The Research Of Cultivation Technology On Almond-apricot Resistance And Avoidance Of The Coldness In Late Spring

Almond-apricot is the important ecological and economical native tree species in three-North Area,it is one of the world’s sixth big dried fruit.Almond oil content is 50～60%,and protein content is about 35%.It is a good woody resource of oil and high quality plant protein.Due to the early flowering time,almond-apricot was likely to suffer from the damage of late frost and cold current in flowering and fruit bearing stage,causing cold damage and frozen flowers and frozen fruit,resulting yield reduction even failure,which has a strong impact on almond-apricot of production and industry development.In this article,we studied the main producting areas of almond-apricot frost occurrence regularity,flowering phase of almond-apricot and frost prediction,suitable cultivation division of almond-apricot,delaying flowering of cultivation measures,and late frost resistance of cultivation measures systematically,trying to build effective technical measures to prevent from the late frost resistance of almond-apricot,and providing practical guidance for increasing the production of almond-apricot.The main results were as follows:We systematicaly studied the frost occurrence regularity in main producting areas of almond-apricot.Studiesshown that,frost is related to altitude,latitude,gradient,and exposure and has a closer relationship with altitude in main producting areas of Chifeng,Inner Mongolia and Zhangjiakou,Hebei region;under the same altitude and latitude,almond-apricot and armeniaca sibirica suffered the same damage in Chifeng region;under the same latitude(41°54’)and different altitude,namely,900～1200 m,890～900 m,and<890 m,almond-apricot suffered no,medium,and serious damage,respectively,at an altitude of 500 m easy cold,500～800 m the cold is lighter in Zhangjiakou;under the same site condition,the individuals with healthy and strong body and rich water and nutrient suffered less damage;to an individual,the upside suffered less damage,namely,the body with height>180 cm,160～180 cm,and<150 cm suffered almost no,medium,and serious damage;On the same position of an individual,the large fruits(fruit long 1.7 cm*fruit diameter 1 cm*fruit width 0.5 cm)suffered less damage than the little fruits(fruit long 0.9 cm*fruit diameter 0.5 cm*fruit width 0.3 cm).So choosing suitable planting area is very important to plant almond-apricot,which requires a certain altitude;If the altitude is too low,the plant is easy to be frozen;tree body shoulds not be too low;guarantee tree body robust growth by fertilization or pruning,to improve their ability of resistance and avoiding late frost and reduce late frost damageWe have preliminarily established the flowering and frost prediction model of almond-apricot.Through early flowering time and average daily temperature in Henan and Inner Mongolia of experimental field,we have calculated the effective accumulated temperature before flowering(102℃ and≥5℃),and used it to predict the flowering time.Finally we obtained the forecast formula of flowering and fruit stage:Flowering=Effective accumulative temperature≥102℃)∩[(Continue 7d)≥10℃];Fruiting=Flowering∩[(Continue 30d)≥20℃].Frost prediction model:Frost=(Flowering≤-2.8℃)U(Fruiting≤-0.6℃).Through the continuous validation for three years,the above two predictive models are reletively accurate providing an important theoretical basis and practical guidance for shield frost.We also divided the climate suitable regions for Almond-apricot according to eight major climate factor(30 years(1981-2010)of annual extreme maximum temperature(℃),annual extreme minimum temperature(℃),annual rainfall(mm),annual average temperature(℃),annual average minimum temperature(℃),Annual average maximum temperature(℃),annual sunshine hours(h),annual frost-free period(d)).We found that suitable region are mainly concentrated in 104 counties and cities in north China involving 233,149.71 km2 in area,followed by 66 counties and cities of the northeast area,involving 300,289.26 km2 in area,and 21 counties and cities of Shanxi province in northwest China,involving 104,192.8 km2 in area;Sub-suitable regionsmainly included 158 counties and cities from arid and semi-arid regions in Inner Mongolia,Qinghai,Xinjiang and other provinces,involving 2,585,431.03 km2 in area.The total area of suitable cultivation was 4,357,125.05 km2,the largest of which was in north west China(2,075,735.24 km2),reaching to 47.64%.We have established the technical measures of delaying the flowering of almond-apricot.Among all the measures,including covering single or double black sun-shade nets,covering grass and watering,spraying plant growth regulator,B9 and ETH indicated a significant effect.In August,October and mid to late November,spraying three times concentration of 1.5～3 g/LB9 can delay almond-apricot of flowering phase 5～12d.In the mid to late October spraying concentration of 0.1～1 mL/L ETH can delay almond-apricot of flowering phase 5～15d.We have established the technical measures of improving the freezing resistance of flower and fruit,including fertilization,spraying anti-freezing liquid,rick-smoking,spraying salicylic acid.After picking,fertilizing with 10～15 kg organic fertilizer or 1～1.5 kg compound fertilizer,could improve antifreeze rate of young fruit by 50%and reduce the harmness of late frost.Before frost,spraying twice or thrice 1,2-propylene glycol mixture of 20%or 30%,could resistant the temperature below-5℃for 5～8 h.In conclusion,the effective measures to resistant late frost of almond-apricot are as follows:first,plant the trees on the mountain slope where is difficult to stay for the cold air;second,after picking,fertiliz suitably;third,take measures to delaying the flowering;fourth,pay attention to the time of flowering and frost,predict,and take measures to improve the freezing-resistance.All the above measures could avoid and resistant the harmness of late frost and provide important technical support for the improvement of yield and the development of almond-apricot industry.