Phenological Characteristics and Flowering Synchrony of Vitellaria paradoxa in the Dry-hot Valley of Yuanjiang, Yunnan

Purpose The shea tree (Vitellaria paradoxa C.F.Gaertn.) is an important woody oil plant native to Africa. It was introduced to Yunjiang County, Yuxi City, Yunnan Province, China in the 1960s. This study seeks to record phenological observations on the introduction of the shea tree into China and its domestication as well as examine the factors that allowed it to flourish across the dry-hot valleys of southwest China.

Method Leafing, flowering, fruiting and flowering synchronization across 100 shea trees planted in the dry-hot valley of the Yuanjiang region were observed and analyzed.

Result Leaves clustered at the top of each branch, turning dark green when mature and leaf replacement occurred throughout the year. Shea tree flowers, with ovate-lobed corolla and white petals when mature, clustered similarly to leaves. The flowering period lasted approximately six months, beginning in early March and ending in early August. Bright green was the typical color of ripened shea fruit, and the average weight of each fresh fruit was between 22.04 g to 24.56 g, while the average fresh kernel weight was between 8.128 g to 8.932 g. Similarly, the fruiting period lasted approximately six months, from the end of March to the end of October.

Conclusion This research reveals that shea trees feature a high degree of flowering synchronization at both individual and population levels. Comparing the specimens from Yuanjiang to African, we found that there were no significant differences across biological characteristics, and the duration of leafing, flowering, fruiting phenological phases were basically consistent as well. This study is highly informative and instructional in the introduction, domestication and artificial cultivation of shea trees.