SEASONAL EFFECTS ON GUAYULE RESIN COMPOSITION

Rubber and resin levels in guayule line N396 were monitored on a whole-shrub basis from January through July 1984. This sample interval included the period of cold-weather stress associated with rubber formation and the period of renewed vegetative growth. monthly levels were also determined for selected resin components. Fatty acid triglycerides were most abundant (> 8000 ppm) in January, with lower levels (2300-4400 ppm) in succeeding months. Triterpenoid levels showed relatively little variation (1700-2500 ppm for argentatin A). Sesquiterpene esters were most abundant in March (3600 ppm for guayulin A) and July (2900 ppm) and least abundant in April and May (< 50 ppm). These variations have direct implications for shrub processing and byproduct applications.