Crabgrass and Other Weed Grasses 



(1) For pre-emergence control of annual weed grasses and many broad- 

 leaved weeds in areas of plentiful moisture: 2,4-D as a spray at 1 to 2 

 pounds per acre (for small lawns use highest rate recommended on con- 

 tainer label) applied just before germination of weed grasses. This treat- 

 ment is successful only when soils are moist. If some of the crabgrass 

 has emerged, use a mixture of 1-1/2 pounds of 2,4-D and 3/4 pound of 

 PMA. 



(2) For pre-emergence control of crabgrass: PMA at 3/4 pound per 

 acre (or o pints of a PMA formulation containing 10 percent PMA by 

 weight) in 40 gallons of water. For small lawns, 2 ounces or 4 tablespoons 

 of PMA in 2 gallons of water per 1,000 square feet of area to be treated. 

 Treatments may be applied any time between emergence of crabgrass 

 and the two-leaf stage of growth. Apply 2 additional treatments at 7- to 

 10-day intervals. PMA is poisonous, but need not be hazardous if reason- 

 able care is used (see Comments and Precautions at the end of this sec- 

 tion). NOTE: Sodium arsenite is used widely for crabgrass control on 

 extensive turf areas. It should be applied only by experienced applicators. 

 KOCN and disodium monomethyl arsonate also have been used as crab- 

 grass herbicides with varying degrees of success. They should be applied 

 according to manufacturer's instructions. 



(3) For control of perennial grasses such as orchardgrass, timothy , 

 quackgrass, nimblewill, and others : Dalapon at 1/4 pound dissolved in 1 

 gallon of water, applied to individual plants or infested areas. Since lawn 

 grasses are also killed by this treatment, use care in treating weeds and 

 limit the areas sprayed. Dalapon usually will disappear from warm, moist 

 soil within 3 to 6 weeks, but persists longer in cool or dry soils. 



Comments and precautions. - -(a) PMA, DNBP, and sodium arsenite 

 are poisonous to warm-blooded animals. They usually are not hazardous 

 to man or animals after they are applied to lawns for weed grass con- 

 trol. As a precautionary measure, however, keep children and animals 

 off sprayed areas until after the first rain (or sprinkling) following 

 treatment. 



(b) KOCN should be used with care on lawns containing bentgrasses 

 and fescue grasses. Avoid use of 2,4-D on bentgrass lawns at rates 

 of more than 1/4 pound per acre. 



(c) Flowers, shrubs, and trees may be damaged by spray drift or 

 vapors, which may be avoided by spraying when wind velocities are low. 

 Use only salts or low-volatile esters of 2,4-D or MCPA. All herbicides 

 available for weed control in lawns should be used according to manu- 

 facturer's directions. 



(d) Broadleaved weeds such as wild onion, wild garlic, dandelions, 

 and plantain may be killed with localized treatments of 2,4-D without 

 spraying the entire lawn. For control of spot infestations of wild onion 

 or wild garlic, use 5 ounces or 10 tablespoons of an amine salt of 2,4-D 

 in approximately 1 gallon of water. Place a rubber glove over your hand 

 to protect it from the chemical and pull an absorbent cotton glove over 

 the rubber glove. Apply the solution to wild onions or wild garlic by 

 dipping a gloved hand into the mixture then firming the hand around the 

 tops of the weed. Press hard enough to break through the waxy coating 

 on the leaves. This will permit the chemical to penetrate into the plant 



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