Flowering and fruiting characteristics of Macadamia spp.in Xishuangbanna, Yunnan

【Objective】To study the flowering and nut set patterns of Macadamia spp. in Xishuangbanna of Yunnan, aiming to provide refeence for improving the yield and quality of Macadamia spp. 【Method】Employed the label-hanging method to observe the flowering phenology and nut setting characteristics of 12 Macadamia spp. varieties. The rate of nut set, rate of racemes with nut set, mean nut number per infructescence and abscission rate were measured to reveal the nut setting patterns in different varieties. 【Result】The flowering phenology was different in the 12 varieties. Varieties D4, O.C, 863,820 and 842 had longer flowering periods and in two batches; varieties A16, A4, Special, 828,816,508 and 246had short and more concentrated flowering periods. Obvious variations in nut set, rate of racemes with nut set, mean nut number per infructescence and abscission rate were observed among different Macadamia spp. varieties due to the influence of flowering stages and variety characteristics. And the racemes of the varieties O.C,828,863,D4 at the end flowering stage almost had no nut setting ability. The final RRNS exhibited a positive correlation with the final RNS across all tested varieties, suggesting that RNS could serve as a reliable indicator for evaluating yield. Flowering time had little effect on the average number of fruit set per infructescence of different varieties, and only 1-2 fruits were seated on each infructescence. There were serious fruit dropping in all varieties, but there was no significant difference in abscission rate among different varieties in the same flowering period(P>0.05). 【Conclusion】The harvest mode of Macadamia spp. was determined by the flowering phenology, such as the varieties D4, O.C, 863, 820 and 842 with a prolonged flowering period require staggered harvesting. Conversely, the varieties A16, A4, Special, 508 and 246 with a shorter flowering period can be harvested intensively. The racemes of the last flowering stage of the second bath had minimal fruiting ability, two batches of inflorescences of varieties O.C, 863,828 and D4 can be thinned to save the resources of mother tree.