A Protocol Suggested for Management of Cantaloupe Downy Mildew

Abstract

The inhibitory effect of the fungicides Acrobat copper, Previcure-N and Unilax, the inducer resistance chemicals (IRCs) bion, chitosan, salicylic acid and zinc sulphate and the bioagents Bacillus polymyxa, B. subtilis and Pseudomonas fluorescens on sporangial germination of fungus like Pseudoperonospora cubensis, the causal of cantaloupe downy mildew was tested in vitro. The role of the tested fungicides, IRCs and bioagents on management of cantaloupe downy mildew was evaluated under greenhouse conditions. In addition, the alternation between the sprayed tested fungicide Unilax, IRC chitosan and bioagent P.fluorescens on management of the disease under field conditions was investigated. The inhibitory effect of the tested fungicides, IRCs and bioagents on sporangial germination of P. cubensis revealed that they caused significant reduction to the germinated sporangia. The tested fungicides were the most efficient ones followed by the bioagents then IRCs. Disease management showed the same trend of in vitro experiment when they sprayed on artificially inoculated cantaloupe plants with the sporangia of the causal fungus like under greenhouse conditions. Under field conditions, spraying cantaloupe plants with the tested fungicide Unilax still the most efficient trial for management the disease during 2012 and 2013 growing seasons compared with spraying any of IRC (chitosan) and the bioagent (P. fluorescens) alone . However, spraying the tested fungicide in alternation with the tested IRC and the bioagent ranked the second efficiency of disease management. Meanwhile, spraying the tested fungicide in alternation with any of the tested IRC and bioagent was of moderate efficiency.