I 



is being used throughout the United States wherever a quick and positive 

 kill is needed on small or medium-sized scrub oaks. It is less effective 

 on large, tall trees. 



The next method developed at Alexandria is that of pouring a 

 water solution of Ammate into a frill made around the tree trunk at a 

 convenient chopping height. A frill is a single-hack girdle that severs 

 the bark and peels it back slightly (fig. 15B). A 19- 3 percent solution is 

 recommended; it is made by dissolving 2 pounds of Ammate crystals in a 

 gallon of water. 



The frill-and- solution method kills large hardwoods readily and 

 is cheaper and more convenient than the crystal-in-notch system. There 

 is usually some sprouting, but if the pines beneath the hardwoods are at 

 least 1 or 2 feet tall they can usually keep ahead of the sprouts. Many 

 industrial foresters in Louisiana and elsewhere now use this as the 

 standard hardwood control method. 



Complete instructions for using Ammate are available in a leaf- 

 let, "How to control southern upland hardwoods with Ammate, 11 pub- 

 lished in 1949 by the U. S. Department of Agriculture. 



In recent years, many new chemicals have come into use as 

 agricultural weed-killers. The Alexandria Research Center has screened 

 and tested the best of these on scrub hardwoods and recommends two of 

 them: 2,4, 5-T and 2,4-D. 



When applied in frills during spring or fall, 2, 4, 5-T (16 pounds 

 of acid equivalent in 100 gallons of diesel oil) kills over 90 percent of the 

 tree tops, with not much sprouting from stumps. 2,4-D (16 pounds of 

 acid equivalent in 100 gallons of diesel oil) is a little cheaper but not 

 quite so thorough. Both treatments cost slightly more than Ammate so- 

 lution in frills but are more effective, especially in sprout reduction. 



Trunk spraying with the oil solution of 2, 4, 5-T is also useful 

 (fig. 15C). Scrub oaks and hickory were killed by spraying the lower 16 

 inches of the trunks until the bark was wet. Trunk spraying costs nearly 

 one-third more than pouring solution into frills, but ax work is elimi- 

 nated and the costs may be reduced by further tests. 



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