Oppenheimer's work focused particularly on the introduction, cultivation, and breeding of tropical and subtropical fruit species suited to the climatic conditions of the
Mediterranean and semi-arid environments. It contributed significantly to the development of fruit agriculture in Israel. His research included: • Introduction and acclimatization of tropical fruit crops to Israeli climates • Breeding and hybridization of new fruit varieties • Studies on horticultural techniques for subtropical species Beginning with his arrival, Oppenheimer planted and managed acclimatization gardens in
Rehovot and
Degania Alef, which he established in honor of the sixtieth birthday of Dr.
Arthur Ruppin. Throughout his career he carried out this work in cooperation with local researchers, nursery growers, and orchard growers. Prof. Oppenheimer conducted many and diverse studies which resulted in creation of new varieties of fruits and vegetables, including:
Citrus fruit – creation of new varieties through hybridization; investigation of the composition of Shamouti oranges.
Creation of varieties of deciduous fruit trees – by crossing foreign varieties and local types he mixed planting of varieties of
apples,
pears,
plums, and
almonds. He developed fruit-tree cultivation in the
Arava and the
Sea of Galilee region. One of his key successes was the hybridization of an early-ripening apple variety requiring relatively few chilling hours, which he named “Vered”, after his daughter. He founded and developed the
subtropical fruit tree industry in Israel. Among other achievements, he contributed to the acclimatization of
avocado, cherimoya, persimmon,
guava, and
mango trees. In 1950s he discovered a new variety of mango which he named the Maya, in honor of his wife, Maya. The variety is noted for its very juicy flavor. He also made major contributions to the propagation and development of
banana cultivation as well as the
date palm industry. In addition, he worked on improving various vegetable crops, particularly adapting
tomatoes for cultivation in the hot regions of Israel and in the Arava. He participated many international conferences and consulted with agricultural research institutions in many countries, including in India, Africa, Italy, England, Spain, France, Sweden, Belgium, Germany, the Netherlands, the United States, Australia, and New Zealand. == Awards and recognition ==