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.

Increased Dicamba Use Requires Enhanced Stewardship

November 15, 2016

The EPA recently approved a new, low-volatile dicamba formulation - M1768 (XtendimaxTM with VaporGripTM Technology) for dicamba-resistant soybean cultivars.  While we recognize the benefit this technology provides in managing the growing herbicide resistance problem, we have concerns regarding the risks for non-target plant injury associated with an anticipated expanded use of dicamba.

What’s the Situation with SCN in Your Fields?

October 31, 2016
SCN in fields map

The soybean cyst nematode (SCN) is capable of causing serious yield loss on soybeans every year. Back in the “good ole days,” a farmer was “good to go” with SCN management if he or she knew what fields were infested with the nematode and then grew SCN-resistant soybean varieties in rotation with the nonhost crop corn. Nowadays, things are more complicated. SCN numbers may be building up and causing increased yield loss and the buildup can go unrecognized because a soybean crop often does not appear stressed above ground, even though yield loss is occurring. This article explains why this SCN numbers might be building up in your fields and how to check.

High Yields, Low Grain Prices: Manage Phosphorus and Potassium Wisely

October 21, 2016
Phosphorus and Potassium results graph

Bumper grain yields are being harvested from most Iowa fields this fall. However, due to low crop prices producers are thinking of reducing phosphorus (P) and potassium (K) fertilizer application rates. A few important management options should be considered when making decisions with unfavorable crop/fertilizer price ratios.

Cereal Rye Suitability for Roller Crimping and No-till Applications

October 19, 2016
Roller crimper photo

This time of year brings harvest, preparations for winter, and the planting of cover crops. Cereal rye is a popular and versatile cover crop that is planted in the fall and terminated in the spring. Traditional termination methods include chemicals, mowing, tilling, and even crimping prior to planting of the row crop. The roller crimper, originally designed by the Rodale Institute, is used to crimp the cereal rye stem in several places (Fig. 1). The flattened rye can create a mulch bed on top of the soil.

2016 Harvest Grain Quality Update

October 19, 2016
Dewpoint Temperatures graph

Iowa has had relief from the constant, late-September rains that were setting up for a difficult harvest season. As a result, the average grain moisture has fallen to a more typical 18-21%; lower in areas of lesser rainfall and vice versa. The potential for field drydown normally declines rapidly after mid-October. The issues of field mold that we reported in late September remain but shouldn’t be intensifying. Overall, the storage properties of 2016 will be average or below average, especially in wetter areas.

More SCN-Resistant Soybean Varieties Than Ever, but Diversity of Resistance is Lacking

October 18, 2016
Article on SCN-resistant soybean varieties

Nearly 40 years after its discovery in the upper Midwest, the soybean cyst nematode (SCN) continues to be a highly damaging pathogen of soybeans in Iowa and surrounding soybean-producing states. SCN is most damaging in hot, dry growing seasons, but yield losses of 10% to 25% or more can occur in years when temperatures are moderate and rainfall is average or above average. Growing SCN-resistant soybean varieties can slow the build-up of SCN population densities (numbers) in the soil and produce profitable soybean yields in SCN-infested fields.

Clean Combines to Avoid Weed Seed Contamination Across Fields

September 27, 2016
Weed Seed Trail from combine image

Removing biomaterial to avoid moving weed seeds between fields can be a daunting task. Typically, combines hold 125-150 lbs of grain and biomaterial after the unloading auger has operated “empty” for one minute. A true clean-out requires about six hours to remove as much biomaterial as possible. While a thorough, top-to-bottom cleaning of the combine is best to avoid the spread of weed seeds between fields, spending 15 to 30 minutes cleaning the combine before moving it out of the field will still remove some biomaterial.

Consider Combine Adjustment for Wet Field Conditions

September 27, 2016
Harvesting corn image

Coarse grains such as corn and soybeans usually thresh relatively easily, but wet field conditions may slow field drying. Rotor speed should not be increased and concave clearance should not be decreased more than necessary for threshing, but spongy corncobs or damp soybean pods may be more difficult to thresh. Greater rotor speed or reduced concave clearance may be necessary in these conditions.