Studies On Growth And Development Of Apricot Flower And Fruit

Apricot is a deciduous tree of Armennica, Prunoideae, Rosaceae. People enjoyed as its delicious, juicy and nutritious fruits. Apricot tree originated from China. It had been cultivated and utilized widely in China 1400 years before. However, the cultivation size of the tree was not large enough among that of whole fruit trees. The reason why apricot development so hard were its uneven and low yield as its imprecise cultivation mostly in China before, or the yield was reduced extensively, even no yield at all, resulted by freezing injury to the flower buds, flowers, and even juvenile fruits, as the trees were sensitive for low and changeable sharply temperature in spring. A great economic benefit could be achieved if they were cultured in greenhouse and cultivated with modern scientific techniques. Apricot tree is a later tree in greenhouse cultivation. The studies on fruit development of apricot in open field had been reported by Yu Xizhi, Wang Honghua et al. The studies on flower and fruit growth and development of apricot tree in greenhouse, however, were not reported till present, though they were helpful to establish high quality efficient cultivated technology system and NCS system, to tap potentialities for apricot cultured in greenhouse. We observed and analyzed blooming phenophase, blossom types, flower drop and fruit drop, fruit development of "Gold sun"apricot between inside and outside the greenhouse in Yangling Shenfeng Company in 2002 to 2003. The results showed that: 1. Under greenhouse cultivated conditions, date of bloom beginning of apricot "Gold sun"was advanced for 33 days, blooming period was prolonged for 4 days. Ratio of complete flowers was reduced for 33.25% than that in open field. Significant different existed (a=0.01) by variance analysis. 2. The order of complete flower ratio on blossom shoot (BS) was the shorter BS>the shortest BS>the mean BS>the longer BS when cultured inside greenhouse, was the mean BS>the longer BS>the shorter BS>the shortest BS in the open field. 3. In greenhouse, flowers of apricot "Gold sun"dropped mostly incomplete blossom at early stage, infertile flowers first and partly infertile flowers later. Flowers dropped after dropping peak were complete blossom mostly, 80% of them dropped because their pistils withered and ovaries undeveloped. The apricot has twice physiology fruit drops. The first is in the first high-speed growing stage. The second is in the slowly growing period, a stage of apricot-stones are hardening. 4. Under greenhouse cultivation conditions, the fruit development period was prolonged for 15 days as the fruit growth time was prolonged of the first quick growing period and the second, was shorten of the stone-hardening period. 5. Of greenhouse culture, regression relationships on vertical diameter ,horizontal diameter and fresh weight of the apricot fruit were Y=0.42x3.39(r=0.98 ﹡﹡), Y=0.09z4.23(r=0.99﹡﹡) respectively. Relationship on fresh weight and growth days of the apricot fruit in greenhouse is Y = 1 +17e45.315.?401.06x(r=-0.99﹡﹡). 6. Under greenhouse cultivated conditions, growth ratio of the apricot in the first high-speed growing period is smaller significantly than that in open field. The accumulative growth of the apricot in the second high-speed growing period is larger significantly than that in open field. The lower temperature at night inside greenhouse should be responsible for the longer of first high-speed growing period, the slower growth and the larger fruit size.