Experts pinpoint ways to prevent crop problems Every spring you run into a few crop-related headaches. But you can shelve the Advil by minimizing some of those early season problems. That's the word from seed company agronomists - expert troubleshooters who get called when problems pop up.
Soybean Digest asked four agronomists - from Indiana, Illinois, Wisconsin and Iowa - to discuss the most frequent problems they encounter, and how those frustrations might be avoided.
Insect injury to young corn plants has been a major problem in southeastern Indiana, reports Tony Halter, Pioneer field sales agronomist in that area.
"This is probably the result of the mild winters we have had and to some extent because of reduced tillage," says Halter. "In particular, we're having problems with such early season insects as wireworms, seed corn maggots and a virtual explosion of white grubs. For corn in the early vegetative stage to 12" tall, we've experienced concerns with stinkbugs and billbugs."
If this winter is another mild one, Halter will recommend a soil insecticide next spring - in areas with known problems - to combat seedling pests.
"Unfortunately, we don't yet have a good program for controlling stinkbugs and billbugs," he says.
Another concern is injury from soil-applied herbicides that may occur during cool, wet conditions. However, the injury usually is cosmetic and has little or no effect on final yield.
"It's often due to shallow planting," Halter points out. He advises a seeding depth of 1 1/2", both for protection from herbicides and to establish an optimum root system.
Uneven corn stands are another common problem. "We can improve stand uniformity by having the proper pressure in air planters and proper calibration on finger pickup planters," he says.
Scott Stein often deals with problems involving early corn planting. The Monsanto agronomic systems manager, based in northern Illinois, says cold, wet and compacted soils can hamper early season growth.
"Early April often brings a week of warm, sunny weather to our area," says Stein. "However, soil temperatures are still below 50 and we usually see more typical spring weather return before a planted crop emerges.
"After approximately 20 days in the soil, an unemerged corn seedling begins to lose its vigor," he notes. "The longer the germination period, the more vulnerable the seed is to soil insects, seedling blights and herbicide injury."
He lists three guidelines for growers who start early:
- Plant only those fields with excellent surface and internal drainage.
- Select a hybrid with a very strong emergence rating.
- Don't plant too shallow. It can lead to problems, especially injury from soil-applied herbicides.
"Soybean cyst nematodes have been the biggest issue in soybeans," says Stein. "Unfortunately, growers often don't realize they're present until a major yield loss occurs. The best ways to evaluate fields are to examine roots and do soil sampling."
Stein recommends that farmers be field-specific when selecting corn hybrids and soybean varieties.
"Keep a yearly history of each field, with its diseases, insects, drainage and fertility," he advises. "Then work with your seed supplier to choose the product that can best handle those situations. A written record helps get the product in the right place at planting time."
Nina Holte, area agronomist for Garst in west-central Wisconsin, had a number of calls about uneven corn emergence last spring.
"It was nearly always because of shallow planting - anywhere from only 1/2-1 1/4"," she reports. "In this area, 1 1/2-2" are ideal. We recommend that farmers continually check seed depth, particularly when soils are very mellow. Also, check seed placement every time you change soil type or where there is a different previous crop."
Holte has seen insect damage to young corn plants in recent springs.
"This is unusual for Wisconsin, and is the result of mild winters," she says. "If we have another mild winter this year, I'll recommend a seed treatment when planting corn into sod or following soybeans. I'll recommend a soil insecticide on corn after corn."
Soybeans are relatively new for some farmers in Holte's area, and there have been emergence problems.
"Usually, it's because they're planted too deep," she points out. "Typically, I like to see them at 1/2-1 1/4", unless it's sandy soil and they need to be slightly deeper to reach moisture."
Herbicide damage to corn has been getting much of Bob Streit's attention. It often can be traced to the wrong hybrid-herbicide matchup, says Streit, a Mycogen regional agronomist in central Iowa.
"I encourage farmers to become as familiar as possible with hybrid-herbicide interaction," he says. "If a farmer relies on a local chemical dealer for herbicide recommendations, he should ask if the dealer has certified crop advisor (CCA) status. That's a good indicator of his herbicide knowledge."
A number of Streit's calls have involved uneven stands. There also are complaints about poor insect and weed control.
"In most cases those problems are the result of planters or other pieces of equipment that are not in proper working condition or calibration," he says. "Farmers could prevent many of the problems by attending clinics sponsored by implement dealers on machinery maintenance and adjustment, and following the advice."
Streit frequently troubleshoots insect damage to corn, soybeans and alfalfa. He says the key to controlling insect pests is to scout each field - or hire it done - to learn what's out there.
"It's also helpful to watch the statewide entomology reports," he says. "University entomologists can usually tell you when a given insect will enter a certain area. They also will provide treatment thresholds. This information is available both on the Internet and through a pest letter subscription. It definitely pays off."