在宁夏地区,苹果开花期间,经常遇到不同程度的霜冻危害,使产量大幅度下降。如灵武园艺实验场,1976年就因花期霜冻,果实损失80％。十多年来,该场多采用放烟法予防霜冻,但收效甚微。 1977年该场开始和宁夏水科所合作,进行喷灌防霜试验。78年5月,建成固定管道式喷灌区36亩,采用吉林通化塑料厂的工农—4型低喷灌强度喷头(喷水量2米~3/时)。5月10日,当国光 In Ningxia, during the flowering of apple, frost damage is often encountered to varying degrees, so that the output dropped significantly. As Lingwu horticultural experimental field, frost in 1976 due to flowering, fruit loss of 80%. More than a decade, the field more to use anti-smoke law to prevent frost, but with little success. In 1977 the field began to cooperate with Ningxia Institute of Water, anti-frost sprinkler test. In May 1978, 36 mu of fixed-pipe sprinkler irrigation area was built, and the worker-peasant-worker-peasant-4 type low sprinkling intensity sprinkler (spraying water volume of 2m ~ 3 / h) at Jilin Tonghua Plastic Factory was used. May 10, when the country light