Effect of Pellet Size on Defoliation and Estimated Kill of Small Stems Treated with Hexazinone

Hexazinone [3-cyclohexyl-6-(dimethylamino)-l-methyl-l,Z,5-tria~in~2,4,(lH,ZH)-dione] was tested in the 2, 1, and 0.5 cc size uellet (10% ai) against very small stems [average height, 1.97m; average ground line diameter (GLD), 2 cm] of water oak, Quercus nigra L., at 1.12 and 2.24 kg/ha on a sandy loam soil. First year defoliation of water oak by the 0.5 cc pellet at 2.24 kg/ha was significantly better than the 2 cc pellet at the same rate (88% and 59% respectively). Defoliation by the 0.5 cc pellet at 1.12 kg/ha (63%) was as good as defoliation from the 2 cc pellet at 2.24 kg/ha. On the basis of previous experiments, absolute kill of water oak in this study was calculated. The 0.5 cc pellet at 2.24 kg/ha will result in kill of 56% of the small stems in this study and the 2 cc pellet at this same rate will kill 32% of the stems. Reduction of the pellet size from 2 cc to 0.5 cc can result in product which is more effective and make its use feasible on some sites where it is not currentlv recommended.