-5- 



If you're planning on a postemergence application of atrazine and oil, get it on 

 early before weeds (including annual grasses and broadleaves) are over 1 1/2 inches 

 tall and definitely within 3 weeks after planting. You may hear occasional success 

 reports with applications made later than this, but delaying the application de- 

 creases your chances of success and increases the chance of herbicide residue the 

 next year. 



Only a few herbicides and phases of weed control are mentioned here. For more 

 complete details refer to the 1968 Weed Control Guide. If you don't have a copy 

 ask your county Extension adviser. 



Current issues of Agronomy News will also contain additional weed control informa- 

 tion. If you are not on the Agronomy News mailing list, drop a card to Agronomy 

 News, N-305 Turner Hall, Urbana 61801. There is no charge for Agronomy News. 



Soybeans 



Herbicide combinations for soybeans haven't been developed as much as for corn. 



In soybeans, Treflan primarily controls annual grasses and pigweed. It gives some 

 control of lambsquarter. We don't have much of anything to combine with Treflan 

 to take care of the other broad- leaved weeds. The rotary hoe is still one of the 

 best bets to clean out the broad- leaved weeds, and it is not likely to decrease the 

 effectiveness of Treflan. 



If annual grass such as foxtail is the major problem in soybeans, Treflan has been 

 one of the most consistent performers. 



If broad- leaved weeds as well as annual grasses are a problem, amiben has a good 

 record for control of many broad- leaved weeds and also does quite well on annual 

 grasses. 



At this point we do not accept the economics or feasibility of combining Treflan 

 and amiben, which has sometimes been suggested. 



Where annual grass and smartweed are the major problems, one possibility would be 

 to incorporate Treflan before planting and follow with a regular surface- applied 

 preemergence application of CIPC at planting time. For smartweed control, 3 or 

 4 pounds of CIPC (active ingredient broadcast or proportionately less banded) 

 should be adequate. 



Labels don't think — people do 



Be sure that your personnel deliver the right herbicides for the crop. Double 

 check, especially if a corn herbicide is being moved after most of the corn is 

 planted and most farmers are planting beans. All due respects to Mom, but when 

 she comes in to pick up a few more bags of pesticide for Dad, be sure of the name. 

 It is not too difficult to confuse names like alanap, aldrin, atrazine, and amiben 

 if you are more familiar with cake recipes than with herbicides. We've already 

 had some problems and could have more with farmers figuring their needs closer to 

 the belt and more last-minute delivery rush this year. 



