Comments and precautions .- -In the western Great Plains and Inter- 

 nnountain region, 2,4-D at 1/ 2 to 1 pound per acre usually is suggested 

 for control of nnost weeds in corn. 



If corn is nnore than 12 inches tall, drop nozzles maybe advantageous 

 to direct the spray to the top of the weeds and to partially reduce the injury 

 hazard of spraying large corn. 



Some injury to corn from 2,4-D applications made at any time from 

 emergence to tasseling may occur if the treatment is applied during condi- 

 tions favoring rapid growth. Avoid applications w^hen temperatures are high 

 and corn is grow^ing at a nnaximum rate. Use the esters of 2,4-D at the low^er 

 rate and the amine salts at the higher rate in the range of rates suggested. 

 Severe reductions in seed set may occur if applications are made during 

 the 2-week period just before silking and until the silks are dry. Hybrids 

 vary in their susceptibility to 2,4-D but these differences are of little inn- 

 portance at rates below^ 1/2 pound per acre. Avoid cultivation for several 

 days after treatment in order to reduce stalk breakage if brittleness de- 

 velops. 



(3) Directed post-ennergence treatment at lay-by .- -For control of annual 

 grasses and broadleaved weeds from after the last cultivation until harvest: 

 Esters or amine salts of 2,4-D applied at the rate of 1/2 pound per acre to 

 base of cornstalks, and in such a manner as to spray weeds in the row^ (post- 

 emergence), and at rate of 1-1/2 pounds per acre to soil between rows to 

 prevent new weed growth (pre-emergence). Spray is applied with drop nozzles 

 having different volume capacities. Example: Prepare a solution in proportion 

 of 1/2 pound of 2,4-D to 5 gallons of water. Direct a nozzle delivering solution 

 at rate of 5 gallons per acre (equal to 1/2 pound of 2,4-D) on top of w^eeds in 

 the row^; direct a second nozzle delivering at rate of 15 gallons per acre (equal 

 to I-I/2 pounds of 2,4-D) on soil between rows. 



SORGHUM 



Post -emergence . -- The use of 2,4-D for weed control in sorghunn. is sug- 

 gested only as an ennergency treatment when weeds cannot be controlled by 

 cultivation. When 2,4-D is used as a post-emergence spray, it should be 

 applied at the lowest rate necessary for weed control and not to exceed rates 

 suggested for weed control in corn. Sorghums are most tolerant to 2,4-D in the 

 4- to 12-inch stage of growth. Precautions regarding weed control in corn 

 apply also to sorghum. 



WHEAT, BARLEY, AND OATS- -FALL OR SPRING-SEEDED 



Underseeded With Legunnes 



Post -emergence . --For emergency control of serious infestations of mus- 

 tard, yellow- rocket, and other broadleaved weeds if cereal crops are tinder - 

 seeded with a mixture of legumes such as alfalfa, birdsfoot trefoil, lespedeza, 

 red clover, sw^eetclover, \vhite clover, or other legumes: Amine salt of 2,4-D 

 or MCPA at 1/8 to l/4 pound in 5 to 20 gallons of water per acre, or amine 



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