Issue No. 2, Article 9/April 1, 2004
Efficient Scouting--Eight Simple Rules
One thing is for sure: The pest situation in Illinois and the Midwest is never static. Each year brings new challenges. Last season, when many of you were inundated with "new" pest situations, did you know how to make treatment decisions about them? Did you know the latest techniques for soybean aphid scouting, or when you should do something about those pesky Japanese beetles or soybean cyst nematodes? Were you confident in your field identifications of pests and beneficial organisms? Were those diseases out there or environmental problems?
Spring is here, and with the new growing season it's a sure thing that new and old pests will make themselves known. You will be able to informatively respond to developing pest situations by scouting. Scouting gives you the information you need about pest identification and population growth to make environmentally sound management decisions for your clients or your own fields.
Extension Educator Matt Montgomery and I presented a session at the 2004 Illinois Crop Protection Technology Conference on field crop scouting. What can a crop scout do to become moreefficient? The following summary from that session of eight simple rules will help you scout more efficiently.
Rule 1: Correctly identify the causal agent. This rule is really the cornerstone of any good integrated pest management program. If you don't take the time to determine the identity of the causal agent, you are wasting your time and possibly the producer's money. Incorrectly identifying or lacking identification of a causal agent in the field may lead to unnecessary use of pesticides, missed pest management opportunities, elimination of beneficial organisms, or worse. An example of how this simple rule can benefit the producer pertains to early-season cutworm observations. If observed cutworms are black cutworms, an insecticide may well benefit the producer, depending on the percentage of the plants clipped and other factors. However, if the cutworms observed are dingy cutworms, an insecticide will likely not benefit the producer. Dingy cutworms are often leaf feeders and thus tend to cause "non-economic" injury to seedling corn. An insecticide application to a dingy cutworm-infested field often results in unnecessary expenditure by the producer.
Rule 2: Understand how the environment influences a problem. The development of pest problems can be greatly influenced by environmental conditions. For example, insects such as the corn flea beetle cause more problems following mild winters when the overwintering adults survive at fairly high levels.
Rule 3: Keep up with "the latest." Resources and time are limited for all involved in agriculture, and the efficient crop scout will be the one who stays apprised of the latest pest developments and plans activities accordingly. The Field Crop Scouting Manual and periodicals represent one means by which to accomplish this feat. The Bulletin, pest management bulletins from other states, company pest bulletins, and local newsletters can provide the "bird's-eye view" of the current pest situation. Human resources can supply especially valuable information. Clients, co-workers, and others with even a basic understanding of possible field pests can provide many eyes and ears to the crop scout, alerting you to missed pest developments, accelerating problems, and true non-issues. Add some eyes and ears south of your territory, and you gain a virtual crystal ball. Since some pest problems will progress south to north, friends "down south" can warn crop scouts of problems that might be coming their way in the next few weeks.
Rule 4: Remember that beans can be "tough stuff." Soybean leaves can take a lot of punishment. Enough said.
Rule 5: Know what structures/stages you should be looking for during each crop growth stage. Following this rule requires that you know about pest life cycles and how a particular pest matures and reproduces. References such as the Field Crop Scouting Manual and the Bulletin will help tremendously.
Rule 6: Take "more than a glance." Crop scouts are often tempted to quickly glance at the end rows of a field when making pest management decisions. However, making a "good" decision requires that one take a "good" survey of the actual situation in the field. Is the pest problem limited to a few localized areas? If so, a quick survey may provide an exaggerated view of the actual situation as you stumble into a "hot spot." Likewise, a quick survey can cause you to miss a real problem if you happen to examine one of a field's few relatively healthy areas. A 2003 example of this phenomenon relates to Japanese beetle management in eastern Sangamon County. Initial "quick" observations of field edges showed very intense pressure from this silk-clipping pest, but additional "more-intense" observations showed that many of those infestations were confined to the end rows. Fertilization was inhibited in the end rows in these cases, but the interior regions of the field established kernel before beetles could inhibit that process. Producers who choose to quickly examine fields in 2004 for Japanese beetle may overestimate or underestimate the impact of this pest. Only a good, thorough survey into the field will provide an accurate picture for decision making.
Rule 7: Recognize what nature can do for you. You need to be able to recognize beneficial insect species as well as pay attention to changing local weather conditions that may be unfavorable for disease or insect development.
Rule 8: When possible, "catch it early." This one is straightforward. Maintain a regular scouting schedule so that increases or decreases in pest populations can be quickly realized. Our general recommendation of scouting a field every 7 to 10 days has everything to do with the typical life- cycles of our common field crop pests in Illinois and nothing to do with how many miles we think you should be putting on your vehicle.--Suzanne Bissonnette and Matt Montgomery