Methods for assessing pollen release from apple flowers, cultivar differences and effects of time from anthesis

The release of pollen from flowers of 12 apple cultivars was studied using the two simple methods of scoring and weighing pollen from ten flowers. Cvs Alice, Discovery and Lobo were good pollen producers, while Quinte and to some extent Julyred and Summerred released smaller amounts. The methods described seem to give sufficient reliability for routine tests. For ‘Discovery’, pollen release as affected by time from anthesis was also studied. For indoor flowers, a marked peak in pollen release occurred 3-5 days after anthesis. Indoor as well as outdoor flowers also released pollen after ten days. The fact that all petals were shed after five days indicate that apple flowers can be valuable pollen source even after petal fall, although germination tests showed pollen viability to be poor ten days after anthesis of outdoor flowers.