The Effect of mandipropamid (SC 250), propamocarb hydrochloride+fluopicolide (SC 687.5), and mefenoxam+copper oxychloride (WP 42.5) on the Control of Downy Mildew of Cucumber (Pseudopronospora cubensis Berkeley & Curtis) in Glasshouse

Downy mildew of cucurbitaceae, Pseudoperonospora cubensis is one of the important diseases in cucumber growing areas, especially in greenhouses. There are certain recommended fungicides for the control of this disease, but, because of inefficacy in proper management, and chemical hazards, introduction of new fungicides based on required standards is highly essential. In this study, three new fungicides, mandipropamid (Revus® SC 250) at the rate of 1 and 1.5:1000, propamocarb hydrochloride繛ꢦ✨闗 (Infinito® SC 687.5) at 1.5 and 2: 1000 and mefenoxam copper oxychloride (Ridomil Gold® Plus WP 42.5) at 4 and 5:1000 were tested in comparison with famoxadone猩髅ꧢ (Equation® Pro WG 52.5) at 0.4:1000 with a control plot in a RCBD with 3 replicates at two different greenhouses at Falvarjan and Mobareke in Isfahan. The lowest disease incidence was observed in Infinito treatment at the rate of 2:1000; the Revus 250 SC at 1:1000 and Infinito SC 687.5 at 1.5:1000 with 8.12, 20.21 and 37.29 disease severity percentage were the most effective respectively. This indicating that the Infinito fungicide at the rate of 2:1000, with two times spraying in a week interval after the appearance of the first symptoms had showed the lowest disease severity. Also, the highest spore production on the lower infected leaves was observed in the control with 425 spores per every infected lesion. Whereas the lowest production was observed in Ridomil WP 42.5 at 5:1000 treatment with 33 spores per infected lesion.