest Management is an ecologically based pest control strategy that is part of the overall crop production system. Different ways of controlling pests have been used for centuries; but the idea of combining various methods into an integrated system dates from the 1950s.
IPM is integrated because it incorporates all appropriate methods from many scientific disciplines into a systematic approach to optimize pest control. All available management decisions or options are considered — including that of taking no action at all. Knowledge about the pest is required, as are established economic or treatment thresholds and the results of field monitoring to determine whether the pest has reached the threshold.
Control tactics with IPM include such techniques as cultural control (crop rotation, tillage, planting dates, field sanitation); use of resistant plant varieties; biological control (introduction of new natural enemies, conservation of natural enemies, mass release of natural enemies); and insecticidal control (synthetic-organic pesticides, pathogens, nematodes).
IPM involves maximum reliance upon natural pest population control, along with the other tactics which may contribute to suppression of the pest. Chemical pesticides are used only when necessary.
From this list of tactics, it is obvious that prior planning is critical to effective pest management — i.e., a number of the techniques must be put into effect prior to the crop going in the soil.
Evidence from numerous efforts to incorporate IPM into major crops around the United States shows that, when adopted, IPM results in economic benefit to both the agricultural producer and society at large — typically accompanied by a reduction in pesticide use.
IPM of insects in sunflower is now being utilized, and research is continuing in the development of additional tactics. When-ever crops are rotated or planting dates altered to avoid synchronizing crop development to times when plants ar most susceptible to pests, IPM is being utilized. Producers who monitor the pest density in their fields and treat with pesticides only when the economic threshold has been reached also are practicing IPM.
Implementing IPM does take more effort and knowledge, but it will be beneficial in the long term. Research and extension personnel are well aware of the importance of IPM and are willing to assist in developing the best management strategies possible. Doing so is in the best interest of all of us.
As one writer recently remarked, “Everyone wants a quick fix, but there are no silver bullets.” There are only good farming practices using all available resources. The goals are clean water, environmental safety and reduced pesticides in foods. IPM is the way to move toward these goals; and while it may not be the only avenue, it certainly is an essential one.
As mentioned earlier in this article, future articles in The Sunflower will discuss many of the key elements and methods forming the basis of Integrated Pest Management and how they relate to sunflower production specifically.
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