Will Mesquite Control with 2,4,5-T Enhance Grass Production?

Abstract

Highlight: Both honey mesquite density and percent of plants dead the year of aerial spraying with 2,4,5-T proved to be major factors influencing perennial grass production. Sites with sparse honey mesquite stands and very dense stands (over 50% canopy cover) yielded little extra grass after 2,4,5-T application. Heavy mesquite foliage probably prevented adequate leaf coverage with 2,4,5-T in dense stands, and in sparse stands mesquite competed little with the herbaceous plants. Increased perennial grass production of about 540 lb/acre/year would be necessary over a 5-year period to break even with a $4.60/acre aerial applicationof2,4,5-T. With honey mesquite cover of 30%, a plant kill over 80% the year of application was required to provide a 540 lb/acre/year grass increase. However, a 90% kill would provide nearly 750 lb/acre/ year extra perennial grass. Thus, paying particular attention to optimum environmental factors and proper timing for the 2,4,5-T application can pay big dividends.

Some Impacts of 2,4,5-T on a Mesquite Duneland Ecosystem in Southern New Mexico: A Synthesis

“…led to differences in herbaceous plant production among years that were as large as the differences between sprayed and untreated areas. The increase in herbaceous production following spraying is in agreement with the findings of Scifres and Polk (1974) and Dahl et al (1978). McDaniel et al (1982) found that, depending upon rainfall, a significant grass response might occur within 120 days to 3 years after spraying.…”

Converting mesquite thickets to savanna through foliage modification with clopyralid

“…is considered a problem plant in much of the southwestern USA because it reduces forage production for livestock, interferes with livestock handling and reduces off-site water yield (Dahl et al 1978, Bedunah and Sosebee 1984, Teague et al 1997). Treatments that only top-kill mesquite, such as chaining, shredding, high-intensity fires, or herbicides such as triclopyr (3,5,6-trichloro-2-pyridinyloxy-acetic acid, butyoxyethyl ester), compound the problem by stimulating regrowth from stem bases, thus increasing stem numbers and the competitive effects of mesquite (Fisher et al 1959, Scifres et al 1974, Ansley and Jacoby 1998.…”

Effects of fire, grazing, and the presence of shrubs on Chihuahuan desert grasslands

“…Further, overgrazing has not only locally expanded shrub distributions and abundances, but has also contributed to soil erosion, making regrowth, reproduction, and establishment of perennial grasses increasingly difficult (Hennessy et al, 1983;Schlesinger et al, 1990). The presence of shrubs within existing desert grasslands may adversely affect the growth of dominant perennial grasses, especially during periods of drought (Scifres & Polk, 1974;Dahl et al, 1978;McDaniel et al, 1982;Herbel et al, 1983;Gibbens et al, 1986). When precipitation is equivalent to or greater than the long-term average, grazing activities, rather than shrub dominance, may have greater impact on recovery of indigenous herbaceous species (Warren et al, 1996).…”