Most volatile herbicides, such as Sutan and Vernam, should be incorporated immediately 

 after application. The Treflan label allows the use of a 4-hour delay in incorporation, 

 but the sooner the better. Lasso and AAtrex can be incorporated, but this is not neces- 

 sary unless you are trying to control yelloiv nutsedge. 



Check. fields for weedy spots in corn. Giant ragweed is now germinating. Smartweed will 

 soon start. Giant foxtail and pigweed will start germinating in about one to two weeks, 

 depending on the temperature. 



If you find areas of high infestation, it may be worthwhile to consider broadcasting 

 a herbicide. These areas are often along drainageways , turn-rows, headlands, and fence 

 lines where it is most difficult to cultivate and use a rotary hoe. You can use a band 

 application of herbicide, and cultivate the rest of the field. 



Yellow nutsedge (Cyperus esoulentus), often called nutgrass , has become a serious weed 

 problem in many areas of Illinois. It is a sedge (with a triangular stem and three- 

 ranked leaves), rather than a true grass (with a round stem and two-ranked leaves). It 

 overwinters primarily as tubers (nutlets), which sprout in the spring and form rhizomes. 

 A coronal node is formed on the rhizome about 1 to 1-1/2 inches below the soil surface. 

 The crown area forms roots, shoots, and new rhizomes. New rhizomes form more plants at 

 first; later in the season, they turn down and develop new tubers for overwintering. 



Thus, the crown area that develops below the soil surface is a critical area for yellow 

 nutsedge control. The most-effective control program involves a combination of preplant 

 tillage, an incorporated herbicide, and postplant tillage. 



Nutsedge is usually found in low- lying, wet areas. It generally emerges about corn- 

 planting time, or by the time the plants emerge. 



The herbicides for nutsedge control in corn are alachlor (Lasso) , butylate (Sutan) , and 

 atrazine (AAtrex). EPTC (Eptam) has provided adequate control, but corn tolerance has 

 not been sufficient. The best treatments in research trials have been either butylate 

 (4 pounds per acre), or alachlor (3 to 4 pounds per acre) --applied preplant incorporated 

 and followed by an early postemergence treatment of atrazine (2 pounds per acre) plus 

 nonphytotoxic oil (1 gallon per acre) . 



Nutsedge control in soybeans allows the farmer to locate the areas, use preplant tillage, 

 and broadcast a herbicide just on these areas, because soybeans are planted later than 

 corn. The two herbicides that have proven useful for nutsedge control in soybeans are 

 alachlor (Lasso) and vernolate (Vernam) . Both of these should be used at the highest 

 recommended rate, and should be incorporated. Incorporation can be combined with preplant 

 tillage. 



Fall panicum is a grass weed that continues to germinate late in the season. Earlier 

 planting and earlier "lay-by," combined with a greater dependence on chemicals and a 

 reduction of tillage, have invited late-emerging weeds --especially in wide-row corn. 



Fall panicum is a problem throughout the state, but the greatest difficulty is in 

 southern Illinois --because of wider rows, longer growing seasons, and a greater depend- 

 ence on atrazine as a herbicide there. Fall panicum is a particular problem on zero- 

 tillage corn. 



Simazine (Princep) is better than atrazine (AAtrex) on late-emerging grasses, such as 

 fall panicum and crabgrass. Alachlor (Lasso) and butylate (Sutan) are two other her- 

 bicides with enough persistence to control late-emerging grasses. Many people arc 



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