Integrated Crop Management News

Links to these articles are strongly encouraged. Articles may be republished without further permission if published as written and if credit is given to the author, Integrated Crop Management News, and Iowa State University Extension and Outreach. If articles are used in any other manner, permission from the author is required.

Corn Grain Dry Down in Field From Maturity to Harvest

September 20, 2017

Corn harvest is fast approaching. This year’s corn maturity is about 5-10 days behind normal. With field dry down occurring in late September and October this year, there is the potential for a later harvest of corn at a higher moisture content. The rule of thumb has been that corn dries at a rate of 0.5 to 1.0% per day in September, 0.25 to 0.5% per day in October, and almost no drying occurring in November. Of course, these rules of thumb can change with favorable or unfavorable weather conditions.

How Fast do Soybeans Dry Down in the Field?

September 19, 2017

Soybean are nearing maturity across Iowa with minimal delay due to cool temperatures compared to 2016. However, soybean sensitivity to day length speeds up crop development towards physiological maturity. During senescence carbohydrates are converted into oils. Soybean seed moisture changes very little, remaining near 60 percent during the de-greening period. As the pods turn to mature color at the beginning of maturity stage (R7), seed dry matter accumulation is complete and seed moisture rapidly decreases.

Nitrogen Considerations with Dry Conditions in 2017

August 28, 2017

The dry conditions in some areas of Iowa in 2017 have raised several soil fertility questions. In some cases, there has been relatively normal crop production and no need for management changes. In other situations with severely damaged crops, there is potential for adjustments for the 2018 corn crop.

Hessian Fly Management in Iowa

August 25, 2017
Hessian fly

With some farmers gaining interest in using cover crops, there are questions about possible pests that may develop when introducing new plants on the farm. Consider these insect-related issues when planting crops in the fall. Hessian fly (Photo 1) is a potentially destructive pest in winter wheat; however, cultural control can minimize the potential damage and economic loss.

Combine Settings for Variable Crop Conditions

August 25, 2017
Combine harvest

Although generally good, corn and soybean crops are quite variable across Iowa as harvest season approaches. Spotty rainfall, in many cases too little but in a few cases too much, along with sandy or clay soil spots, and temperature extremes or storms have resulted in varying ear, and bean pod and stalk sizes, both among nearby fields and in some cases within fields or even individual rows. Such variations put a premium on combine adjustment this fall.

How Drought Affects Soil Health

August 23, 2017
figure 1

Drought conditions during most of the growing season in Iowa can have a profound impact on soil heath, just as when we have extreme wet conditions. The effect of drought can be noticed very clearly on crop performance when the lack of water availability is severe. This water stress can affect soil chemical, physical, and biological activities that are essential for plant and soil health.

Estimating Corn Yields Using Yield Components

August 21, 2017

It’s that time of year when corn yield estimations increase. The USDA NASS objective yield survey came out on August 17. This report indicates the third highest yield on record (behind 2016 and 2015) at 188 bushels per acre. Moderate to severe drought conditions are undoubtedly the cause for the reduced yields in Iowa this year. It should be expected that there will be large variation in yield within fields but also from one field to the next depending on hybrid selection, date of planting, and field uniformity.

Phosphorus, Potassium, and pH Management Following Drought Affected Crops

August 18, 2017

Dry conditions this summer in some parts of Iowa will result in low and variable crop yield. Low or variable crop growth and yield significantly affect phosphorus (P) and potassium (K) uptake and removal with harvest. If dry conditions continue into the fall soil sampling season soil-test P, K, and pH results also may be affected complicating test interpretations.

Add Osceola County to the Map – Increased Vigilance Needed

August 16, 2017

A farmer in Osceola County recently found a single Palmer amaranth in a soybean field. He removed and burned the offending plant. This brings the ‘official’ ISU count of infested counties to 50. As we’ve stressed before, Palmer amaranth is likely in many more counties than reported to us.

Dicamba Off-target Injury Update

August 2, 2017

As of July 20, the Iowa Department of Agriculture and Land Stewardship (IDALS) had received 142 cases of pesticide misuse, historically this number has ranged from 58-85 at this time of year. Dicamba was involved in 46 of these cases. Two of the dicamba cases involved use in non-crop areas, 10 involved applications on corn and 36 were related to applications to dicamba-resistant soybean (Xtend). The soybean cases were nearly evenly split between Xtendimax w/VGT and Engenia, there were no reports involving products not registered for use on soybean. Cases a

Pages