Biologia kwitnienia i zapylania warzyw baldaszkowych. Część I: Koper ogrodowy (Anethum graveolens L.) [Biology of the bloom and pollination of the umbelliferous vegetables. Part I: Garden dill (Anethum graveolens L.)]

Abstract

The biology of blooming of garden dill and the influence of insect pollination on seed seetting was investigated. The experiment was carried out near Lublin, on the loessy soils within two different habitats in the season 1977-78. In order to determine the sugar weight of nectar isolated flowers were washed out, then the water enclosed in the nectar was vaporized and the remaining sugars underwent repeated dissolution and determined quantitatively with refractometer. The pollen yield was determined with the ether-weight method. The number of the secreting stomata on the epidermis of the nectary was on the average 950 per 1 mm². The sugar weight of 0.4 mg and pollen weight of 0.63 mg from 10 flowers informed of the attractiveness ofthe garden dill for the pollinating insects. The estimated honey yield of garden dill was 27.8 kg ha^-1 and pollen yield was 18.7 kg ha^-1. The isolation of the flowers from the pollinators brought about the decrease of the seed yield of 30% in 1977 and of 43% in 1978. The presence of the entomofauna on the flowers must be taken into consideration when forecasting the seed yield in the horticultural production of the garden dill.