Growth Rate of Sprouts after Top Removal of Huisache (Acacia farnesiana (L.) Willd.) (Leguminosae) in South Texas

Abstract

Huisache sprouts attained almost half their expected total plant height in five months after top removal in South Texas. Huisache sprouts from plants cut on three different dates in the same year showed the same general growth pattern with the inflection point on the growth curve occurring at about 60 days. Limited rainfall prior to top removal apparently affected the length of time required for sprouting after top removal. Biotic pressure significantly reduced the elongation rate of huisache sprouts to one-half that of undamaged sprouts during the initial four month growing period. Huisache (Acacia farnesiana (L.) Willd.) is one of the many woody species common in South Texas. It now occurs on about 1.1 million hectares (2.6 million acres) in Texas, mainly in the Gulf Coast Prairies and South Texas Plains (Smith and Rechenthin 1964). Huisache sprouts elongate rapidly after top removal (Powell and Box, 1967). Of the many woody species in South Texas which resprout after top removal, huisache sprouts appear to have the fastest elongation rate. This study was designed to investigate the rate of regrowth of huisache sprouts and some of the factors which affect the regrowth rate. The study area was located in the chaparral-bristlegrass community (Box 1961) on the Rob and Bessie Welder Wildlife Foundation Refuge. San Patricio County, Texas. The refuge is located in the western portion of the Gulf Coast Prairies and Marshes (Gould 1962). METHODS. Huisache sprout growth was measuredon areas shredded with a rotary mower and on untreated areas. Plants on shredded areas were cut to a 1/2 to 1 dnl 1 This publication is contribution number 128. Welder Wildlife Foundation. Sinton. Texas 78387.