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.

2015 Evaluation of Foliar Fungicides on Corn at Four Iowa Locations

June 1, 2016
Evaluation of Foliar Fungicides at several sites

Every year we evaluate commercial fungicides on corn applied at V5 alone, VT-R1 alone, or both growth stages for disease control and effect on yield. The trial was done in collaboration with the farm managers at four Iowa State University (ISU) Research and Demonstration Farms (Table 1). The trials are laid out in a randomized complete block design with four to six replicates.  Plot sizes are 10 foot (4 rows) wide and 30-100 foot long. Hybrids varied by location.

Stalk Borers Moving in Southern Iowa

May 31, 2016
Stalk Borer photo

Tracking degree days is a useful tool to estimate when common stalk borer larvae begin moving into cornfields from their overwintering hosts. Foliar applications, if needed, are only effective when larvae are migrating and exposed. Start scouting corn for larvae when 1,300-1,400 degree days (base 41°F) have accumulated. Southern Iowa counties reached this important temperature benchmark over the holiday weekend (Fig. 1), and therefore scouting for migrating larvae should begin now to make timely treatment decisions.

Aphids Showing Up in Alfalfa

May 17, 2016
Pea aphid photo

Aphids are common insects to see in field crops, especially in alfalfa. In Iowa, there are at least four aphid species that can persist on alfalfa. A recent report of pea aphids near Clarion, IA from field agronomist Angie Rieck-Hinz prompted me to write this article. Learning to distinguish aphids in alfalfa takes a little practice, but is worth knowing for making sound treatment decisions.

Spring Seedling Sampling

May 3, 2016
Spring Seedlings for testing

Seedling diseases could be an obstacle for farmers this year with the early planting of corn and soybean. While we all hope that seedling diseases will be a small consideration, it is important to be ready for them. It is also important to know how to sample for them.

Black Cutworm Scouting Advisory 2016

May 3, 2016
BCW Cutting Estimates 2016

The black cutworm (BCW) is a migratory pest that cuts and feeds on early vegetative-stage corn. Black cutworm moths arrive in Iowa with spring storms each year. These moths lay eggs in and around fields and the emerging BCW larvae cut seedling corn. The sporadic nature of this pest makes scouting essential to determine if management is needed. Scouting for BCW larvae helps to determine if an insecticide application will be cost effective.

Don't Forget SCN Sampling on Your List of Spring Chores

April 15, 2016
Areas of a field where SCNs are most likely to be found

A simple but potentially valuable spring task to consider is sampling fields for the soybean cyst nematode. And since we are heading into the cropping season, it makes sense that attention be given to those fields in which soybeans will be grown in 2016.

Look for Seedcorn Maggot in Corn and Soybean

April 13, 2016
Seedcorn maggot and larva

Seedcorn maggot is a seed and seedling pest of corn and soybean. Plant injury is especially prevalent during cool and wet springs. The larvae, or maggots, feed on germinating corn and soybean seeds or seedlings (Photo 1). They can feed on the embryo, delay development or kill the plant. Infestations tend to be field-wide instead of grouped together like for many other pests. To confirm seedcorn maggot injury, check field areas with stand loss and look for maggots, pupae and damaged seeds (e.g., hollowed out seeds or poorly developing seedlings).

Soil Health Benefits for Sustaining Crop Production

April 13, 2016
No-till corn system

The benefits of healthy soil in sustaining crop production are most evident when growing conditions are less than ideal. Healthy soils increase the capacity of crops to withstand weather variability, including short term extreme precipitation events and intra-seasonal drought. The extreme drought in 2012 resulted in variable yield reduction to corn and soybean production in Iowa with the worst impact on fields with conventional tillage systems (i.e., chisel plow, deep ripping, etc.).