-4- 



ditch banks. After recent hearings, the Environmental Protection Agency (EPA) 

 announced that it "found no imminent hazard requiring suspension of the regis- 

 tered uses of 2,4,5-T." They also issued this statement: 



"2,4,5-T is a very effective herbicide which is widely used for controlling brush 

 on rangelands and undesirable broadleaf trees in forestry programs. This chemi- 

 cal should be used in such fashion that no residues will result in food or feed. 

 Milk cows should not be grazed on treated areas for a few weeks after treatment, 

 and meat animals should not be permitted to graze freshly treated areas for a 

 few days prior to slaughter." 



So, 2,4,5-T can now be used for brush control, as long as the above restrictions 

 are followed. "Brushkiller" (a mixture of 2,4-D and 2,4,5-T) is also subject to 

 the same restrictions. Silvex or dichlorprop are two brush herbicides that can 

 still be used around ditches and waterways where it is necessary to use something 

 besides 2,4-D. Silvex is sometimes sold under the tradenames of Kuron and Silvi- 

 Rhap. Dichlorprop is soil as Propi-Rhap. 



POSTEMERGENCE AATREX 



Some advisers are concerned about potential injury after they apply atrazine 

 (AAtrex) and oil for grass control in corn. Corn injury can occur with the 

 atrazine-oil combination. This is most likely to happen on corn exposed to 

 stress, such as cold temperatures or frost. 



For maximum weed control on grasses, the grass weeds should be less than 1-1/2 

 inches tall. The rate for atrazine (AAtrex) is 2-1/2 pounds per acre of the 

 SOW material. The oil is usually added at the rate of 1 to 2 gallons per acre. 



Agricultural surfactants are sometimes used rather than oil. Surfactants are 

 usually used at the rate of 1 to 2 quarts per 100 gallons of spray, so you 

 have a smaller volume of material to handle. The performance of oils and sur- 

 factants is about equal. Any difference is usually in favor of the oils. 



Surfactant and oil combinations are presently available. They combine the 

 effectiveness of the oil with the lower volume of the surfactant. These are 

 usually used at the rate of 1 to 2 quarts per acre. 



Remember, when mixing atrazine (AAtrex) and oil, be sure to mix the atrazine 

 with the water first and then add the oil. This prevents "gunking" and disper- 

 sion problems. 



PLANT DISEASES 



PROGRESS REPORT ON SOUTHERN CORN LEAF BLIGHT 



As of June 3, southern corn leaf blight has been found in the following counties: 

 Jackson, Clay, Effingham, Edgar, Coles, Gallatin, Douglas, Jasper, Monroe, and 

 Union. In Jackson County, it was found on the agronomy farm at Carbondale; in 

 Clay County, on corn planted this spring in a farmer's field. In all other 

 cases, blight has been identified only on volunteer corn. So far, there is no 

 indication of any spread to nearby planted corn. There is no cause for alarm. 

 Cur predictions for 1971 are the same as last week (see Bulletin No. 9). 



