WEEDS 



Where Banvel-D (dicamba) was sprayed postemergence on corn, we have had several 

 reports of injury to nearby soybean fields. Soybean leaves become crinkled and 

 cupped, and the top leaf buds do not open and expand normally but are somewhat 

 clustered. 



Corn has relatively good tolerance to Banvel-D, and this herbicide controls many 

 of the same weeds as 2,4-D. One of the major differences is that Banvel-D usually 

 gives better control of smartweed than does 2,4-D. 



However, considering the number of cases where injury to nearby soybeans occurs 

 from Banvel-D each year, we strongly suggest that other alternatives be explored 

 for smartweed control. One of the best alternatives is Atrazine. Smartweeds are 

 very susceptible to Atrazine- -applied preplant, preemergence , or early postemergence. 

 We have obtained excellent smartweed control on dark soils with rates of 1-1/4 

 pounds or more of Atrazine 80W. 



Will yields be affected in fields now showing injury? Each field needs to be con- 

 sidered individually, since the degree of injury will vary. Slight cupping and 

 crinkling of the leaves does not necessarily mean that there will be a yield re- 

 duction. Selecting several plants at random from both the affected and unaffected 

 areas of the field and counting pods should give some indication of the serious- 

 ness of the problem before harvest. A comparison of yields at harvest provides 

 one of your best means of appraisal. 



READ THE INSECTICIDE LABEL AND FOLLOW ALL PRECAUTIONS 



This weekly report was prepared as follows: 



Insects: H.B. Petty, Steve Moore, Roscoe Randell, Don Kuhlman, and Stephen 

 Sturgeon, University of Illinois College of Agriculture and Illinois Natural 

 History Survey. 



Plant Diseases: M.P. Britton, Department of Plant Pathology. 



Weeds: Ellery Knake, Department of Agronomy. 



Ag Communications: Del Dahl. 



The information for this report was gathered by these people, staff members, 

 county Extension advisers, and others, in cooperation with the USDA Agricultural 

 Research Service, Plant Pest Control Branch. 



