Grasshopper Reports

Over the past few days I have received several reports of large grasshopper populations in several soybean fields. Initially, grasshoppers tend to occur along field edges and areas near drainage ditches. No economic damage has been reported due to grasshoppers yet. But consider this an early warning to scout fields. There are no good thresholds established for grasshoppers in corn or soybeans. Generally consider treatment in pre-bloom soybeans if grasshoppers are present and 40% or more defoliation is encountered. When in the pod forming and pod filling stages treatment is recommended with 20% or more defoliation.

Bill Bamka

Wheat Harvest and Storage

 Wheat is being or is ready to be harvested in a good portion of the state, but high temperatures, high humidity and predicted rain showers daily for the next week have the potential to cause problems. Where large amounts of rain fall, getting combines into the field may be difficult. Where fields are passable, grain may be mature but high in moisture. It is important to get wheat out of the field quickly after the kernals have matured to avoid loss of yield, reduced quality and ultimately sprouting in the heads. Combines operate most efficiently and with less kernal damage when grain moisture is between 13-20%. If wheat is harvested much above 14% it needs to be dried relatively quickly to prevent sprouting in storage.  Wheat is harder to dry than corn because of the high humidity this time of the year and because it packs tighter than corn thus grain depths in the bin need to shallower or fan speeds/volumes greater. The following links to publications from Purdue University and the University of Missouri may be useful if the current weather conditions persist and problems are encountered.

http://www.extension.purdue.edu/extmedia/GQ/GQ-11.html
http://extension.missouri.edu/explorepdf/agguides/pests/ipm1022_Pp33-37.pdf

Zane R. Helsel

Cereal Leaf Beetle in Corn

We spent a fair amount of time scouting wheat fields for cereal leaf beetles earlier in the season. Now it is time to focus attention on adjacent corn fields. The adult cereal leaf beetles can now be found in adjacent corn fields. They are primarily found on the perimeter of the corn fields. Though I have encountered them throughout some corn fields. Adult cereal leaf beetle damage appears as longitudinal slits between the leaf veins. Corn plants usually outgrow the injury. Unlike larval damage in wheat, there are no firm thresholds for adult damage in corn. One threshold suggests treatment when 10 or more adults are found per plant and 50% of plants show feeding damage.

Cereal Leaf Beetle Adult
Courtesy Virginia Tech Cooperative Extension

                                                         
Bill Bamka

Soybean Replanting Decisions

I have received several calls about soybean replanting. Making a replanting decision is never an easy task. When evaluating reduced or uneven stands there are a few things to take into consideration. First, do you know what caused the problem in the first place? Planting too deep? Improper planter settings? Herbicide injury? Insect feeding? Possibly planting too early, followed by slow growing conditions? If you do not know what happened the first time, you could be setting yourself up for failure again if you do not address the problem. Second, before deciding to replant you need to determine the density of your current stand. The Hula Hoop method or counting plants in 1/1000 of an acre can be used to do this. Once you know your stand count you can estimate the yield potential of your field. Making the decision to replant can be agonizing, however there are resources to help growers. Purdue University has published a good Soybean Production System fact sheet that clearly guides growers through the replant decision.

Bill Bamka

Keep Alert for Slugs in Soybeans

The recent wet weather can create the opportunity for slug damage in newly planted soybean fields. Occasionally, we have had fields that required replanting due to slug damage. No till fields can be at greater risk for slug problems. Be sure to scout low lying fields and fields with heavy residue. More information on life cycle and pest management options are available in Penn State's fact sheet "Slugs as Pests of Field Crops." 

Bill Bamka