Managed pollination is a much better way of increasing productivity and essential oil content of dill seeds crop

Abstract

Dill seeds (Anethum graveolens L.) is the most valuable medicinal seed spice crop of Apiaceae. It bears small yellow flowers in the form of umbels. Being a cross-pollinated crop, floral visitors play vital role in pollination and seed sets. Hence, the present study was conducted at the ICAR-National Research Centre on Seed Spices, Ajmer (Rajasthan), India to discover the pollinator's community, foraging behaviour and abundance of most frequent pollinators and different modes of pollination on seed yield and quality of this seed spice crop. The insect visitors community of dill seeds was composed of 28 insect species belonging to 14 families of 6 orders. Most of floral visitors started their foraging activity at 8.00 h, reached peak activity between 12.00 and 14.00 h and their activity ceased at 18.00 h. Apis florea, A. dorsata, A. mellifera, solitary bee, Halictus sp. and two unidentified species of Hymenoptera; Episyrphus balteatus (DeGeer), Episyrphus sp., Eristalis sp and two other Musca species of Diptera were identified as potential and regular floral visitors of dill seeds. The highest seed yield of 1505.63 kg/ha was recorded in the treated plots provided with only 10% jaggery solution and was at par with the open pollination. A lower seed yield of 1432.5 kg/ha was recorded in plots pollinated only with A. mellifera inside insect cages. Open pollination with 10% jaggery solution spray increased the seed yield of dill seed crop by 57%, one-thousand seed test weight by 96% and the essential oil content by 27% over control plots. These results show that managed pollination is a much better way to enhance yields and quality of dill seed crop than other treatments including only honeybee-based pollination.