Effects of Hydrogen Cyanamide on Bloom Advancement in Female Pistachio ( P. VeraL.)

Abstract

Inadequate pollination in pistachio trees is usually due to the unstable period (delayed and/or prolonged) of blooming of the female trees, especially in areas with mild winters, as well as to the absence of the middle and late flowering Pistacia verapollinators. Spraying female trees with hydrogen cyanamide during the their rest period advanced bloom by about 19 days. This advance was sufficient to allow overlap with both P. vera‘B’ and ‘C’ in areas with mild winters and P. terebinthusand P. vera‘A’ in cold region orchards where the middle and late flowering pollinators are usually absent. Using hydrogen cyanamide as a dormancy breaking agent the female trees produce commercial yields.