有关资料分析表明：杏、李树花期日平均气温＞２０℃且持续３天以上的年份为丰产年；花期气温降至０℃以下时，即是只有两天，杏、李树也会受冻害而减产。杏、李树一般在３月中下旬开花，有些品种花期更早。据方城县近３０年气象资料统计结果，４月中旬有１０天日最低气温＜０ The data analysis shows that: apricot, plum blossoms daily average temperature> 20 ℃ and lasts for more than 3 days for the high yield years; flowering temperature dropped below 0 ℃, that is, only two days, apricot, plum trees will be frost damage And cut. Apricot, plum generally flowering in late March, some varieties of flowering earlier. According to the statistical data of meteorological data of Fangcheng County for nearly 30 years, the minimum temperature of day <10 in mid-April <0