Shea (Vitellaria paradoxa C.F. Gaertn.) is a multipurpose tree species indigenous to the Sudano Sahelian zone of Africa and occurs as the most abundant economic tree species in northern Ghana. The edible oil (shea butter) extracted from shea kernel is ranked as the most economic product of the species. Although fruit set and yield of shea are known to be influenced by insect pollination, the actual contribution of insect pollinators to its reproductive success has rarely been studied. This study estimated the percentage insect pollinator dependence and monetary value of insect pollination per bag of shea kernel (85 kg) in the Guinea savanna zone. Open pollination and insect exclusion treatments were applied to the flowers of 18 randomly selected matured shea trees and observed from the onset of flowering to fruit maturity. Proportion of total production value attributed to insect pollination approach was used in estimating the monetary value of pollination per bag of shea kernel with the average market price as proxy. The study revealed an insect pollinator dependence of 77% and 73% for fruit set and dry kernel yield, respectively. Mean number of fruit set per inflorescence varied significantly between insect-excluded and open-pollinated inflorescences (p < 0.05). The monetary value of insect pollination was estimated at GH₵ 73.21 (US$ 18.67) per bag of kernel as of August 2016. Shea is a high insect pollinator–dependent species and the conservation of insect pollinators would be critical to the sustainability of yield.

中文翻译：

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加纳几内亚热带稀树草原上乳木果（Vitellaria paradoxa CF Gaertn。）的昆虫传粉媒介依赖性

牛油树（Vitellaria paradoxa CF Gaertn。）是非洲苏达诺萨赫勒地区的一种多用途树种，是加纳北部最丰富的经济树种。从乳木果中提取的食用油（乳木果油）被列为该物种中最经济的产品。尽管已知果实结实和乳木果的产量会受到昆虫授粉的影响，但很少研究昆虫传粉者对其繁殖成功的实际贡献。这项研究估计了几内亚热带稀树草原地区每袋乳木果（85公斤）的昆虫授粉媒介依赖性百分比和昆虫授粉的货币价值。对18种随机选择的成熟乳木果的花进行开放式授粉和驱虫处理，并从开花开始到果实成熟进行观察。昆虫授粉法产生的总产值比例用于估计每袋乳木果的授粉货币价值，并以平均市场价格作为替代。研究表明，昆虫授粉媒介对坐果率和干果产量的依赖性分别为77％和73％。每个花序的平均坐果数在驱虫花序和开放授粉花序之间有显着差异（p <0.05）。截至2016年8月，昆虫授粉的货币价值估计为每袋果仁73.21 GH（18.67美元）。乳木果是高度依赖昆虫授粉媒介的物种，对昆虫授粉媒介的保护对产量可持续性至关重要。