陇东果园春季晚霜冻特征及防御措施

Characteristics and Defense Measures of Late Frost and Freezing in Longdong Orchards in Spring

对甘肃省陇东地区果园防霜进行了研究,以镇原县为代表性研究区域,基于庆阳市镇原县国家气象观测站1981—2023年气温及有霜日观测记录、陇东地区历年平均气候值为最新气候年代1991—2020年中国气象局30 a气象记录整编数据,通过数理统计,对甘肃省陇东地区的春季低温、霜冻日数、冻害程度、果园受灾等特征进行分析。结果表明:陇东地区终霜冻日主要分布在4月中旬—5月上旬,平均终霜冻日期为4月25日,春季极端最低气温呈渐低走势,晚霜冻害程度增强;陇东地区春季出现的晚霜冻,一般为混合型霜冻,降温时段通常由凌晨1时开始,持续至早晨7时,其中最低温度多出现在清晨5—7时;陇东地区苹果自露绿期至幼果期主要时段在4—5月,苹果平均开花始期为4月16日,开花盛期4月20日,开花末期4月27日,陇东春季发生倒春寒、低温霜冻的时期,正值苹果等经济林果的开花坐果期,面积最大的苹果园容易致损严重。采取的防霜技术,主要有增强树体抗寒性、推迟物候期、改善果园小气候3类常用措施,气象防灾减灾监测预警平台为陇东果园搭建了“虚拟防护网”,形成“一园一温一策”的科学防霜模式,果园会根据气象预报预警信息选择不同的防霜技术,并确定重点防霜时段,目前熏烟防霜的最佳方式为孔式熏烟桶及火墙。研究对陇东地区果园霜冻灾害防御措施的经验推广有一定的指导意义。

Taking Zhenyuan County of Gansu Province as a representative research area,based on the latest meteorological data and mathematical statistics,this paper analyzes the characteristics of spring low temperature,frost days,degree of frost damage,and orchard damage in the Longdong area of Gansu Province.The results show that although the annual average temperature in Longdong continues to show a warming trend in spring,the extreme minimum temperature in spring is gradually decreasing,and the degree of late frost damage is increasing.Especially since 2010,the late frost end time has been delayed,and the degree of fruit tree frost damage has intensified.Frost has become the most influential disaster factor in the forestry and fruit industry;the low temperature and frost in the spring of Longdong are mainly concentrated in April each year,with the latest delay until late May.Different degrees of frost will occur at different times throughout April,and April is during the flowering and fruiting period of various local forests and fruits,with the largest apple orchard suffering the most severe damage from disasters;whitening the tree body,spraying water on the canopy,irrigating the forest,and spraying antifreeze cannot effectively prevent frost damage during the flowering period,especially severe frost damage,through measures such as delaying the flowering period;The meteorological disaster prevention and reduction monitoring and early warning platform has built a‘virtual protection network'for Longdong orchards,with a scientific frost prevention model of‘one orchard,one temperature,one countermeasure’,reducing the impact of late frost damage on the Longdong fruit industry;The perforated smoking bucket and fire wall developed by the Meteorological Science Research Institute of Ningxia Hui Autonomous Region are popular among fruit farmers due to their low cost,self-produced raw materials,and convenient operation.They are currently the best way to smoke and prevent frost.