Competitiveness of Thirty-Eight Ecotype Species in Sown Perennial Flower Strip Within Apple Orchards in Belgium

Flower strips in orchards using native plants and local adapted ecotype has shown to be a promising approach to boost natural enemies of fruit pests and pollinators, providing shelter, nectar, alternative prey and pollen. Flower strips within the grass alleys, between fruit tree rows, allow to enhance natural enemies without spend additional area for fruit production. However, the key issue in habitat manipulation such flower strips so set within between tractor wheels in the orchard alley ways, concern adaptation to orchard design and practices. The aim of the study is to assess, during three growing seasons, the development of thirty eight selected ecotype species, including dicotyledons and grasses species, in sown perennial flower strip planted in intensive apple orchards in temperate European climatic area. The study shows that species with the highest overall mean recovery are Cynosorus cristatus L. (12.61%), Geranium pyrenaicum Burm.f. (11.06%), Leucanthenum vulgare Lam. (9.72%), Lotus corniculatus L. (6.15%) and Trifolium pretense L. (5.32%). Results indicate an exceptional installation of the flower mixture, with a covering dominance of sown dicotyledons without excessive concurrency of grasses. The nine functional agro-biodiversity (FAB) species, particularly interesting for biocontrol in orchards, have been able to develop themselves without being dominated, offering a great functional diversity. The average recovery of FAB species increased throughout the study period to reach 44.4% in autumn 2017.