Floral phenology and standardization of hand pollination of Clove (Syzygium aromaticum (L.) Merr. & Perry)

Clove (Syzygium aromaticum (L.) Merr. & Perry) has a rich history and is highly valued for its culinary and medicinal uses. However, its limited genetic diversity and tendency for self-pollination pose challenges for optimizing its cultivation in India. Hybridization becomes imperative to broaden its genetic spectrum. This study, hence, focuses on refining techniques related to floral biology, pollen management and artificial hand pollination in clove. The study revealed that anthesis in clove occurs from 2:30 PM to 6:30 PM, with peak flower opening between 3:30 PM and 5:30 PM. Each flower possesses an impressive array of stamens ranging from 167 to 343 and anther dehiscence begins 36 h before anthesis and continues until the day of anthesis. Pollen grain dimensions show a polar diameter ranging from 17.06-18.22 ?m and an equatorial diameter ranging from 19.40-20.70 ?m. Stigma receptivity extends from the second to the sixth day of flowering, peaking on the fifth day. Emasculation is recommended 36 h before flower opening. Maximum pollen viability and fertility are observed 12 h before flower opening. Thus, pollen collection for pollination is standardized at this time. Drying pollen at 50 °C and storing it at 7 °C in a refrigerator maintain maximum viability after 60 days while drying pollen at 45 °C and storing it in a desiccator ensure maximum fertility. Artificial hand pollination results in a fruit set of 28.87 %. Artificial hand pollination results in a promising fruit set of 28.87 %, underscoring its efficacy in enhancing clove cultivation.