Over the summer of 2017, we are working in partnership with Hozelock to determine whether foliar feeding can increase floral abundance, nectar and pollen quantity and quality, and find out whether this relates to increased bumblebee visitation.
We are growing 48 tubs of ‘Ladybird’ nasturtiums which are receiving a weekly foliar feed of either Agralan comfrey liquid, Chase SM4 seaweed feed, mains tap water or no foliar feed. The feeds are being applied using the Hozelock Pure sprayer.
We have been busy carrying out regular bumblebee observations and have found the most frequent visitor so far to be the Buff-tailed Bumblebee, although during the hot weather last week, there was very little bumblebee activity. Hopefully, the cooler forthcoming weather will result in increased visits and we will be able to identify whether the bees are demonstrating any preferences.
Nectar and pollen from the different treatments is also being tested to identify any differences in quantity and quality. Nectar is extracted from the flowers by placing a fine glass tube into the spur, which draws up the liquid by capillary action. The liquid is then dropped onto a refractometer which measures the percentage sugar by the way that light passes through it. This week, we will be using a microscope and haemocytometer slide to count the number of pollen grains present in the nasturtium flowers. It will be interesting to see if there are any differences between the various treatments.