龙眼与其它果树一样,在授粉受精后都会发生一定数量的落果现象.然而,1990年我省龙眼产区一反常态,从云霄、诏安到主产区同安、泉州、莆田等地,相继在5月初至5月下旬发生大面积异常的落果,并造成产量明显下降,为探明其落果原因,我们对有关产区进行调查,并作如下初步分析. Longan and other fruit trees, pollination and fertilization will occur after a certain number of fruit drop However, in 1990, our province longan producing area uncharacteristically, from the sky, Zhaoan to the main producing areas Tongan, Quanzhou, Putian and other places, one after another in early May Large-scale anomalous drop-off occurred in late May and caused a marked drop in output. To find out the causes of its drop-off, we conducted a survey on the relevant producing areas and made the following preliminary analysis.