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.

New Dicamba Labels Limit Application Timing

October 25, 2017
graph showing available spraying hours per day

The EPA recently announced changes to the new dicamba labels in response to widespread off-target plant injury in 2017.  The most significant change is classification of the new dicamba formulations as Restricted Use Products. Other changes will reduce the hours available to spray soybean, including 1) restricting applications to between sunrise and sunset, and 2) reducing the maximum wind speed during application from 15 mph to 10 mph. The ability to cover all acres in a timely manner has always been an issue and these new limits will add to that difficulty.

Sampling for Nematodes that Feed on Corn Not Advised in the Fall

October 21, 2017
small corn seedling lying on shovel blade, collected to test for damaging levels of nematodes

Recently there have been many questions about how to check fields for plant-parasitic nematodes that can damage corn. Unfortunately, the situation cannot be accurately assessed with samples collected in the fall. This article discusses when and how to sample for plant-parasitic nematodes that feed on corn.

A Guide to Choosing Corn Hybrids

October 9, 2017

When you think about which hybrids to plant next season, make sure to take into account all the relevant factors. When selecting hybrids, prioritize yield potential and risk management. There are a number of other components to consider as well, including transgenic options, disease tolerance, maturity, grain dry down, standability, stalk quality, and early season vigor ratings.

What to Look For in Choosing Soybean Varieties

October 3, 2017

When looking for soybean varieties, it is important to give as much thought to the process as you give to choosing corn hybrids. If you only choose one or two soybean varieties and do not take into consideration management and environmental factors of your operation, you are likely limiting yield potential.

Fall Marestail (Horseweed) Management

October 2, 2017

Marestail (Conyza canadensis) is one of the most difficult weeds to manage in no-till soybean.  While classified as a winter annual, the plant has significant emergence in both late summer/early fall and in the spring.  This extended emergence period greatly complicates management since the success of postemergence products is closely tied to plant size.  Attempting to control populations at the time of planting often results in control failures as fall-emerged plants are too large for acceptable control.

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.