Research On Water Requirement Pattern Of Apple Tree At Arid Hilly Region In The Loess Plateau

In order to provided a scientific basis for precision irrigation of apple orchard, 6 years Fuji apple tree was used as the research object in Northern Shaanxi Mizhi, with apple tree phenology of the period, by field capacity as the standard to moisture regulation, analyzed the effects of different irrigation amount on the growth, development, yield and quality of apple trees in the mountainous area, defined arid mountain apple in different phenological phase appropriate irrigation amount, revealed in mountain areas of Northern Shaanxi apple tree water requirement rules. The main conclusions follows:(1) With soil moisture increasing, the germination and fruit setting of apple are first increased and then decreased. Suitable irrigation for germination rate and setting rate of apple trees was 61.6% and 62.92%, respectively, compared with CK, increased by 27.8% and 20.8%. With soil water content decreasing, shoot growth, heavy blinds, leaf area, relative water content and water retention capacity gradually decreased, the leaf water saturation deficit will be increased, and the water too high or too low is increase by average thickness of the blade.(2) Moderate water deficit is benefit for fruit coloration, improving fruit firmness and Soluble Solids content, reduces fruit water content. The pulp water content were higher than peel, on average 5.1% higher. With the increase of moisture content, the average fruit weight, fruit shape index, fruit water content increases, the maximum value compared with CK respectively increased by 11.3%, 1.7%, 6.2%. The optimal excellent fruit rate were 92.4%, compared with CK were increased by 45.2%. With the production increasing, irrigation amount gradually increased, income also increased, but excessive water is supplied, reduced apple production, income is also reduced, the highest yield was 12760.0 kg?hm-2, compared with CK, its production enhanced by 33.3%, revenues increased by 46.9%. With irrigation amount increasing, use efficiency is reduced.(3) 6 years Fuji apple growing water requirement is 571.54 mm at arid mountain in Northern Shaanxi, in which sprout period, flowering period, new shoot growth and young fruits development period suitable soil water content of field capacity was 50~60%, but fruit swelling period and mature period was 70%~80%. Sprout period, flowering period, new shoot growth and young fruits development period, fruit swelling period and mature period of water requirement are 67.50 mm, 37.20 mm, 180.63 mm, 218.63 mm and 67.58 mm. In general hydrological year, optimal irrigation amount of apple tree is 216.91 mm, which of sprout period 56.50 mm, flowering period 22.20 mm, new shoot growth and young fruits development period 92.63 mm, which in initial shoot growth period, new shoot rapid growth period, new shoot slow growth period, initial young fruit development period and young fruit enlargement period, respectively appropriate supplementary irrigation 16.74 mm, 68.29 mm, 7.59 mm, 2.87 mm and 14.59 mm. Initial fruit enlargement period, fruit enlarging period, fruit slowly swelling of rainfall can meet water requirement of apple trees, without irrigation. Suitable supplemental irrigation amount of maturity is 45.58 mm.The research results indicate that according to the growth period of apple tree in different phenological stages, used for apple trees need rules of water supply of water, not only ensure high yield and quality of apple in Loess Plateau hilly region of arid mountain, but also water conservation and improve the limited water resources utilization. It is important significance for improving quality and performance and promoting the sustainable development of arid mountain apple orchard in the Loess Plateau.