European Corn Borer

I was called to look at some field corn in Burlington County because of insect damage. The damage was due to some significant populations of european corn borer larvae. This is not suprising given that the RCE Vegetable IPM program was reporting very high populations of adult moths in black light traps earlier this spring. Those of us in field crops tend to forget about ECB because of Bt hybrids. Remember though we can still treat for ECB in the required non-Bt refuges and non-Bt planted fields. Rescue treatments are not that effective when the larvae are deep in the whorl or in the stalk. Information on scouting and treatments for ECB can be found in the Mid-Atlantic Pest Management Recommendations for Field Crops. Keep in mind that ECB can also attack sweet corn and peppers.

Bill Bamka

Mid-Atlantic Regional Agronomist Quarterly Newsletter June 2011

Dr. Richard W. Taylor's Mid-Atlantic Regional Agronomist Quarterly Newsletter is available for download. 

Please note in the calendar of events that a number of meetings are coming up both this week and next week so check the calendar over carefully. Also feel free to forward the newsletter on to anyone else you think might be interested in the information. - R. Taylor

To subscribe, send request to: rtaylor@udel.edu

Rabin

Manganese deficiency in soybeans

Over the past few days I have begun to notice manganese deficiency appearing in some of our earlier planted soybean fields. As many of us know manganese deficiency on soybean can be a common and recurring deficiency on our sandy soils in the southern portion of the state. Deficiency results in reduced leaf chlorophyll content. The common symptom in soybeans is interveinal chlorosis (the tissue between the veins turns yellow while the veins remain green). Manganese deficiency can result in reduced yields. Extensive research by our extension soil fertility specialist Dr. Joe Heckman has shown an economic benefit of applying foliar applications of manganese fertilizer to soybeans deficient in manganese. More information is available on manganese deficiency in the RCE publication Soil Fertility Recommendations for Soybeans.

This photo shows a soybean plant with typical symptoms of manganese deficiency.


Bill Bamka

Head Scab in Wheat

I have been out in several wheat fields recently and have noticed the symptoms of head scab. This is not suprising since our region was at a high risk for developing head scab about a month ago during the warm humid weather we had.

Early Wheat Harvest/Drying

With high soybean prices this year, most wheat acreage will likely be planted to double crop soybeans. Every week's earlier planting of soybeans could mean 4 or more bushel yield increase, which could more than pay for drying wheat harvested at higher moisture. The drying characteristics of wheat are much different than corn so farmers must consider many aspects before considering early harvest of wheat in the next few weeks. A fact sheet from the University of Kentucky has some specific details that is a must read if early harvest and drying will be considered.

Zane R. Helsel

Grasshoppers

I am starting to get reports of grasshoppers in some early planted soybean fields. We are starting to see this now that rye is being harvested. Some of these soybean fields can be susceptible to feeding from grasshoppers. The feeding can result in stand loss. When stand losses occurr from emergence to the second trifoliate a treatment might be necessary. It is difficult to find exact treatment thresholds for grasshoppers. Guidelines often used for treatment are 30% or more defoliation with one or more grasshoppers per sweep with a net. It is generally not too difficult to tell if grasshoppers are abundant, so don't worry if you do not have a net. This guideline is used from emergence to the pre-bloom stage. Many times grasshoppers are concentrated along field edges or ditches, so it may be possible to only treat the areas where grasshoppers are found.

Bill Bamka

Pest Alert: European Corn Borer (ECB) in Sweet Corn

For more than a decade, a general decline in ECB adult moth populations and larval infestation rates have been seen in most crops. Generally entomologists in the eastern US are attributing this long decline in ECB to increased production of Bt field corn which would be a dead end host for the pest. An adult moth population bucking this trend is widely observed this spring 2011. The reasons are unclear but it is a fact. Growers are advised to scout all whorl and pre-tassel fields.

Two New Sources of Information about BMSB

The Brown Marmorated Stink Bug is expected to inflict serious crop damage again this year. Brown Marmorated Stink Bug has a wide host range including soybean and field corn. Two new sources providing timely information about this pest can be found on the Brown Marmorated Stink Bug page, Rutgers NJAES Snyder Research & Extension Farm Website. 

• IPM Update: BMSB Activity for the Week Ending May 23, 2011. Kris Holmstrom, Vegetable IPM Program, has reported the first capture data of the season in the Plant & Pest Advisory.
• Penn State Extension has gathered information about the Brown Marmorated Stink Bug in a special issue of the Fruit Times.

-Rabin

Sidedress Nitrogen on Corn?

Late April /early May planted corn is now reaching the growth stage V-6 ( 6 fully developed leaves-canopy about 12-18 inches high) where the crop begins to take up significant amounts of Nitrogen(N) which is critical to reaching full yield potential. With N fertilizer prices rising, it is important to use N efficiently.
Zane Helsel