Soybean Replanting and Fungicide Treatments
By XB Yang, Department of Plant Pathology
Integrated Crop Management News
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Late May Weather: A Mixed Message
Iowa weather during the last week of May behaved like, well, Iowa spring weather.
For the week, temperatures statewide were close to or slightly below long-term averages, and soil temperatures were general for rapid growth and development of both corn and soybean.
In addition, sporadic rains from “dust settlers” to “goose drowners” led to lots of variability in crop progress, with only a day or two suitable for field work; some areas of northwest and west central Iowa being the exceptions where more work time was available.
How Late Can Soybeans be Planted?
By Palle Pedersen, Department of Agronomy
Whether we like it,or not, there are many areas in Iowa where farmers are still waiting to plant soybeans and now, given the recent weather, many fields are going to need to be replanted. Based on the May 25 estimates from USDA, only 72 percent of our soybean acres were planted compared 80 percent last year. Bottom line: we can continue to plant soybeans until early July but a few management practices may need to be changed.
Effect of Flooding on Emerged Soybeans
By Palle Pedersen, Department of Agronomy
The excessive amount of rainfall that we have received in Iowa over the last 2 months, and particularly the last week, has caused excessive flooding in many areas. River bottoms are completely flooded and will probably not be able to be planted now for the next 2 to 3 weeks or at all this year. For the majority of the fields the water should drain and dry quickly, barring no more excessive rainfall.
Soybean Replant Decisions from Hail Damage and Flooded Fields
By Palle Pedersen, Department of Agronomy
After talking to many agronomists and farmers around the state today (May 30) it seems that many will have to replant a few fields because of the extensive rainfall that we have received over the last week. Looking at the weather forecast for Iowa today, it just does not seem to give us any relief with chances of rain pretty much every day during the next week.
Replanting Corn – How Do You Get Rid of the Existing Stand?
By Mike Owen, Department of Agronomy
The recent deluge of water has destroyed many corn fields and if the previously applied herbicide requires that corn be replanted, how do you kill the existing poor stand?
If the corn hybrid was a known herbicide resistant cultivar, your options are somewhat limited. If the hybrid was Roundup Ready®, the use of Liberty® or paraquat are not likely to consistently control the emerged corn.
Replant Options in Corn Fields
By Mike Owen, Department of Agronomy
Given the recent bad weather, it is likely that a number of corn fields will be considered for replanting to soybean. However, before this is considered, two things must be resolved; first, how will you remove the existing corn stand and second, was there a residual herbicide treatment applied to the corn?
Flooded Corn and Saturated Soils
By Roger Elmore and Lori Abendroth, Department of Agronomy
The storms last Sunday, May 25, and again on the May 29 and 30 have unloaded extraordinary amounts of rain in many parts of Iowa. Soils in the majority of the state are likely saturated. Low lying areas of fields whether they are tiled or not, are covered with ponds and areas along streams and rivers are flooded. It is not an attractive sight for producers!
Now Grow! (No, Not You, Weeds)
The week of May 19 through May 26 was slightly cooler than average. Favorable field conditions allowed corn and soybean planting to catch up. About 60 to 70 percent of soybeans are planted statewide.
Timeliness Critical to Protect Corn Yields
By Bob Hartzler, Department of Agronomy
Weeds likely are emerging with corn in many fields due to the lack of a preemergence herbicide. Whether this was planned or due to weather constraints, it is critical to control weeds early in order to protect yields.