Established Grasses for Seed Production 



For control of nnost annual and many perennial broadleaved weeds in grass- 

 seed fields: Amine salts or esters of 2,4-D, 2,4,5-T, silvex, or MCPA 

 at 1/2 to 1-1/2 pound per acre applied as a spray after grasses are well 

 tillered, but before reaching the boot stage will control weeds without signifi- 

 cant injury to the grasses. Avoid spraying when grasses are in the boot or 

 early heading stages. Most grasses are tolerant to treatment; however, 

 bentgrasses and a few others have been reported as being more sensitive. In 

 recent investigations, monuron and diuron have provedpromising for the con- 

 trol of annual weed grasses and broadleaved weeds in established perennial 

 grasses grown for seed production. 



Established Pastures (including pastures with white, Ladino, and alsike 

 clovers in mixtures) 



(1) For control of most broadleaved weeds, such as ragweed, bitterw^eed, 

 tarweed, boneset, sneezeweed, pigweed, chicory, dandelion, curled dock, 

 burdock, Canada thistle, and others: Post-emergence application of an 

 amine salt or ester of 2,4-D at 1/2 to 1 pound per acre in late spring after 

 the period of initial rapid growth of legumes, but while weeds are still small. 

 Foliage applications of 2,4-5-T may be used for control of some woody plants 

 that are resistant to 2,4-D, but more injury to the clovers and killing of 

 lespedeza may be expected than with 2,4-D. 



(2) For control of wild garlic, wild onion, curled dock, and other semi- 

 tolerant pasture weeds in many areas: 2 applications of 2,4-D each year for 

 2 or more years, are usually required. One application should be made during 

 the period, October to December, and the other during the period, February to 

 May. 



(3) For renovation of sod: Dalapon at 4 to 8 pounds per acre is effective in 

 killing many grasses in preparation for renovating pastures. Amitrole alone, 

 or in combination with dalapon, has been useful in the northeastern United 

 States. The herbicide treatments may be made in the fall to kill grasses and 

 to reduce the number of diskings necessary for seedbed preparation. The 

 area should not be grazed until the following growing season. If perennial 

 broadleaved weeds are present the pasture should be sprayed with 2,4-D, 

 2,4,5-T, or MCPA at 1 to 2 pounds per acre in the spring or early summer 

 before renovation is attempted. The dalapon residues decrease in warm, 

 moist soils in 3 to 4 weeks and seedings can then be made. Amitrole dis- 

 appears more rapidly from the soil. 



Comments and precautions . --Good pasture agronomic practices, includ- 

 ing proper fertilization and efficient grazing practices, are necessary for 

 successful control of weeds. When these practices have been followed within 

 the limits of practicality and weed infestations still occur, 2,4-D, 2,4,5-T, 

 or mixtures of these herbicides, are effective and safe for weed and woody 

 plant control. Some injury nnay occur to legumes, especially from the 

 repeated treatments of 2,4-D, MCPA, and 2,4,5-T. The legumes may 

 recover or may be reestablished after satisfactory control of the 

 weeds. 



36 - 



