Soggy conditions may damage beans
Wet conditions are all too familiar to Jefferson County farmers with the exception of last year, when 2012 was classified as a drought.
“Before last year, we had two or three years of wet field conditions also,” said Nancy Parsons at Reiff Grain & Feed in Fairfield.
“All of Iowa had 85 percent of corn planted as of last week, and I’d say of the farmers who come through here, 98 to 99 percent have their corn planted,” said Parsons. “Some have barely started on soybeans, others may have half their beans planted and some may have all of their beans planted.”
Beans have not emerged yet and the rain brings concerns of dampening off and seed damage to beans, Parsons said.
“Beans can suffer seed rotting because they’ve been totally saturated with water in the ground,” said Parsons. “A lot of fungal diseases are caused by wet conditions. Beans with seed treatments on them should be OK.”
For the corn, nitrogen leaching is more of a concern.
“Too much water in the soil causes nitrogen, which is the primary nutrient for growing corn, to move further down into the soil and the corn’s roots can’t access it,” said Parsons. “This may require farmers to apply nitrogen or side dress the crops.”
Saturday is the federal crop insurance deadline for preventive planting, said Mark Carlton, crop specialist at Iowa State Extension Service based in Monroe County.
“After June 1, farmers don’t have to plant corn, their crop insurance policy kicks in,” said Carlton. “It’s estimated for every day after June 1 that corn is planted, it loses 1 percent in yield.
“Farmers need to re-examine their needs and contact their insurance specialist for details about their plans. I’d say if a farmer is going to plant corn after this, it would be OK for chopping [for feeding livestock] but strictly as a grain farmer, it’s best to check with the insurance.
“And at this point, I wouldn’t plant corn shorter than 105-day corn,” said Carlton.
June 15 is the federal crop insurance deadline for preventive planting for soybeans, he said.
“It’s going to be a week to 10 days of no rain before farmers can return to the fields,” said Carlton.
Iowa Secretary of Agriculture Bill Northey’s weekly report at the beginning of this week said dry conditions the previous week gave farmers some planting time. According to the USDA, National Agricultural Statistics Service, 85 percent of Iowa’s corn acreage has been planted. That is still behind the five-year average of 98 percent for the state at this time of the season.
The state’s corn crop is 54 percent emerged, which is well behind 2012’s rate of 93 percent and the average 81 percent emergence for this time of year.
Soybean planting in Iowa was 40 percent complete, compared to 95 percent last year and the 83 percent five-year average. Soybeans showed an 8 percent emergence rate overall in Iowa.
“The wet weather continues to slow planting progress as farmers remain well behind five year averages for both corn and soybean planting progress,” Northey said earlier this week.
On the other hand, recent wet weather has converted last year's drought in Iowa to flooding across much of the state.
The latest U.S. Drought Monitor report released Thursday says only about 2 percent of Iowa was experiencing moderate drought this week and 17 percent of the state was abnormally dry.
The National Drought Mitigation Center at the University of Nebraska-Lincoln uses data from Tuesday morning for its weekly updates. Several rounds of storms have dumped rain on Iowa since then, so the remaining dryness in northwest Iowa may have already been eliminated.
Wet field conditions could be infecting soybeans now with Sudden Death Syndrome but it won’t be recognizable until later in the summer, perhaps in July.
According to a 2010 article published by Integrated Crop Management News and Iowa State University Extension, “Sudden Death Syndrome in soybeans is caused by a fungus present in many Iowa soils that infects soybean roots and produces a toxin that moves up the plant and kills the leaves. It is not the result of any single factor.”
The article, written by Alison Robertson, assistant professor of plant pathology with research and extension responsibilities in field crop diseases and Leonor Leandro, assistant professor of plant pathology with research and teaching responsibilities, stated:
“There has been a gradual buildup of SDS in Iowa over the past 10 years. Temperatures below 60 at planting favor infection of soybean roots by the SDS fungus. However, greenhouse research has shown that infection can occur at temperatures up to 82.
“Moderate temperatures, about 80 degrees, during the growing season leads to SDS symptoms developing on the leaves. Wet weather and soil compaction favor SDS disease development.”
The article said sudden death syndrome does not occur on corn, but research at Iowa State University revealed that the SDS fungus survives on corn kernels and other corn debris.
Information from the Associated Press was used in this story.