• Martin, S. Clark
  United States Department of Agriculture
  
• Clark, F. Bryan
  United States Department of Agriculture
  
• Chapman, Arthur G.
  Columbia (Missouri) Forest Research Center
  

Controlling unwanted hardwood reproduction is difficult on forest and rangeland in the Missouri Ozarks. In the past, Ozark farmers have chopped, girdled, burned, grubbed, and goated in attempting to get rid of hardwood sprouts. These methods are seldom successful and usually cause accelerated erosion. The farmer needs a more effective, less destructive way to do this job.

Several promising new weed-killing chemicals are being tested on the Sinkin Experimental Forest in south-central Missouri. Results of a study begun in June 1950 to test the effectiveness of foliage sprays of ammate, 2, 4-D, and 2, 4, 5-T for controlling hardwood seedlings and sprouts are reported here.

The study was made on a relatively level, dry Ozark ridgetop. Past cutting and repeated burning have left a dense stand of hardwood sprouts plus a scattered overstory of larger trees average about 60 square feet of basal area per acre; most of them are less than 10 inches d.b.h. Post oak (Quercus stellata Wangenh.), black oak (C. velutina Lam.), and blackjack oak (Q. marilandica Muenchh.) are the more abundant overstory species. Overstory trees were not treated.

The understory consists of about 3,500 clumps of hardwood sprouts per acre. The most numerous species are blackjack oak, post oak, black oak, white oak, and hickory. Most of the sprout clumps developed after tree reproduction was killed back to the ground line by fire in 1944. Since the tops have been killed back several times by fire, the root systems are relatively large and much older than the tops. At the beginning of the study the sprout clumps averaged 5 to 6 years in age, 2.4 feet in height, and 3.1 feet in crown diameter.