Nematoden im Ökologischen Gemüsebau - Ergebnisse einer Status-Quo-Analyse

Summary

During the last years damage caused by plant parasitic nematodes in organic field vegetable farming has been observed with increasing attention. A general inquiry was started on farms with nematode problems to collect information about infestation, crop rotation and control strategies. Soil samples from 207 vegetable fields were taken from 55 farms in Germany and the detected nematodes were analysed. Seventeen different genera of plant parasitic nematodes were found. Nematodes of the genus Pratylenchus were found on 90 % of Meloidogyne on 50 % of the analysed fields - these two are the most important genera that damage vegetables. More than half of the infested fields were of sandy soils. Yield reductions of 50 % could be observed on 40 % of the fields evaluated, with carrots being the crop most damaged by nematodes. Tendencies show that higher yield reduction was found on fields with sand and sandy loam and with low valuation index, low organic matter and low pH. Furthermore, dry, non-irrigated fields as well as fields with high weed pressure were especially damaged by nematodes.