杏及苹果等果树一年开两次花的现象是常常看到的。这是不正常的现象。有时杏或苹果,在春季开花前或开花时遭受冻害,使花开不好,或落花、落果,甚至当年不能结果;有时由于虫害,在春季把叶及花吃光;或者由于病害,枝叶生长很弱;这样,本来供给开花着果及枝叶生长的营养物质,不能充分利用,因而在当年形成的花芽,遇到外界适宜的环境条件, Apricots and apples and other fruit trees open twice a year flowers are often seen. This is an abnormal phenomenon. Sometimes apricot or apple, frost damage before flowering or flowering in spring, poorly blooming, or falling or decolourating, even unable to produce the same year; sometimes the leaves and flowers are eaten in the spring due to pests; or because of diseases, foliage growth Very weak; In this way, originally provided for the flowering fruit and foliage growth of nutrients, can not make full use of, and thus formed in the bud that year, meet the outside world suitable environmental conditions,