Male performance in pistachio (Pistacia vera)

Pollinator performance was evaluated in a collection of 17 male and 37 female pistachio clones from Cyprus, Greece, Iran, Israel, Syria, Tunisia and USA. Flowering time, pollen quantity and pollen quality were evaluated. The flowering dates of the clones spanned one month and covered the flowering time of the main female cultivars. Pollen quality, evaluated as in vitro pollen germination, was high in all the studied clones, averaging 85 %. However, big differences existed in pollen quantity, measured both as inflorescence density and as pollen per inflorescence. Thus, the amount of pollen per inflorescence averaged 173 mg and ranged from 73 mg to 252 mg. The fact that flowering time and pollen quantity were the two most variable characters between clones, but were constant over years, together with the fact that they are two characteristics easily measured in the nursery makes them good criteria for pollinator selection in this species.