Measuring of the nectar yield of red clover heads

Authors

• Juhani Paatela Department of Plant Husbandry, University of Helsinki
• Hannes Heinrichs Department of Plant Husbandry, University of Helsinki

DOI: https://doi.org/10.23986/afsci.71510

Abstract

The paper gives an account of the method to measure the nectar yield of red clover heads. The method was developed at the University Farm at Viik in 1954, and based on two centrifugation methods employed earlier. The main attention was paid to the taking of the sample and its fast handling, because the heterogeneous nature of the material demands even in the case of one sample the examination of a considerably large number of heads. The secretion of nectar and sugar was more abundant in the large heads than in the small-sized ones so that for the obtaining of realiable data with a moderate number of heads the sample should be composed of heads of as near the same size (medium size) as possible. The shortening of the corollas by cutting before centrifugation proved unnecessary at least where sufficiently large glass tubes were employed. By changing the method of fastening the inflorescences and the form of the glass tube, and by inserting a metal gauze at the bottom of the capillary tube the clean nectar was easily directed into the capillary tube (Figs. 1 and 2).