Physiological Perspective of Starch as a Carbon Source in Two Varieties of Carya illinoinensis Koch in Northern Mexico

The study took as a purpose to determine the Total Carbon (TC) content in the biomass, the Starch Carbon fraction (SC) and its annual dynamics in the biomass of perennial organs (stem and root) in adult trees of two of walnut tree (Carya illinoinensis). Four adult Western and Wichita tree stem and root samples were carried out monthly for a whole year. The TC was determined with an elemental analyser and the SC has gotten based on the molecular mass of the glucose (0.40 gC/gGlucose). t-Student test was performed between varieties per organ for the comparison of TC and SC through the program SPSS 15.0 with a significance of p ≤ 0.05. The results in Western variety were 160.02 kg TC and 4.90 kg SC to 7.54 kg SC in the stem; 64.58 kg TC and 1.74 kg SC to 3.09 kg SC in the root; in Wichita variety were presented 119.72 kg TC and 4.49 kg SC to 6.83 kg SC in the stem; 45.72 kg TC and 1.35 kg SC to 2.75 kg SC in the root. The root was the organ where the greatest amount of SC was stored in relation to the stem, due this latter constitutes a transport organ. Temperature has a marked inversely proportional influence on the accumulation of SC in both varieties. Global solar radiation and solar radiation proportionally influence the accumulation of SC.