-5- 



Preplant. If incorporation can be a part of seedbed preparation and the preplant 

 choice fits into your program, go ahead with preplant- incorporated herbicides. 

 They are the best choices for controlling yellow nutsedge, wild cane, and johnson- 

 grass seedlings in both corn and soybeans. 



Remember that Sutan, Eptam, Eradicane, or Vernam need to be incorporated immediately. 

 Also, incorporation needs to be thorough for herbicides of low solubility such as 

 Treflan and Cobex. If you use a field cultivator as the final incorporation tool, 

 be sure to pull a drag in order to level the soil behind the back shanks, or streaked 

 weed control may result. 



Preemergence. Herbicides applied preemergence are another alternative for weed con- 

 trol. Planter attachments offer the possibility of banding. However, planter treat- 

 ments may delay planting, and banding may mean that cultivation needs to be performed 

 sooner. Do not plant too many acres and then expect to come back later and apply pre- 

 emergence herbicides, since rains may prevent their timely application. 



Some herbicides such as Ramrod or Lasso and their combinations with AAtrex can be ap- 

 plied until annual grasses have one to two leaves, but earlier application is usually 

 much more effective. The soybean herbicides Preforan and Soyex or Solo should not be 

 applied after soybeans have emerged, because severe injury can occur. 



Postemergence. If you must control annual grasses after they emerge, then the choices 

 are few, and the application must be early and timely. The triazine herbicides AAtrex, 

 Bladex, and Outfox can control the foxtails (giant, green, and yellow) and barnyard- 

 grass --if applied before the grasses are 1-1/2 to 2 inches tall. However, the control 

 of fall panicum or crabgrass may not be adequate. If you rely on a postemergence pro- 

 gram to control annual grasses, an application that is delayed by rain may mean a dras- 

 tic decrease in performance. 



Broadleaf weeds are controlled by the herbicides just listed; but if broadleaf weeds 

 are the only problem, you can use 2,4-D or Banvel. Banvel is better on smartweed 

 than 2,4-D, and corn tolerance is somewhat better with Banvel. However, the drift 

 to soybeans can be more of a problem with Banvel. 



Postemergence herbicides for soybeans will not adequately control annual grasses. 

 These must be controlled earlier- -either with a soil-applied herbicide or by rotary 

 hoeing and cultivation. The choices for postemergence weed control in soybeans are 

 limited in effectiveness, timing, and usage. 



PRECAUTIONS 



Observe the label directions and precautions with all of the postemergence herbicides 

 concerning rate; time of application; drift reduction; use of surfactants, wetting 

 agents, or oils; and application to crops growing under stress conditions. 



Always read and heed the herbicide label. Closely read and observe the use precau- 

 tions relating to the disposition of grain and forage. Take special note of pre- 

 plant and rotational cropping statements. Proper mixing and accurate rate selection 

 and application are absolutely necessary in order to minimize crop injury and herbi- 

 cide carryover problems. For further information on weed control, see the 197 Z Field 

 Crops Weed Control Guide. Copies are available from your local Extension Adviser. 



HERBICIDE COMBINATIONS 



The recent increase in the number of these combinations has created a real dilemma. 

 Why use herbicide combinations? What are their advantages? One of the main reasons 



