Hand pollination of global crops – A systematic review

• Published in: Basic and applied ecology Vol. 56; pp. 299 - 321
• Main Authors: Wurz, Annemarie, Grass, Ingo, Tscharntke, Teja
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 01.11.2021
• Subjects: Agricultural production; Artificial pollination; Biodiversity conservation; Crop systems; Ecosystem service; Fruit set; Insect decline; Manual pollination; Pollination failure; Pollination limitation; Crop systems; Biodiversity conservation; Fruit set; Agricultural production; Pollination failure; Manual pollination; Ecosystem service; Artificial pollination; Insect decline; Pollination limitation
• ISSN: 1439-1791
• DOI: 10.1016/j.baae.2021.08.008

Global pollinator declines and land-use change can lead to pollination limitation with implications for agricultural productivity. Hand pollination is used in agricultural production as a technique to manually pollinate crops. But the prevalence of hand pollination, as well as benefits and costs, remain unknown. We systematically reviewed the literature for examples, methods, drivers, and economic motivations of hand pollination. Furthermore, we discuss the risks, constraints, and opportunities of hand pollination. We found evidence for 20 hand-pollinated crops, including minor but also economically important crops (e.g. apple, oil palm, cacao). The lack of pollinators was the most important reason for the application of hand pollination (50% of crops), while insufficient proportion or proximity of pollinizers (8% of crops) and skewed sex ratio or dichogamy (8% of crops) were second most important. The main economic motivations for practicing or recommending hand pollination were to increase fruit set, and/or fruit quality (78% of crops). Hand pollination is practiced in large- and small-scale farming, home gardens, and greenhouses. Opportunities of hand pollination are the control of pollen origin and quantity, pollination timing and frequency as well as independence from environmental fluctuations. Farmers can increase yields, improve fruit quality, avoid fruit abortion, increase employment, and secure subsistence food. The main constraints of hand pollination are high labor inputs, high material costs, and required skills. Major risks of hand pollination include management ignoring pollinator conservation, high food prices, over-pollination, labor accidents, and unfair labor. We conclude that in the face of global change, hand pollination allows improved control of pollination and is likely to increase in importance. The benefits of hand pollination need to outweigh the costs and fair labor is essential. Altogether, hand pollination can be a valuable tool for crop systems where pollinators are absent or are not reliable for sustaining high-quality crop production. [Display omitted] -Hand pollination is used in global commercial crop production.-It can strengthen the resilience of farm systems responding to pollination limitations.-Hand pollination allows controlling pollen identity and quantity.-Benefits include higher yields but often at high labor costs.