Herbicide Concentrations in Honey Mesquite Phloem

Abstract

Herbicide content in honey mesquite(Prosopis juliflora(Swartz) DC. var.glandulosa(Torr.) Cockerell) phloem 48 hr after treatment was higher in stems within 20 cm of the foliage than in those near the soil line. Similar levels of (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T) occurred from applications of either 0.56 or 1.12 kg/ha, whereas three times as much 4-amino-3,5,6-trichloropicolinic acid (picloram) occurred in plants sprayed with the high rate than in those sprayed with the low rate. Herbicide concentration was highest in June and lowest in August.

Effect of 2,4,5‐T and picloram on the regeneration of blackberry (Rubus procerus P.J. Muell) from root segments

“…The value of 2 x 10-'M for the concentration of 2,4,5-T in the roots is in agreement with data presented by other authors. Calculations from data of Davis et al (1972) on the concentration of 2,4,5-T in the phloem periderm layer of honey mesquite (Prosopis Juliflora (Swartz) DC. var glandidosa (Torr.)…”

A review of foliar absorption and translocation of 2,4‐D and 2,4,5‐T

“…They have shown that 2,4,5-T translocation in mesquite {Prosopis julifiora) is decreased when picloram is added although picloram translocation is enhanced in the presence of 2,4,5-T. This was again demonstrated by Davis et al (1972) when they measured the 2,4,5-T and picloram concentrations in the phloem of mesquite. Addink (1973) has found that dicamba increases the amount of 2,4-D translocated in leafy spurge {Euphorbia esula) although translocation of dicamba is reduced by the presence of 2,4-D. Uptake of 2,4-D was not stimulated by dicamba so dicamba must be acting on the translocation system in this case.…”

“…This parallelled a similar increase in absorption of the herbicide as the concentration increased. Davis et al (1972) found that 2,4,5-T butoxyethanol ester applied at 0 56 and 112 kg/ha did not result in significant differences in the concentration of the herbicide in the phloem tissue of mesquite {Prosopis julifiora). However, translocation of 2,4,5-T, applied as the butoxyethanol ester, from treated leaves of blackjack oak {Quercus marilandica) was found to increase as the amount of herbicide applied was increased (Badiei et al, 1966).…”

“…This, however, also correlated with herbicide absorption and higher temperatures. Davis et al (1972) found that the concentration of 2,4,5-T in the phloem of mesquite {Prosopis julifiora) reached a maximum in June when the air temperature was high.…”

Influence of Environment and Stage of Growth on Honey Mesquite (Prosopis glandulosa) Response to Herbicides

“…In west Texas, when growing conditions are favorable, 0.6 kg/ha of 2,4,5-T generally kills most of the aboveground stems and about 25% of the plants (7). The combination of 2,4,5-T plus picloram has also been used commercially and is slightly more effective than 2,4,5-T alone (2, 13) 5 ' 6 . The most effec tive treatments have occurred about 50 to 90 days after the first leaves appear in the spring when they are fully formed and dark green.…”