REPRODUCTIVE AND VEGETATIVE CHARACTERISTICS OF PECAN CULTIVARS

Staminate and pistillate flower maturity of 80 cultivars of young (<15 years old) pecan [Carya illinoinensis (Wangenh.) K. Koch] trees are p resented. These patterns show that pollination and receptivity windows within the flowering season can be divided into very early, early, mi d, late, and very late season protandrous (Type I) and protogynous (Ty pe II) types. This system therefore provides a seasonally based 30-cla ss Type I and Type II alternative to the standard two-class Type I and Type II system, thus offering enhanced resolution of flowering interv als and an improved means of selecting cultivars to ensure cross-polli nation of yard and orchard trees. Scott-Knott cluster analysis of budb reak, nut ripening date, and date of autumn leaf drop segregated culti vars into one of several categories.