Identification of Key Periods of Temperature Influence on ‘Sirora’ Pistachio Nut Quality

Abstract

The methodology of r contour mapping was used in this study of ‘Sirora’ pistachio (Pistacia vera) to establish whether there are any significant relationships between fruit quality characteristics in commercial pistachio production and air temperature in the year before the harvest of the crop as measured at a nearby meteorological station. The work was done near Mildura in Australia. Blank nut percentages were found to be reduced by lower minimum temperatures in mid to late August (southern hemisphere). The percentage of narrow-split nuts was decreased by higher maximum temperatures across almost the whole growing season. Damaged-shell nuts were reduced by higher average daily minimum temperatures between 26 Nov. and 3 Feb. The technique of r contour mapping is shown to have potential as a way to provide early warning of possible quality problems before harvest and as a means of generating hypotheses for future physiological studies