Youth tree behavior of olive (Olea europaea L.) cultivars in Wudu, China: Cold and drought resistance, growth, fruit production, and oil quality

The wet, hot summers and cold, dry winters in Wudu, China differ from the climate in the Mediterranean olive-growing region. Eight olive (Olea europaea L.) cultivars ('Arbequina', 'Hojiblanca', 'Manzanilla de Cacereña', 'Cornicabra', 'Picual', 'Arbosana', 'Koroneiki', and 'Empeltre') were grown in Wudu and evaluated for 5 years after planting. We evaluated the behavior of the youth trees, including their cold and drought resistance, tree growth, oil content, fruit characteristics, fruit production, and oil quality. The results showed that 'Empeltre', 'Picual', and 'Arbequina' were the most cold-resistant cultivars, while 'Arbosana' was the least cold resistant. 'Empeltre', 'Hojiblanca', and 'Koroneiki' were the most drought-resistant cultivars, while 'Arbequina' and 'Arbosana' were the least drought resistant. 'Empeltre' and 'Picual' showed the most vigorous tree growth, and 'Koroneiki' and 'Arbosana' grew slowest. The oil contents of cultivars before harvest ranged from 33.61% ('Cornicabra') to 50.09% ('Arbosana'). The fruit productivity was highest in 'Arbosana' and lowest in 'Empeltre'. The olive oils of all cultivars were EVOO (extra virgin olive oil) according to the IOC (International Olive Council) standard, but 'Empeltre', 'Hojiblanca', and 'Cornicabra' had higher linolenic acid contents in oil. We concluded that 'Arbosana' was the cultivar with the greatest potential for cultivation in Wudu. It had the highest fruit production and oil content even in the smallest trees, its EVOO quality met the IOC standard, and it was suitable for growth in areas with abundant water and without continuous frost below −4 °C. We concluded that olive trees grow faster in Wudu than in Mediterranean regions, but have lower cold resistance and olive fruit production in Wudu. These results show how olive cultivars can flourish in a new environment and provide an important basis to expand the cultivation of these cultivars to other suitable regions in southern China.