Bibliography: leaves 190-211.xvi, 211 leaves, [24] leaves of plates : ill. (chiefly col.) ; 30 cm.Research was carried out to evaluate pollination efficiency, gene flow by pollen and fruit set in Packham Triumph cultivar pear trees located in a mixed planting of pear cultivars in a commercial orchard in the Coromandel Valley region of South Australia.Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 199