Further Studies on Pollination of Packham's Triumph Pears

SummaryThe availability and transport of pollen for fertilization of Packham's Triumph pears was studied in a commercial pear orchard at Doncaster East, Victoria, Australia. Parthenocarpy was found to be of importance in this variety. Temperature and humidity conditions during the trial period were conducive to ripening and dehiscence of the anthers and to high bee activity. Bees formed almost 53% of the insect visitors and were the most effective means of transport of pollen from flower to flower. Enclosing trees in bee-proof cages did not significantly lower fruit set or yield but reduced the mean number of seeds per fruit from 4·5 to 0·1. Airborne pollen concentrations inside and outside the cages were similar.Simulated pear nectar containing only about 7% of sugars was less attractive to bees than simulated apple nectar (about 23% sugars), and the total sugar concentration was more important in this respect than the proportion of sugars in the nectar.