Evaluation Of Adaptability And The Research About Postponing Florescence Of Almond-Apricot In Baiyushan Hilly Area

The main problems of almond-apricot trees in Baiyushan hilly area of northern Shaanxi that only blossom and no fruiting had been unveiled. Almond-apricot florescence and setting fruit phase encountered strong and much frost, and the frosts were very easy to injury the flower and young fruit. Dominating variety was Longwangmao, that grew slowly and its florescence was shorter and earlier than other varieties, and resisted frost weakly. Most almond-apricot orchards had been built in southern slope land, southeastern and southwestern slope land, in these slope lands almond-apricot florescence were shorter and earlier than other slope land, very easy to encounter frost. Most trees shape had been trained open center shape, setting fruit positions were relatively lower, and most fruiting branches were spur branch and short branch, so the florescence was shorter, earlier and centralization, all these not benefited the flower and young fruit to avoid the frost. In flat land when a big orchard had been built several years, autointoxication would be thrown out and almond-apricot orchard soil nutrient was very infertile.In Baiyushan hilly area, the roots of almond-apricot horizontally distributed from 50cm to 180cm around the trunk and vertically distributed in subsoil from 30cm to 80cm principally. The roots had three growing peaks in a year and July-peak was the tallest peak. Extending shoots had two growing peaks and fruit shoots had one growing peak in a year. Fruiting percentage of almond-apricot was 15.61% when florescence and young fruit term didn't meet frostbite, or fruiting percentage was about 0.63%. The course of fruit growing showed "slow-fast-slow-fast" liking "double S". In this region almond-apricot didn't have abscission of fruits before maturity. 100kg fruits of almond-apricot could produce 12.6kg stone and 3.6kg almond. The florescence of sunny slope-land was earlier then shady slope-land , and low land was earlier then high land. On account of frostbite, almond-apricot had little yield in many years.Compared with local apricot of table apricot, wild apricot and Siberian apricot, the florescence of almond-apricot was the earliest and the shortest, the number of no harvest year caused by frost was the most, number of roots was the least, roots distribution was lowest and narrowest, trunk diameter, height, crown diameter were the least. Its almond was changed smaller and smaller with the tree's age increased;production of stone was lower than wildapricot and Siberian apricot. In small hilly region and medium mountain region I ,almond-apricot production value was lower than table apricot, and higher than wild apricot and Siberian apricot. In medium mountain region II, almond-apricot production value was lower than wild apricot and Siberian apricot, and very lower than table apricot. Almond-apricot couldn't be a dominating species in Baiyushan mountainous area.When the ground of almond-apricot orchard had been covered with single sunshade net, double sunshade net and grass in spring early , the soil surface temperature and 30cm soil temperature had been declined, 0~ 100cm soil humidity had been relatively increased, florescence, sprouting and others of almond-apricot had been delayed and florescence had been prolonged. These treatments were very advantage to florescence and fruiting to avoid frost. The fruiting rate of almond-apricot that the ground covered with single sunshade net, double sunshade net and grass were 3.93, 5.50 and 6.62 times of almond-apricot that the ground not coveredIn order to prevent frost and postpone florescence, single and double sunshade nets had been used to shade the trees in spring early before florescence. Compared with no shading, illumination intensity in sunny days had been reduced by 56.15% and 87.37% respectively, and 51.33% and 72.05% in cloudy days;surface soil temperature had been reduced by 3.86 "C and 5.42°C, soil temperature in the depth of 30 cm had been reduced by 1.01 "C and 1.44 °C, air temperature had been reduced by 1.50°C and 2.40"C respectively;wind speed had been decreased 50.00% and 66.67% respectively;air relative humidity had been increased 15.09% and 20.75% respectively;0-100 cm soil gravimetric water content had been increased 14.88% and 26.95% respectively;phonological phase such as florescence, sprouting and others had been delayed 4 and 5 days, florescence had been prolonged 1 and 2 days, and fruit setting rate had been increased 7.95 and 10.25 times respectively.Because almond-apricot florescence was earlier, florescence and fruiting phase encountered strong and much frost, and the frost was very easy to injury the flower and young fruit that made the almond-apricot reduced yield or had no yield. Almond-apricot grew weakly and production value was lower than other Armeniaca species, almond-apricot couldn't be a base construction species in Baiyushan mountainous area, and only could be regarded as a subordinate species. In order to increase the production value of present almond-apricot, the ground of almond-apricot orchard could be covered with grass, and the trees could be shading by single and double sunshade nets in spring early before florescence, so the florescence could be delayed and prolonged, fruit setting rate could be increased.