The Biological Characteristics of Flowering and Fruiting in Acacia confusa

The flowering and fruiting conditions of 20−23 aAcacia confusa were investigated in 2017−2018 for consecutive 2 years by field observation. The biological and reproductive characteristics were studied. The results show that:The flower bud ofA. confusa formed in late March, the middle and late period of mid- April came into the first flower stage, and the peak period was reached in the end of April. The flowering period of the colony was over in late May, the duration of the whole flowering period was about 40 d. After the end of colony flowering, the floret period entered into a sporadic floret period of about 40 d. The young fruit appeared early in late April. In late July, the fruit was ripe and the whole fruit growth period was about 90 d. Inflorescence usually opens at night. When pistil begins to expand and mature before stamen, pistil is prematured. The stigma of flowering is highly active at 14: 00 to 16: 00 on the day. It is recommended that pollination be done in this time period. The pollen viability of flowering on the day was as high as 97.64%, the amount of pollen dispersed in sunny days was significantly higher than that in other weather, and it continued at a high level (above 80%) after the peak. Therefore, it is recommended to collect pollen on a sunny day during pollination. The natural pod rate of A. confusa is relatively low, and the natural pods rate for 2 consecutive years is less than 25%. The seed quantity of pod is mainly 6 grains, followed by 7−8 grains, and rarely 2−3 grains;The number of shrivelled seeds increased with the number of seeds contained in the pod.