Effectiveness of the biopesticide Endorse to control Cylindrocarpon root rot on ginseng seedlings, 2005

摘要

Stratified ginseng seeds were mixed in silica sand and stored at 38oF until germination. Germinated seeds were hand planted into 72-cell flats containing sterilized silica sand. Once seedlings emerged, they were carefully removed from the sand and observed for disease symptoms. Any seedlings showing root discoloration were discarded. Inoculum was prepared by growing C. destructans on potato dextrose agar for 8 weeks. The upper layer of the agar was removed, macerated in water, and diluted to a concentration of 2.9 x 107 spores/fl oz. The bare-rooted plants were then dipped into the spore solution for 10 sec. and planted in 24-cell packs containing a soilless medium (Baccto Professional Planting Mix, Michigan Peat Company, Houston, TX) on 27 Apr. Eight single-plant replications were placed into a completely randomized design. Two trials were run simultaneously. Fungicides were applied as a drench until runoff on 27 Apr and 11, 25 May. A plant health rating (1=healthy, 2=chlorosis, 3=minor wilting, 4=severe wilting, and 5=plant death) and death (%) wererecorded on 18, 25 May and 1 Jun.