Pot experiments with pasture soils to detect soilborne pathogens of white clover and lucerne, and effects of field application of fungicides

摘要: Abstract Seedlings grown under glasshouse conditions in pots of pasture soil from sites the North Island New Zealand were used to detect pathogenic soilborne fungi and nematodes. White clover (Trifolium repens L.) seedlings sampled pastures low productivity on three Auckland farms showed damping-off caused by Thanatephorus cucumeris (Frank) Donk, root rot Chalara elegans Nag Raj & Kendrick. These pathogens also detected samples trial plots sited Waikato, Taupo, Bay Plenty regions. Lucerne (Medicago sativa these affected Pythium irregulare Buis. Less occurred treated with fungicides metalaxyl triadimefon than untreated plots. Seed treatment or pyroxyfur reduced damping-off. Cultivars lucerne diploid red (T. pratense susceptible more isolates P. irregula...