Fruit Growth and Development of `Ideal' and `Western' Pecans

Abstract

Pecan [Carya illinoensis (Wangenh.) K. Koch] fruit development was evaluated over three growing seasons (1981-83) to determine the seasonal growth patterns in the cultivars Ideal and Western. Gross morphological stages were examined weekly in fruit dissected in cross and longitudinal sections. Free-nucleate endosperm was first observed in mid-July when fruit had grown to 50% of their final length, occurring at 67 days after stigma receptivity (DASR) for `Ideal' and 76 DASR for Western'. Maximum content of free-nucleate endosperm occurred 100 DASR in `Ideal' and 109 DASR in Western' fruit. Ovary wall Signification was completed 119 DASR in `Ideal' and 132 DASR in `Western'. At this time, nut enlargement was complete. Cotyledon thickening required 36 and 43 days for `Ideal' and Western', respectively. The time from stigma receptivity to completion of cotyledon thickening in mid-October was 13 days longer for Western' than for `Ideal'. Because of a cool spring in 1983, all stages required a longer time in 1983 than in the previous 2 years. Most aspects of fruit development were similar between `Ideal' and Western' over the 3-year study.