sunflowers, shepherds-purse, prickly lettuce, plaintain, docks, field bind- 

 weed, and others: Ester or amine salt of 2,4-D or MCPA at 1/4 to 1/2 

 pound in 5 to 20 gallons of water per acre applied after cereals are well 

 tillered (usually 4 to 8 inches tall), but before the early boot stage. Growth 

 of wild onion, wild garlic, Canada thistle, sowthistle, curled dock, butter- 

 cup, field bindweed, and whitetop in arid areas, and several other weeds 

 may be effectively inhibited but not necessarily killed. Grasses and several 

 perennial weeds, such as horsenettle, white cockle, milkweed, and others, 

 will not be controlled by the treatment. 



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

 mountain region, 2,4-D should be applied at 1/2 to 1 pound per acre to 

 control most weeds infesting small grains. Here 1 to 2 pounds of 2,4-D 

 may be required to control semitolerant weeds, and these rates may be 

 used without serious injury to the small grains. In other agricultural 

 areas, rates of more than 1 pound per acre should be used only when 

 necessary to kill weeds causing serious damage to small grains. 



Both 2,4-D and MCPA at moderate rates of treatment can be used to 

 control weeds in wheat, barley, and oats without injuring crops if treat- 

 ments are restricted to the most tolerant stages of growth of the cereals. 

 Greatest benefits to the grain crop result from early removal of the 

 weeds. Fall treatments usually are severely injurious to winter small 

 grains. Some varieties of oats are susceptible to injury from the seedling 

 to the tillering stages of growth and are more tolerant to sprays of 2,4-D 

 at the boot stage and thereafter. 



Applications of 2,4-D or MCPA to cereal crops in the susceptible 

 stages, such as the early seedling stages, before tillering or during the 

 late jointing stages or the boot stage, and early heading stages, may 

 result in reductions in yield and associated deleterious effects on the 

 plants. 



If cereal crops are underseeded to legumes, use minimum rate of 

 amine salts of 2,4-D, MCPA, or DNBP necessary to control weeds (See 

 Small Grains Underseeded with Legumes). Most legumes are susceptible 

 to 2,4-D and MCPA, and serious injury may result if these herbicides 

 are applied at rates greater than 1/4 pound per acre. If cereals are 

 underseeded with legumes, application of MCPA or 2,4-D should be 

 delayed until the maximum small grain canopy has developed, but not 

 later than the early joint stage. The order of tolerance of these crops to 

 2,4-D is as follows, with the most tolerant listed first: wheat, barley, 

 and oats. Oats should not be sprayed unless heavily infested with weeds. 

 Yields may be reduced by applications of 2,4-D made at any time from 

 emergence to heading. Oats, however, are more tolerant to MCPA than 

 to 2,4-D. 



FLAX 



Post -emergence . --For control of broadleaved weeds- -mustard, lambs- 

 quarters, pigweed, pennycress, cocklebur, marsh-elder, and ragweed: 

 Amine or sodium salts of MCPA or amine salt of 2,4-D at 1/8 to 1/4 

 pound in 5 to 20 gallons of water applied when weeds are small and flax is 

 2 to 6 inches tall. For Southwestern flax growing area: 2,4-D or MCPA at 

 1/2 to 3/4 pound per acre. 



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