Herbicide Plus Various Additives for Follow-up Control of Shredded Mesquite

Abstract

One group of 300 honey mesquite trees that had been shredded in the summer of 1969 were sprayed in June, 1970, and another group of 300 trees were sprayed in June, 1971 with 2,4,5-T (amine and ester formulation) plus an additive. Niacin (1.6 ppm) with 2,4,5-T amine applied in 1970 produced a high percentage root mortality on 1-year-old regrowth, whereas either biotin (2.4 ppm), pyridoxin (2.1 ppm), or thiamine (3.4 ppm) plus 2,4,5-T amine applied in 1971 produced a high percentage root mortality on 2-year-old regrowth. The use of these B-vitamins plus 2,4,5-T appears to be an effective and inexpensive method of follow-up control for regrowth of shredded honey mesquite. The cost of the B-vitamins was less than 5 cents/acre.