Abstract:

Based on the experiment data and meteorological data from 2014 to 2016 on the different elevation orchard in "Hua Niu" apple producing area in southeast of Gansu province, the dynamic growth model of apple was established, the dynamic change characteristics of "Hua Niu" apple growth and its correlation with heat factor were analyzed. The results showed that the apple diameter growth and single fruit weight may be described with Logister curve, fruit growth had the obvious time characteristic, the extreme value change and growth regular. The horizontal diameter was greater than the longitudinal diameter in early growth of young fruit until early to mid July；the fruit diameter maximum value appeared in the mid to late June, weight of single fruit maximum value appeared in early to mid July. Each additional 100 meters above sea level, the data of the maximum value delayed about 4 days. The fruit diameter and weight reached the maximum in stage 2 during stage 4 of fruit growth，the fruit pulp cells increased rapidly in stage 2 (45-80d after flowering，about from mid June to mid of July). There was an obvious correlation between the average temperature and the growth of fruit weight. The variation relation between fruit diameter, single fruit cumulative weight and ≥10℃ accumulated temperature can be imitatived by S curve. The fastest time of fruit diameter growing was in June 20 or so, for about 50 days after flowering and the fastest time of single fruit weight increasing was in July 6 or so, for about 66 days after flowering. Strengthen the management of water, fertilization, diseases and insect pests, pruning in the critical moment during fruit growth is an important part to improvement the apple yield and commodity level.

Key words: "Hua Niu", apple, Dynamic growth characteristics, Heat factor, Correlation analysis