A MODEL FOR PREDICTING PECAN PRODUCTION UNDER ARID CONDITIONS AT HIGHELEVATIONS

A multiple regression model (R-2 = 0.945) was developed from historica l data, 1971-92, to predict pecan [Carya illinoensis (Wangenh,) C,Koch ] production in an arid climate at high elevations, Dependent variable s were year of production as a measure of production tr end, number of degrees below 0.6 degrees C following Budbreak as a measure of late s pring freeze injury, and number of degrees below 0.6 degrees C precedi ng nut maturity as a measure of early fall freeze injury, Year of prod uction was the dominant factor influencing production. Freezing temper ature following budbreak had about two times more effect on production than freezing temperature preceding nut maturity. Pecan production un der arid conditions at high elevations depends on fewer variables (thr ee) than previously shown for humid conditions (eight variables).