Carbohydrate Reserves in Roots of Sand Shin Oak in West Texas

Abstract

Total nonstructural carbohydrate (TNC) concentrations in the root system of sand shin oak (Quercus havardii) were analyzed from January, 1972, through December, 1973. Effects of shredding on root reserves were also explored. In both years root TNC varied with the different phenological growth stages. Reserves were gradually depleted throughout the dormant season, November to April, until the low of 6.5 and 7.0% was reached in early May of 1972 and 1973, respectively. TNC then began to accumulate in the roots when the leaves were from 1/3 to 1/2 full size. Shredding significantly reduced root reserves for 6 months. Early leaf expansion is a good indicator of downward carbohydrate translocation and may be the best guideline available for the application of systemic herbicides to effect oak control.