-3- 



WEEDS 



PREEMERGENCE HERBICIDES 



In the rush to plant corn, some farmers have delayed the application of preemergence 

 herbicides. Lasso or Ramrod and their combinations with AAtrex (atrazine) can be ap- 

 plied until annual grasses have two leaves. However, the earlier preemergence herb- 

 icides are applied, the more effective they will be. 



Using the rotary hoe before weeds emerge will help keep many small weeds under con- 

 trol. However, rotary hoeing may be more difficult on some of the cloddy and trashy 

 fields that have resulted from the minimum tillage used this spring. 



The triazine herbicides , AAtrex, Bladex, or Outfox, can be applied until annual 

 grasses are 1-1/2 inches tall. This is usually within two to three weeks of planting. 

 Applying these herbicides to corn that is growing under stress can cause yellowing 

 and stunting, but the injury is usually temporary. 



Do not add any wetting agent or oil to Bladex, or serious crop injury may result. Ad- 

 ding an emulsifiable oil to AAtrex will help kill weeds more rapidly. Outfox is al- 

 ready formulated in oil. Broadleaf weeds can be controlled with 2,4-D, Banvel, or a 

 mixture of the two. Banvel is more effective than 2,4-D on smartweed and also helps 

 control Canada thistle. However, the risk of injury from drift to soybeans or other 

 nearby susceptible plants is greater with Banvel. Spraying early, before soybeans 

 are planted or at least while they are small, is one way to help minimize this risk. 



Revised rates for Sencor . The following table gives the revised rates for Sencor 

 (metribuzin) . Careful application of Sencor is necessary in order to minimize the po- 

 tential for soybean injury. Combinations with Sencor have not been cleared. 



Pounds of Sencor 50-Percent Nettable Powder Per Acre 



Organic matter content (percent) 



Less than 2 2 to 4 Over 4 



LIGHT SOILS 



(sandy loam, loamy sand) DO NOT USE 3/4 1 



MEDIUM SOILS 



(loam, silt loam, silt, 



sandy clay, sandy clay loam) 3/4 to 1 1 to 1-1/4 1-1/4 to 1-1/2 



HEAVY SOILS 



(silty clay, silty clay loam, 



clay, clay loam) ' 1 to 1-1/4 1-1/4 to 1-1/2 1-1/2 to 1-3/4 



TIMELY PRECAUTIONS 



In the rush of this busy season, don't forget to: 



1. Calibrate and calculate dosages accurately. Overdosing can cause crop injury or 

 carryover, while underdosing can cause poor performance. 



2. Read and heed all label instructions and precautions. 



