Optimum time for hand pollination in yam (Dioscorea spp.)

Area of Science:

• Agricultural Science
• Plant Breeding
• Horticulture

Background:

• Low hand pollination success rates in yam (Dioscorea spp.) hinder breeding programs.
• Suboptimal weather conditions are a contributing factor to reduced pollination efficiency.
• Identifying optimal pollination timing is crucial for enhancing yam hybridization.

Purpose of the Study:

• To determine the most suitable month, week, and hours for hand pollination in yam (Dioscorea rotundata and Dioscorea alata).
• To improve pollination success rates within yam breeding programs by optimizing timing strategies.

Main Methods:

• Continuous hand pollination was conducted over two years within the flowering windows of D. rotundata and D. alata.
• Pollination success was analyzed based on crossing hours, weeks, and months.
• In vitro pollen germination tests were performed to assess pollen viability at different collection times.

Main Results:

• Morning hours (8 a.m. - 12 p.m.) showed higher pollination success in D. alata, while mid-day was optimal for D. rotundata.
• Pollination success rates varied significantly across weeks and months for both species, with specific periods being more conducive.
• Mid-day pollen collection (12 noon - 2 p.m.) yielded better in vitro germination, though genotypic effects were notable.

Conclusions:

• Specific times of day, weeks, and months significantly influence yam pollination success and seed production efficiency.
• Focusing hybridization activities during identified optimal periods can enhance breeding outcomes in yam.
• Understanding pollination time dynamics is key to improving yam breeding program efficiency.