For many years, Syngenta has been using bumblebees to pollinate our plants for seed production However, they noticed in the Helleborus seed production greenhouses that the bumblebees were slow compared to other crops and did not do a lot of pollination. This meant we had to add manual pollination to complete the pollination process.
"We invited an expert from the company Koppert which is specialized in biological pollination systems, to help figure out what we could do to get the bumblebees to pollinate. We found out that the bumblebees did not really like the low temperature of 8 °C in combination with the high humidity. Helleborus is namely the only crop that is produced in winter. It flowers in December and January with obviously the least daylight and the lowest temperatures," they say.
"So, after some recommendations, we raised the temperature in the greenhouse with a few degrees during the day, to 12°C. This also resulted in a lower greenhouse humidity, which bumblebees find more pleasant, we soon found out. We also fed the bumblebees with pollen to keep them sufficiently active when there was a shortage of pollen. Lastly, we hung up the housing-boxes higher in the greenhouse so that daylight touches the boxes earlier and longer. These adjustments made the bumblebees fly better and work to their full potential.
We also noticed that the pollination by bumblebees was a lot better and more effective than manual pollination because they visited a higher number of flowers per minute and had a better sense of timing on when to pollinate certain flowers. We went from 400 manual pollination hours down to 30 – 40 hours. Which is truly an incredible outcome."