Recently, several Bayer colleagues attended a workshop on Dropleg technology in Braunschweig, hosted by the Julius Kühn Institute (JKI). ‘Dropleg’ technology may reduce exposure to pesticides of insects visiting the flowers of certain crops as it sprays underneath the flowering canopy, as compared to conventional sprayers which apply the product above the canopy, onto the flowers of the crop. This is one of the things which were looked at under the ‘FitBee project’, and results were presented at the workshop. FitBee was a Germany-wide collaborative project which ran from 2010 to 2015, with the healthy, vital honey bee colony (‘FIT BEE’) as the central focus.
One module looked at how much crop protection products are brought into the honey bee colony and at ways to reduce exposure by agricultural measures. Bayer, together with the bee institute at University of Hohenheim, Syngenta, the machinery company Lechler and Amazone, supported research looking at whether applying foliar pesticides with the Dropleg application system helps reduce exposure to honey bee colonies. Other studies within this module checked whether the product being sprayed with the Dropleg equipment was still effective against the targeted crop pests and in how far drift losses could be reduced.
Dropleg technology reduces exposure of bees by spraying crops underneath the flower canopy.
Pesticide residue analysis studies show reduced colony exposure from nectar and pollen brought into the hive.
The workshop provided an opportunity for beekeeper Peter Trodtfeld, Bee Health Expert at Bayer’s Bee Care Center in Germany to present the results on bee exposure studies which were carried out over four years at the Bayer testing facilities. He presented the final results of the various semi-field residue studies done in oilseed rape, testing the neonicotinoid thiacloprid alongside another two active substances, azoxystrobin and T-fluvalinate. Tunnel tents were placed over the test plots to contain the bees. The test setup represented a worse-case scenario as the bees could only forage on the sprayed flowers. “The residue analysis in pollen and nectar collected from the beehives showed a clear reduction of the exposure of bee colonies to plant protection products using the Dropleg method compared to conventional application methods”, said Trodtfeld. Overall, the participants were impressed with the amount of work and the results of the residue tests. “The workshop allowed for open and constructive discussion, with ample opportunity to learn more about what others are doing around the new Dropleg technology”, he continued enthusiastically. The workshop presentations showed that most technical and mechanical challenges of the technology have been addressed and optimized, showing an acceptable efficacy in oilseed rape. “We have done the groundwork and shown the potential for this technology in reducing the amount of residue in nectar and pollen collected by bees”, concluded Trodtfeld, “beekeepers clearly appreciate these positive developments and now we need to show the agricultural community that the technology works and raise awareness. After all, this could be good news for farmers and also for bees.”