Agriculture

Wed
20
May

2020 scouting recommendations for black cutworm


Figure 1. Estimated black cutworm dates for each Iowa crop reporting district based on peak flights during April.

Figure 2. Black cutworm larvae have grainy and light grey to black skin. Photo by Adam Sisson.

Figure 3. Black cutworm (left) can be distinguished from other larvae, such as dingy cutworm (right), by the dark tubercles along their bodies. For black cutworm, the tubercles nearest the head on each segment are about 1/3 the size of the tubercle closest to the rear. Corresponding tubercles on dingy cutworm are about the same size. Photos by Adam Sisson.

Figure 4. Black cutworm is known for completely severing corn seedlings. However, injury from black cutworm larvae usually begins above the soil surface. Leaf feeding can occur (left), or larvae can severely damage or kill plants (right). Photo on left copyright Marlin Rice; photo on right courtesy of Jon Kiel.

by Ashley Dean, extension program specialist, Erin Hodgson, associate professor, Integrated Crop Management News, and Iowa State University Extension and Outreach

Black cutworm (BCW) is a migratory pest that arrives in Iowa with spring storms each year. BCW moths lay eggs in and near crop fields, and larvae can cut corn seedlings or feed on leaves. Even though crops were planted earlier this year than previous years, cold temperatures may slow growth and allow BCW larvae to coincide with early vegetative corn that is vulnerable to BCW injury.

Wed
13
May

What's Up at the USDA Office?

Upcoming Deadlines/Dates
May 15 - August 1: Primary Nesting Season - No MCM work on CRP acres
June 30: 2020 ARCPLC Election
July 15: Crop Certification
September 30: PLC Yield Update

May 2020 FSFL Interest Rates
New rates were issued for the month of May and are as follows:
• 0.250% for 3 years
• 0.375% for 5 years
• 0.625% for 7 years
• 0.750% for 10 years
• 0.750% for 12 years
• 0.875% for 15 years

Wed
13
May

Alfalfa weevils active throughout Iowa


Figure 1. Accumulated growing degree days (base 48°F) in Iowa from January 1 – May 2, 2020. Map courtesy of Iowa Environmental Mesonet, ISU Department of Agronomy.

Photo 1. Mature alfalfa weevil larvae have a dark head and pale green body with a white stripe down the back. Fully-grown larvae are about 5/16 inches long. Photo by John Obermeyer, Purdue University Extension.

Photo 2. Alfalfa weevil adults have an elongated snout and elbowed antennae. Their wings and body are mottled or brown. Photo by Clemson University – USDA Cooperative Extension Slide Series, Bugwood.org.

Photo 3. Heavily-defoliated alfalfa fields appear frosted from a distance. Photo by Whitney Cranshaw, Colorado State University, ipmimages.org.

Table 1. Economic threshold of alfalfa weevil, based on the average number of larvae in a 30-stem sample (Originally published by John Tooker, Penn State Extension). For more information on how to interpret the table, visit https://crops.extension.iastate.edu/explanation-updated-threshold-table-alfalfa-weevil.

by Erin Hodgson, associate professor, Ashley Dean, extension program specialist, Integrated Crop Management News, and Iowa State University Extension and Outreach

Adult alfalfa weevils become active and start laying eggs as soon as temperatures exceed 48°F. Like other insects, the development of alfalfa weevil depends on temperature and we can rely on the accumulation of growing degree days (GDD) to predict activity. Alfalfa weevil egg hatching begins when 200-300 degree days have accumulated since January 1.

Based on accumulated temperatures since January, alfalfa weevils may be active in much of the state (Figure 1). Some areas in northern Iowa have lower GDD accumulation and may not see activity yet. In Iowa, fields south of Interstate 80 should be scouted beginning at 200 GDD and fields north of Interstate 80 should be scouted beginning at 250 GDD.

Wed
13
May

SWCD coordinates soil health project through Regional Conservation Partnership Program

The Allamakee SWCD is coordinating a project through the Regional Conservation Partnership Program (RCPP), a program funded through the USDA. The practices funded through this project are:

1. Cover crops on manure applied acres
2. Cropland conversion to hay/pasture (and all related practices including fencing, watering systems, prescribed grazing, and heavy use protection)
3. Adding a small grain to a rotation
4. Utilizing cover crops as part of a 3-crop system (corn-soybean-small grain)

Only a fraction of conventional row crop farmers grow cover crops after harvest, but a new global analysis from the University of Illinois shows the practice can boost soil microbial abundance by 27%.There are many benefits to planting cover crops including reducing erosion, increasing organic matter, reducing compaction, improving nutrient cycling, and providing food for beneficial soil microorganisms.

Wed
06
May

What's Up at the USDA Office?

Upcoming Deadlines/Dates
May 15 – August 1: Primary Nesting Season – No MCM work on CRP acres
June 30: 2020 ARCPLC Election
July 15: Crop Certification
September 30: PLC Yield Update

2020 Crop Certification
The on-going COVID19 situation has changed the way we operate at the office.  We are doing much more through phone and email.  Unfortunately, at this time, it appears we will not be able to certify crops face-to-face at the office.  While the final details are still being decided, it looks like we will be mailing out farm maps to the operator for them to mark the crops planted, date planted, and shares.  Then return them to us via mail, email or the drop-box outside the office.  We would then load them and determine the best way for you to sign the certification whether via mail, email, or drop box. Our goal is to start getting maps mailed out the week of May 11.

Wed
06
May

Mild winter favors bean leaf beetle survival


Photo 1. Adult bean leaf beetle. By Winston Beck.

Figure 1. Predicted overwintering mortality of bean leaf beetle based on accumulated subfreezing temperatures during the winter (1 October 2019 – 15 April 2020).

Figure 2. Predicted bean leaf beetle mortality by year for central Iowa; the red line indicates the average mortality rate (71%).

by Erin Hodgson, associate professor, Ashley Dean, extension program specialist, Integrated Crop Management News and Iowa State University Extension and Outreach

Bean leaf beetle adults (Photo 1) are susceptible to cold weather and most die when air temperatures fall below 14°F (-10°C). However, they have adapted to winter by protecting themselves under plant debris and loose soil. Each spring, adult beetles emerge from their overwintering habitat and migrate to available hosts, such as alfalfa, tick trefoil, and various clovers. As the season progresses, bean leaf beetles move to soybean and other hosts. While adult activity can begin before soybean emergence, peak abundance often coincides with early-vegetative soybean.

Wed
06
May

Seedcorn maggots flying in Iowa


Photo 1. Typical seedcorn maggot injury in soybean (Submitted photo by Marlin Rice) and corn. Submitted photo by Purdue Extension.

Figure 1. Degree days accumulated (base 39°F) for seedcorn maggot in Iowa (January 1 – April 15, 2020). Map courtesy of Iowa Environmental Mesonet, ISU Department of Agronomy.

Photo 2. Seedcorn maggot (left) and pupae. Photo by Brian Lang, Iowa State University.

Photo 3. Seedcorn maggot adult is a small, grey fly. Photo by www.ipmimages.org.

by Erin Hodgson, associate professor, Integrated Crop Management News, and Iowa State University Extension and Outreach

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). Feeding can delay development or kill the plant. Infestations tend to be field-wide instead of in patches like for many other pests. To confirm seedcorn maggot injury, check field areas with stand loss and look for maggots, pupae and damaged seeds (hollowed out seeds or poorly developing seedlings).

Wed
29
Apr

What's Up at the USDA Office?

Upcoming Deadlines/Dates
May 15 – August 1: Primary Nesting Season – No MCM work on CRP acres
June 30: 2020 ARCPLC Election
July 15: Crop Certification
September 30: PLC Yield Update

Sign Up for the 2020 ARCPLC Program by June 30!
Producers can enroll in the Agriculture Risk Coverage (ARC) and Price Loss Coverage (PLC) programs for the 2020 crop year. Many got this completed during the recent 2019 signup, however there are still many farms that need to get enrolled. 

ARC provides income support payments on historical base acres when actual crop revenue declines below a specified guaranteed level. PLC provides income support payments on historical base acres when the effective price for a covered commodity falls below its reference price.

Wed
29
Apr

Pros and cons of reemergence herbicide application timings


Waterhemp escapes in crop row due to preemergence herbicide being moved by row cleaners. Submitted photo.

by Bob Hartzler, professor of agronomy, Meaghan Anderson, field agronomist and extension field specialist, Prashant Jha, associate professor and extension weed specialist, Integrated Crop Management News, and Iowa State University Extension and Outreach

Preemergence herbicides are the foundation of herbicide-based weed management systems, and effective use of these products is essential to protect crop yields and reduce selection pressure for herbicide resistant weeds. In a perfect world, applying preemergence herbicides immediately after planting would provide the greatest likelihood of maximum performance, but equipment and labor availability limit many farms from using this approach. This article will provide a brief overview of the pros and cons of different application strategies.

Wed
29
Apr

Allamakee County Soil and Water Conservation District awarded grant funding for cover crop interseeding project

We are excited to announce that the Allamakee County Soil and Water Conservation District has been awarded $235,907.00, for a three-year project, that involves interseeding cover crops into V4-V7 Corn. The funding for this project came from the USDA Conservation Innovation Grant (CIG) program.

Short planting windows after commodity crop harvest has some producers frustrated and looking at other methods of getting cover crops established. One option is interseeding cover crops into corn between the V4-V7 growth stages. Doing this allows cover crops to get established prior to corn canopy.  After canopy the cover crop will go dormant from being shaded out and then restart growth once the corn is harvested. The overall goal of this project is to get more producers to try interseeding as an option for cover crop establishment.

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