at the lower 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 differences are 

 of little importance at rates below 1/2 pound per acre. Avoid cultivation 

 for several days after treatment in order to reduce stalk breakage if 

 brittleness develops. 



(3) Directed post-emergence treatment at layby . --For control of annual 

 grasses and broadleaved weeds from after the last cultivation until har- 

 vest: Ester or amine salt 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 be- 

 tween 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 weeds in the row; direct a second nozzle deliver- 

 ing at rate of 15 gallons per acre (equal to 1-1/2 pounds of 2,4-D) on soil 

 between rows. 



SORGHUM 



The use of 2,4-D for weed control in sorghum is suggested only as an 

 emergency treatment when weeds cannot be controlled by cultivation. When 

 2,4-D is used as post-emergence spray, it should be applied at 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 



Small Grains Underseeded With Legumes 



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

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

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

 lespedeza, red clover, sweetclover, white clover, or other legumes: Amine 

 salt of 2,4-D or MCPA at 1/8 to 1/4 pound in 5 to 20 gallons of water per 

 acre, or amine salt of DNBP at 3/4 to 1 pound in 30 to 50 gallons of water 

 per acre. DNBP is less likely to injure legumes than 2,4-D. If DNBP is 

 used, it should be applied only when the weeds are in the seedling stage. 

 The 2,4-D or MCPA application should be made after cereals are well 

 tillered (usually 4 to 8 inches tall), but before reaching boot stage. The 

 legumes are less likely to be injured if a small grain canopy is allowed to 

 develop before applying 2,4-D or MCPA. Apply the lowest gallonage pos- 

 sible at low pressure in order to reduce penetration of the canopy with the 

 spray. 



Comments and precautions .- -Avoid use of post -emergence applications 

 of 2,4-D and MCPAunless the weed infestation is serious enough to result 

 in reduction or loss of legume stands and reduced small grain yields. 



Small Grains Not Underseeded With Legumes 



Po st - emer gene e. - -For control of mustard, wild radish, yellow-rocket, 

 ragweed, wild vetch, lambs quarters, pigweed, cocklebur, smartweed, 



- 18 - 



