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.