Amitrol 17 



(1) For control of Canada thistle and leafy spurge: Amitrol at 4 to 8 

 pounds per acre. Repeated applications usually are necessary. 



Soil Sterilants 



(1) For control of deep-rooted broadleaved species in small patches in 

 cultivated fields: Soil sterilants, such as sodium chlorate, borax, or mix- 

 tures of these two. Chlorate should be applied at 3 to 10 pounds per square 

 rod, borax at 15 to 40 pounds, and mixtures at 6 to 20 pounds. Surviving 

 plants should be treated again in subsequent years. 



PERENNIAL GRASSES, RUSHES, AND SEDGES 



(1) Cultivation and combinations with herbicides : Johnsongrass, Ber- 

 mudagrass, and quackgrass in cultivated fields can be most easily and 

 economically controlled by frequent cultivation- -every 2 or 3 weeks during 

 one growing season. Frequently, the amount of cultivation necessary can 

 be greatly reduced by applying TCA at 25 to 50 pounds or dalapon at 10 

 to 20 pounds, or amitrol at 3 to 5 pounds per acre as a foliage and soil 

 surface treatment 1 week before plowing or disking in late fall or early 

 spring. Intertilled row crops should be grown the first year following such 

 treatments to provide frequent tillage, competition for light, and permit 

 spot cultivation or chemical treatment to control surviving plants or patches 

 of grass. 



(2) P replanting : The application of 4 to 5 pounds per acre of dalapon in 

 the spring when quackgrass is 4 to 10 inches tall, followed by plowing in 

 about 1 week, gives good reductions in stand. Planting of corn or other 

 crops should be delayed until at least 4 weeks have elapsed after treatment. 

 In humid regions, early spring foliage applications of 4 pounds of MH, 

 followed in 4 to 8 days by plowing, has given effective control. MH does 

 not leave a toxic residue in the soil and crops may be planted as soon as 

 soil preparation is completed. 



(3) Spot spraying in cultivated row crops : Spot spraying with dalapon at 

 1/4 pound per gallon of water, or TCA 18 at 1/4 to 1/2 pound, about once a 

 month during the growing season will effectively control small patches of 

 Johnsongrass or Bermudagrass in cotton, corn, sorghum, or other row 

 crops. Aromatic oils and dinitro-fortified fuel oils also can be effectively 

 used in the same manner. Damage to crops in the treated areas usually 

 will not exceed that caused by hand hoeing heavy weed infestations. 



(4) Control of Rushes : For control of horsetail rush, apply amitrol at 

 3 to 6 pounds when the weed is 12 to 18 inches tall. 



17 Amitrol cannot be recommended (as of April 1, 1958) for use on Canada thistle and leafy spurge on cropland 

 since evidence has not been developed to prove it will leave no residue or/and tolerances have not been set under 

 Public Law 518. 



18 TCA cannot be recommended (as of April 1, 1958) for use on corn since evidence has not been developed to 

 prove it will leave no residue or/and tolerances have not been set under Public Law 518. 



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