Flower reservoirs or flower boxes? Seeking the best low input strategy to promote biodiversity and pest control in modern stone fruit orchards

Summary

‘Flower reservoirs’ or ‘flower boxes’? What would be the best low input strategy to promote biodiversity and efficient pest control in modern stone fruit orchards? Flower strips are a known management strategy used in orchards and vegetable production which provide habitat for beneficial insects increasing biocontrol of pests and pollination of crop plants. Flowers strips between tree-rows however, are not widely implemented in fruit production because of logistical challenges such as additional machinery, and high efforts needed for establishing and maintenance of flowers strips. Table cherry in particular could benefit from flowering habitats within the orchards. The majority of table cherry in Switzerland are equipped with a rain-protection roof and lateral insect nets. The nets hinder pests like fruit flies from entering and at the same time the natural enemies of most pests. Particularly the build-up of colonies of aphids is facilitated by the insect nets and the lack of nectar, pollen source and habitat for reproduction. Consequently, natural predation is low and pre-flower and post flower insecticide applications are the standard in organic and integrated production. Farmers need therefore support in developing insecticide-reducing and practically feasible management strategies. In this project, we exploit our large experience in Agroecology, to promote biodiversity and natural pest control in modern orchards by testing two low input strategies. The overall goal of this research project is to test the use of either 1) perennial ‘flower reservoirs’ installed in areas adjacent to the tree-rows where tractors etc. do not transit or 2) pre-planted ‘flower boxes’ distributed within the orchard in places where they do not disturb the management. We are carrying out field trials on commercial organic cherry orchards with flower reservoirs or flower boxes. We expect to increase pollinator visitation and biocontrol of aphids in orchards where flower reservoirs have been implemented. In this talk, we will introduce you to the designs, and to our challenges and findings so far. We expect that by the end of the project we will be able to show that these two strategies can provide similar or even more benefits than those provided by flower strips between tree-rows, while reducing the logistical challenges and maintenance efforts needed from farmers, and therefore, increasing its acceptance and implementation.