Pistillate Flower Bud Development in Pistachio 1

Abstract

We found in light and scanning electron microscopic studies of buds of the pistillate ‘Kerman’ pistachio ( Pistacia vera L.) that about 12 months elapsed from the time of inflorescence differentiation until the opening of individual flowers. Growth of the rachis and its lateral branches occurred from April to June; sepal differentiation, from late May to mid June; pistil initiation, from early October to March; and carpel development, from late March to early April. Cessation of the development of the inflorescence buds during July, August, and early September appears to be unrelated to nut growth and development, as buds were inactive during that period in both bearing and nonbearing trees.