POSTEMERGENCE HERBICIDES FOR SOYBEANS 



Tenoran (chloroxuron) is used mainly to control broadleaved weeds where a preemergence 

 herbicide such as Treflan has been used. It gives fairly good control of pigweed, lambs- 

 quarter, smartweed, jimsonweed, morning glory, and cocklebur. 



Apply the herbicide when broadleaved weeds are less than 2 inches high and when grass weed 

 are less than a half inch high. Treat velvetleaf before it is an inch high, because contrl 

 is difficult after that. Tenoran works better on cocklebur after two true leaves emerge, 

 rather than earlier when the "leathery" cotyledons are exposed. 



To broadcast Tenoran, use 2 to 3 pounds of the 50 -percent wettable powder per acre with 1 

 pint of Adjuvan T surfactant added per 25 gallons of spray solution. The rate for banding 

 is proportionately less. Soybeans treated with Tenoran usually show leaf burn, but the 

 injury may not affect yields. 



2,4-D may be broadcast from 10 days before soybeans begin to bloom until mid-bloom, or it 

 can be used as a postemergence directed spray when soybeans are 8 to 10 inches tall and 

 cockleburs are 3 inches tall. It gives fairly good control of annual morning glory and 

 giant ragweed, too. 



After being sprayed with 2,4-D, soybeans may show early wilting, curving or cracking of th 

 stems, and proliferate growth at the base of the plant. If you use too much or apply the 

 chemical under unfavorable conditions, lodging may increase and yields may decrease. 



Postemergence herbicides on soybeans have not gained much acceptance in Illinois. 



SPECIAL ANNOUNCEMENTS 



June 



17, 



June 



17, 



June 



18, 



*June 



18, 



*June 



19, 



June 



19, 



June 



23, 



June 



23, 



June 



24, 



June 



24, 



■X0T1;' 



Office of the Brown County Extension Adviser, Robert Hayward, Mt. Sterling 

 Office of the Henderson County Extension Adviser, Curt Eisenmayer, Stronghurst 

 Office of the Knox County Extension Adviser, Don Teel, Galesburg 

 Office of the Livingston County Extension Adviser, Paul T. Wilson, Pontiac 

 Office of the McLean County Extension Adviser, Gene Mosbacher, Bloomington 

 Office of the Iroquois County Extension Adviser, Ken Imig, Watseka 

 Office of the Whiteside County Extension Adviser, Fred Tincher, Morrison 

 Office of the LaSalle County Extension Adviser, Jim Daugherty, Ottawa 

 Office of the JoDaviess County Extension Adviser, Geo. Swallow, Elizabeth 

 Office of the Winnebago County Extension Adviser, Dick Kerr, Rockford 



THE DATES OF THE LIVINGSTON AND MCLEAN COUNTY MEETINGS HAVE BEEN CHANGED FROM 

 PREVIOUS ANNOUNCEMENTS 



This weekly report was prepared as follows: 



INSECTS: H.B. Petty, Steve Moore, Roscoe Randell, Don Kuhlman, and Stephen Sturgeon, Uni- 

 versity of Illinois College of Agriculture , Urbana-Champaign and Illinois Natural History 

 Survey . 



WEEDS: E.L. Knake, Department of Agronomy . 



AG COMMUNICATIONS: Del Dahl . 



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

 sion advisers, and others, in cooperation with the USDA Agricultural Research Service, 

 Plant Pest Control Branch. 



