Research And Extending Of Key Technology Of Protected Cultivation Of Fruit Trees

The photosynthetic, flower and fruit developing charactistic , chilling-requirement and the techniques were mainly studied of some kinds of fruit trees in greenhouse.The main results were as follows:1. The trends of photosynthesis curve of different fruit trees are similar different cultivars has different photo-saturation point and photo-compensation point .When planting fruit trees in the green house ,the higher photo-saturation point trees were firstly planted under higher PFD ,but the ones that have lower photo-saturation point were opposite.We can take several methods to improve the PFD in the green house so that photosynthetic rate will be improved .In protecting culture,low light and concentration of CO₂ are the main limiting factors of photosynthesis. The PFD in the green house is difficult to regulate ,but improving the concentration of CO₂ which can help to compensate the reduction of photosynthetic rate because of PFD reducing is easier .The diurnal changes of photosynthetic rate of the peach trees leaves in the green house reach the Pmax at 10: 00.The second Pmax is at 14: 00,The value of photosynthetic rate is lower, the photosynthesis between 11:00¹2:00 also reduced.2. Chilling requirements were significant differences from different kinds of varieties and cultivars : the chilling requirement of grape is between 1010¹840 c.u, the flower bud of peach trees are 620⁹40c.u, and the foliage buds are 500⁹10c.u; apricot are 790⁹20 c.u and 790⁹10 c.u. Moreover, the same cultivars had different chilling requirements significantly between different years, it indicated that chilling requirements not only were effected by genetic factors but also regulated by enviromental variations. The flower and foliage bud of the same cultivar have different chilling-requirement and flower buds are higher than leaf buds.Different cultivars of the same fruit trees have nonecessary association with fruit -developing period. Fewer early ripening cultivars in grape and apricot possessed lower chilling requirements, but the trend of peachis not obvious.3. 6-BAx GA3can postpone the senescence of leaves, and the time of dropping of leaves which was treated by 6-BA, GA3 was postponed 6-9 days .The fruit trees whose leaves dropped later,but germinate earlier > had a higher germination rate and lower chilling-requirement when used 6-BA. Though GA3 can postpone the dropping of leaves ,the chilling-requirement was improved . ABA, which can accelerate the senescence and dropping of leaves can help to make the time of dropping of leaves earlier 4-7 days , ABA had no obvious effect on chilling-requirement of buds.4. Flower and fruit developing characteristics: germination rate of the pollens of apricot which is in the greenhouse was more than open field .Pollens can keep higher activities germination rate in 18h after picked ,and germination rate reduced later.The temperature of blossom in the greenhouse shoud be controlled between 22-25 °C .We had better pollinate immediately while collecting pollens. Artificial pollination or bees can promote pollination and fertilization ,and improve fruit setting percentage.The smell and taste of peach in the greenhouse reduced comparing with open field5. To summarize, the efficiency technology of apricot, grape, peach in protecting-culture had an great benefit when was extended.