Planting Issues


Every year brings unique pest challenges. Many early planted fields have been replanted or are in the process of being replanted. This year, soybeans seem to be more at risk than corn and the culprit is seed corn maggot. If your soybean stands appear to be thinner then normal and patchy, seed corn maggot may be the issue if planted early and the seed sat in cold wet soils for long periods before germinating. With good growing conditions, soybeans usually outgrow seed corn maggot damage.

Scouting some fields, I found in drilled 7” soybeans, gaps that ranged from 1-3 feet. Most of the damage had been done so there was no soybean seed to be found. Due to the earlier dry weather conditions, followed by rain, it appeared that soybean seed that was planted deeper and in moisture, germinated and outgrew most damage. Shallow planted soybeans seemed to be the most at risk. Seed corn maggot flies are attracted to decaying organic matter where they lay their eggs. While it was dry early in April, the cold May rains slowed down germination and plant growth.

Most of the seed applied insecticides especially the neonicotinoids (Cruiser, Poncho, Gaucho) did not work very well this year. Treated seeds were damaged because the insecticide is water soluble and may not be around when the pests show up because it had already washed away. In one corn study, only 2% of these insecticides were around when the pests showed up. In wet saturated soils, the insecticide which becomes water soluble. Making matters worse, the neonicotinoids are quite deadly to many natural predators. Other seed treatment alternatives to the neonicotinoids are Capture, Force, Lorsban, and Counter.

At what point do you replant soybeans? Most farmers are planting 180-200 thousand seeds per acre. An OSU university study found that soybeans at 85-100 thousand seeds can yield as much as the higher soybean populations. The caveat is that the plants have to be evenly spaced in the field so that the soybeans plants can branch out. Most farmers have insurance for free replant. With large gaps or patchiness, replanting is a safe bet. Once soybeans have at least 1-2 trifoliate leaves, they can tolerate replanting as long as they are not completely cut off. As with the lost art of rotary hoeing, you will lose some but hope to gain more than you lose.

There are several other issues I observed this year. After digging a soil pit, our subsoil moisture in Northwest Ohio appears to be very dry. Several farmers digging several pits have noticed that once you get below 6-8 inches deep, the soil is very dry. Let’s hope we continue to get some consistent soft gentle rains to restore our subsoil moisture. If it gets hot and dry this summer, our subsoil moisture reserve appears to be very low.

With a lot of wheat planted this year due to higher prices, some weed issues are showing up. Cereal rye is becoming a weed in some wheat fields. Sometimes farmers will spread the cereal rye with fertilizer and/or use the same spreaders to spread fertilizer on wheat. Sometimes not all the cereal rye gets terminated in soybeans, and if this cereal rye goes to seed, it can become a weed in wheat fields. There is no easy way to get rid of cereal rye rouge plants. Cereal rye is usually about 1-2 feet taller than the wheat and the seed matures about the same time as wheat. The cereal rye seeds become foreign matter in harvested wheat and the miller’s despise cereal rye in flour. Keep cool and enjoy the summer! 

Another issue that is occurring on some fields are slugs and voles, although major damage seems to be either in isolated fields or around field edges, especially when close to tall growing vegetation. Voles or field mice can migrate 2 miles each way so when they find a field they like, they tend to stay until the food source is gone, then they move somewhere else. Both slugs and voles prefer wet conditions and young lush slow growing vegetation. Fields that have a lot of unharvested seed on the soil surface (corn, soybeans, wheat, rye seed, or weeds) and high vegetation (weeds or thick cover crops) tend to have more slugs and voles. Keeping fields mowed down so predators can get these pests help. Rotary hoeing to disturb and dry out vegetation and 10” high steel post bird perches have been helpful.