Site Relations, Regrowth Characteristics, and Control of Lotebush with Herbicides

Abstract

Regrowth following top removal of lotebush (Condalia obtusifolia (Hook.) Weberb.) seedlings and field transplants followed a typical apical dominance pattern. When 2.5 cm of the stem segments were left intact, sprouting occurred from stem tissues. When stems were completely removed, sprouts originated from root tissues. Lotebush densities on the Texas Experimental Ranch were greater on shallow redland than on deep upland, rolling hill, rocky hill or valley range sites. Aerial application of 2,4,5-T at 1.12 kg/ha was ineffective for control of lotebush, regardless of range site. Basal sprays containing 4 or 8 g/liter of 2,4,5-T + picloram in a diesel oil:water emulsion (1:4) effectively controlled lotebush. Basal sprays of dicamba were less effective than 2,4,5-T + picloram; and 2,4,5-T was ineffective in the emulsion carrier. However, 2,4,5-T in diesel oil reduced the canopies by an average 50 to 70% at 2 years after treatment. At rates greater than 5 g (active ingredient)/m of canopy diameter, monuron pellets reduced lotebush canopies by 85 to 100%. At the same rate, dicamba granules completely reduced the brush canopy and resulted in 86% root kill at 2 years after application. Two g/m of canopy diameter of picloram pellets completely controlled the lotebush.