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Seed treatments abound

We talked last month about choosing hybrids and varieties to plant — a daunting task by itself. To add to the challenge, you also get to pick from among many different seed treatments.

Not that long ago, the decisions were pretty simple: Seed corn came pretreated, and we had limited options for soybean seed. There isn’t room in this article to list the many seed treatment products on the market today, but the number is in the dozens.

If you plan to purchase some “high-value” soybean varieties and corn hybrids, the choice is still simple — they are sold pretreated with a combination of products. But the majority of seed products come with many options, forcing you to make some tough choices and do some hard thinking.

Early-season stresses

Each year, weather permitting, you work to plant corn and soybean fields as early as possible. While this early planting typically puts you in the best position to maximize yields, it can also expose crops to early-season stresses. This is where seed treatments have the opportunity to shine.

The primary role of seed treatments is to improve stand establishment and overall plant health by curbing the effects of early-season diseases and insects. Because there are too many individual products to go into detail on each one, let’s talk about the main categories of seed treatments.

Fungicides: Seed-applied fungicides suppress stand-reducing diseases. Length of protection and spectrum of diseases suppressed varies with products and application rates.

Prime candidates for fungicide seed treatments include no-till and reduced-till fields; early-planted fields; fields planted corn on corn or beans on beans; fields with cool or wet soils, or other conditions that may slow germination; and fields with a history of seedling diseases.

Work with your seed supplier to match the right fungicides to the disease problems you may encounter.

Insecticides: These treatments help battle early-season insects that can impact stands and even plant health. Again, length and spectrum of control depend on product and rate used.

Most insecticide seed treatments are meant to control early-season insects that attack seedling corn and soybean plants. However, a few are designed to work longer into the season, such as those targeting corn rootworms.

Another treatment being studied to offer longer-term control is integrating soybean aphid-resistant beans with a seed-applied insecticide to fight soybean aphids throughout the season.

As with fungicide seed treatments, fields likely to benefit from an insecticide seed treatment include early-planted fields, fields under no-till or reduced till, and those with conditions that may slow germination such as cool or wet soils, as well as fields with a history of early-season insect pests. Work with your seed dealer to match the right insecticides to the insect problems you may encounter.

Nematicides: Within the next year or two, farmers will have the opportunity to battle corn nematodes, and possibly soybean cyst nematodes, with seed-applied nematicides.

This emerging technology offers a chance to fight corn nematodes, a pest for which we currently have no good management options. In the battle against soybean cyst nematodes, while there is a lot of work to be done, the emergence of products like these may offer added firepower to supplement SCN-resistant soybean varieties. Sampling soil for nematodes is a great first step in knowing how well such products will fit your acres.

Besides these three main categories, there are other seed treatments to consider as well. Inoculants, growth promoters and other amendments are becoming more available, adding to the difficulty in determining what you may or may not need.

No easy answers

While the choice is rarely easy, selecting the right seed treatments may prove worth the effort. Because they are applied to the seed in anticipation of problems, seed treatments offer risk management.

Understanding and discussing the challenges your crops may face with your seed professionals will help them understand your individual needs and help you sort through the myriad of seed treatments available, to fit products to your fields and each year’s weather conditions.

With all that said, I agree, there are still no easy answers to the question: “What treatments should I put on my seed?” Each of us has to evaluate our situation and risk management strategies. The good news is there is no shortage of products to help fight whatever crop culprits you are facing.

McGrath is the partner program manager and Extension agronomist for ISU’s Corn and Soybean Initiative.

This article published in the January, 2010 edition of WALLACES FARMER.

All rights reserved. Copyright Farm Progress Cos. 2010.