Effects of avoiding chemical synthetic pesticides with simultaneous nitrogen optimization on aphid abundance, aphid-antagonist relationships and antagonist diversity in wheat.

Autoren: Gitzel, J., Kampen, H., Hoffmann, L. M., Sellmann, J., Schwarz, J., Kühne, S., Ulrichs, C., & Werner, D.

NOcsPS   |   2015
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Sustainable management practices are needed to reduce adverse impacts of agriculture on biodiversity and ecosystem services. The aim of this study was to examine the effects of avoiding chemical synthetic pesticides with simultaneous nitrogen optimization on predator-prey dynamics of aphids (Aphidoidea) and their antagonists as well as antagonist diversity in wheat cropping systems of different management intensities (organic, conventional, and hybrid (no chemical synthetic pesticides with optimized use of nitrogen fertiliz­ers)) in Brandenburg, Germany. Each cropping system was established with four replicated plots of 50m² each. To assess the impact of management practices, sweep netting of aphids and visual counting of aphids and their antagonists, convert­ed into predator units, were conducted over the course of two years (2022 and 2023). Under the organic treatment, aphids and their antagonists exhibited higher abundances than in the other two cropping systems. The new hybrid crop­ping system was intermediate between organic and conven­tional systems, exhibiting higher populations of aphids and their natural predators compared to the conventional system. The application of chemical synthetic pesticides negatively impacted both aphid and predator populations directly and indirectly. Aphids were reduced by insecticides while preda­tors suffered from a lack of food resources or were also af­fected by insecticides as non-target organisms. Even though aphid abundance benefited from the reduction of chemical synthetic insecticides, a favorable development of aphid antagonists was observed in 2023. Notably, the avoidance of pesticides and the nitrogen optimization contributed to the increase of the number of individuals of aphid antagonists. Achieving a balance without the use of pesticides mitigates environmental damage and reduces the risk of pests devel­oping resistance.

Publikationsdatum: 2015
NOcsPS

Verlag: Landbauforschung - Journal of Sustainable and Organic Agriculture

Publikationstyp: Journal-Artikel