Where tillage is minimized and the herbicide is not sufficiently diluted by mixing 

 with more soil, there is more chance of carryover injury. Some increase in carry- 

 over may be associated with broadcast applications. Make careful observations in 

 your fields this year and try to select rates for next year that will be sufficient 

 for weed control without residue problems. Consider combining herbicides and 

 rotating herbicides to decrease residue problems. The surest way to avoid herbi- 

 cide injury is not to use herbicides. But in spite of the occasional problems, 

 the benefits from herbicides usually far outweigh any disadvantages. 



Injury to fall -seeded wheat where Tref Ian had been used on soybeans has not been 

 serious in the past, but it may pay to try to avoid planting wheat this fall where 

 Tref Ian was applied unusually late this spring. 



Help make America beautiful . Give a boy a haircut, and spray weeds in fencerows. 

 One quart of 2,4-D and 5 pounds of Dowpon in 50 gallons of water will treat 

 2 miles of fencerow 4 feet wide. Some custom applicators should be able to pick 

 up extra business and satisfied customers with a fencerow spray program. Vary 

 the herbicides and rates to fit the situation. And use care to avoid injury to 

 adjacent crops. 



DUCKWEED CONTROL 



Frequently ponds become infested with duckweed, Lemna minor. This species is 

 difficult to control because the mature seed -producing plant is small, and a large 

 number of plants are involved. Applications of Diquat or disodium aquathol, 1 cup 

 of herbicide diluted to 4 gallons, applied directly to the duckweed as a fine 

 spray will reduce the duckweed population. Applications about every two weeks 

 will be required to keep the duckweed under control. We have not been able to 

 eliminate duckweed from a body of water, but by the repeated applications have 

 kept the water surface relatively free of duckweed. 



READ THE 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. 



Weeds: Ellery Knake, Department of Agronomy; Robert Hiltibran, Illinois Natural 

 History Survey. 



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. 



