Control of cucumber damping-off caused by Pythium ultimum, with organic matter
2017
BETTIOL, W. | MIGHELI, Q. | GARIBALDI, A.
The effectiveness of several media soil-sand-pertile (1:1:1 v/v); soil-sand-pertile-manure (1:1:1:3); soil-sand-perlite-compost (1:1:1:3); soil-sand-perlite-peat (1:1:1:3); soil-sand-perlite-straw (1:1:1:3), and sand-perlite-peat-compost-mamure-wheat straw (2:2:1:3:3:1) as suppressers of the cucumber (Cucumis sativus) damping-off causal agent, Pythium ultimum, was evaluated. The media were infested with 12 g/l of Pythium inoculum (broken corn-sand medium), fifteen days before sowing ten cucumber seeds (mezzolungo Marketer) 1 cm deep in pots containing approximately 500 ml of medium. Plants were grown at a constant temperature of 25oC simbolo 177\\ f "Symbol" \\s 12 2 with 12 hours of illumination per day. The percentage of emerged seedlings, post- and pre-emerg ent damping-off and disease severity were determined at fifteen days after planting. This procedure was repeated on the same substrates, without reinoculation, ten days after harvesting this first trial. The manure medium was the most suppressive to the disease, with percent of emergence, percent of pre-and post-emergence damping-off and disease severity values of 84.5%, 12.0%, 0% and 1.35, respectively, for the first bioassay. The replanting experiment results were 98.5%, 0%, 0% and 1,0, respectively. However, plants grown in this medium in both bioassays were shorter than ones grown in the other media. Peat medium and the mixture sand-peat-manure-compost-wheat straw medium were more conducive to the disease than wheat straw medium, resulting in higher occurrence and severity of attack by Pythium.
显示更多 [+] 显示较少 [-]