The University of Minnesota's Southwest Research and Outreach Center (SWROC) held its annual winter crops and soils day event Feb. 1. A broad number of topics were covered, but one theme loomed large across the entire day – how the low price of corn and soybeans is impacting area farmers.

How and when to market crops was discussed; along with high input costs such as seed, diesel fuel and fertilizer. Land rent, arguably the largest cost, was discussed as well.

With razor-thin margins on profit and loss, farmers need to be aware of all the factors going into either a good crop, or a so-so crop.

That’s why Jim Kurle, Department of Plant Pathology, University of Minnesota, St. Paul gave a talk on soybean seed, seedling and root rots. Kurle said these rot issues, if left unchecked, can impact a farm’s profitability heavily.

“Phytophthora root and stem rot is problematic,” Kurle said. “It is widespread in soybean producing areas across the U.S., and worldwide. In north central U.S., it is the second most damaging resulting in a yield loss of 42.2 million bushels alone in 1998.”

Kurle said in Minnesota, phytophthora is responsible for yield losses approximately around 1 percent, but under the right conditions those losses can reach as high as 6 percent.

“Even worse, on an individual field basis, if it takes hold, losses of 50 to 60 percent have been seen,” Kurle added.

Kurle also discussed the issue of pythium blight. Pythium-induced root rot is another common crop disease. When the organism kills newly emerged or emerging seedlings, it is known as damping off, and is a very common problem in fields.

Damping off is a horticultural disease or condition, caused by a number of different pathogens that kill or weaken seeds or seedlings before or after they germinate. 

It is most prevalent in wet and cool conditions, such as we have during early spring in southwest Minnesota. Both phytophthora and pythium have some common triggers in Minnesota.

“Their affect is very sensitive to environment,” Kurle said. “In particular the environment we confront in Minnesota – cold, wet, early springs. We see losses of up to 6 percent annually due to these (fungi). The point to make is they are very sensitive to environmental factors. Some years they are unimportant. Other years, they can be very serious.”

Cost and profitability are also very serious factors to considered.

“Seed is becoming a larger and larger input cost,” Kurle said. “When you are looking at upwards of $60 per acre for seed, in an environment where seed and seedlings are being challenged, this is important. Earlier and earlier planting is being encouraged, and this is on top of an emerging weather pattern where we have a warm up, then followed by (it is followed by) cold, wet soils consistently in the spring. Combine that with changes in management practices – minimum to no tillage, high residue delays the soil warming up – and prolongs the cold, moist soil conditions.”

Ways of dealing with these conditions include adequate crop rotations, reducing soil compaction, good soil drainage and tillage.

In addition, planting resistant cultivars, partially resistant cultivars and using chemical treatments like metalaxyl, mefanoxan and ethaboxam can help.

“The problem is, these pathogens that are most damaging to soybeans, are found on corn, too,” Kurle said. “We have a situation where we don’t have any rotation choices. In terms of this pathogen, we're not planting in a rotation with corn and soybeans. We are planting in continuous cropping that is allows pythium to develop.”

Sudden death syndrome (SDS – fusarium virguliforme) is another soybean/corn crossover causing alarm.

“I would argue for more diversity in our cropping system,” Kurle said. “I think what we are running into is the limitation of the corn and soybean rotation. I don't have any solid evidence for it, but SDS turned up across the state in very short order. There is evidence it is growing on corn grain and corn residue. Then the right environmental conditions come along and it explodes. This is going to be problematic moving forward as farmers, who aren’t making money on corn, will plant more and more soybeans if they want to stay in business. There are no magic bullets here to take care of the problem. It is going to have to be good practices combined with resistant seed and adequate treatments.”

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