SummaryField and laboratory experiments were conducted to study if rain could wash-off pollen grains from the surface of the stigma and consequently affect the efficiency of fertilisation in loquat (Eriobotrya japonica Lindl.). Flowers of the loquat cultivar, ‘Dawuxing’, growing in the field, were emasculated, pollinated by hand with pollen of the cultivar ‘Longquan No.5’, then sprayed with water to simulate the effect of rain at –8, –4, –2 h before, –0 h (immediately before hand-pollination) , +0 h (immediately after hand-pollination), and 2, 4, 8, or 12 h after pollination. A control to which no water treatment was applied was also included in the assay. Meanwhile, additional assays were performed in the laboratory to improve the resolution of the field study by using earlier treatments. Here, treatments were performed by pollinating, immersing, and shaking a branch with flowers in a container of water in the laboratory –120, –60, –30, –0, +0, 30, 60, or 120 min before or after hand-pollination. One additional sample was immersed, shaken, then hand-pollinated, and immersed and shaken (ISPIS) again. The results showed that the numbers of pollen grains that germinated, and the percentages of fruit set, differed significantly between the –4, –2, –0, or +0 h treatments and the non-water-treated control in the field assays, especially in the case of the –0 h and +0 h treatments in which the stigmas were washed immediately before or after hand-pollination. However, the –8, 2, 4, 8, and 12 h treatments did not show significant differences from the non-treated control. On the other hand, the laboratory experiments showed that all washing treatments reduced the number of germinated pollen grains retained on the stigma, and the immersion treatments at –30, –0, +0, or 30 min as well as the additional ISPIS treatment, showed significant differences from the non-treated controls in the numbers of pollen grains retained on the stigmas. In conclusion, the results showed that adhesion of pollen grains to the stigmas in loquat was rapid and strong, and that the simulated rain treatment was not able to wash-off pollen grains completely from the stigma surface, except in the –0 h and +0 h treatments.