Dissection of Pistachio Fruit Development Towards Optimal Shell Split and Kernel Quality

Abstract: Pistachio (Pistacia vera) shell splitting is a physiological process of high market value. The industry needs to determine the timing of shell splitting and hull breakdown, in order to reduce postharvest sorting cost. Controlling the rate of early splitting and/or non-splitting nuts in combination with insuring hull integrity is of great economical value by reducing the loss of product from pest and pathogens and increasing marketable yield. Currently there is no detailed anatomical, structural and morphological description of pistachio fruit development, and the physiological and molecular mechanism of the pistachio shell and hull splitting remains unclear. We aim to establish anatomical/morphological indicators for the process and timing of shell and hull splitting for the industry to use in order to improve fruit quality and postharvest practices. We will build a model of shell split ratio as a function of accumulative thermal units, forecasting the timing of harvesting. Our long term plan is also to develop non-invasive tools to visualize pistachio kernel and overall development and monitor the abnormity of kernel development due to insect infestation.