|Grauke, Larry - L J|
Submitted to: Fruit Varieties Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/1996
Publication Date: N/A
Interpretive Summary: Pecan trees have complex systems of flowering. This paper describes the male and female flower parts that mature at different times on the same tree. To insure pollination (which is necessary for nuts to form), the male flowers of some trees have to shed pollen while female flowers on other trees are mature. Patterns of flowering have been studied in different locations for several years. We wanted to learn if patterns of flowering are the same in different years, or if patterns vary in different years. In years of warm spring weather, trees flower earlier than in years of cool spring weather. The overlap of flowering between two types of grafted pecan may also vary in different years. The observations made in this paper may effect how we use published reports of pecan flowering, and how we design orchards to insure efficient pollination.
Technical Abstract: Pecan dichogamy data from several years and several locations were studied. At a given location, different seasons show variability in the inception and duration of bloom. The seasonal timing of flowering is controlled largely by temperature, with warm seasons resulting in earlier bloom than late seasons. From year to year, the flowering period of a cultivar varied din relation to the flowering periods of other cultivars. To best estimate a cultivar's season of bloom, records should be averaged over several years. To insure adequate overlap of pollen shed and pistil receptivity, multiple cultivars should be included in the orchard to provide early-, mid-, and late-season pollen, with receptivity of the key cultivars of the orchard being heavily targeted. Given the variability of cultivar performance at different locations, the most reliable information will be obtained closest to the orchard site in question.