Efficiency of new fungicides in the control of cucumber downy mildew causal agent

Abstract

Pseudoperonospora cubensis (Berk and Curt) Rost. causing downy mildew in cucumber represents the major economic pathogen of cucumber. Severe infestations may imperil the entire cucumber production. The efficiency of some novel fungicides (dimethomoiph, azoxystrobin) in the control of P. cubensis was tested throughout 1997-1998. Metalaxyl was used as a standard. The experiment was conducted at the PIK 'Zemun' sites using standard methods for testing the biological efficacy of fungicides (OEPP, 1990). The trials were carried out on salad and pickling cu­cumbers (cv. Regal). The sprayer Falson was used and 500 l/ha of fungicides were applied. During 1997 five treatments were employed. Four treatments at 7-day intervals were employed during 1998. Based on the results obtained the conclusion which tends to emerge is the high efficiency of the fungicides dimethomorph (90.3-97.1%), azoxystrobin (95.6-97.0%) followed by metalaxyl (40.2-84.0%) in the control of P. cubensis. .

Psudoperonospora cubensis (Berk i Curt) Rost. prouzrokovao plamenjače krastavca pripada grupi ekonomski najznačajnijih patogena krastavca. U slučajevima jače pojave ovog oboljenja celokupna proizvodnja krastavca može biti ugrožena. Tokom 1997-1998. godine ispitivana je efikasnost novijih fungicida (dimetomorf, azoksislrobin) u suzbijanju P. cubensis. Kao standard korišćenje metalaksil. Ogled je postavljen na proizvodnim površinama PIK 'Zemun ', po standardnoj metodi za ispitivanje biološke efikasnosti fungicida (OEPP, 1990). Eksperimenti su izvedeni na salatnom krastavcu (sorte Sunčani potok) i kornišonu (sorte Regal). Primena fungicida je izvedena pomoću prskalice tipa Falcon, sa lepezastim mlazom uz utrošak 500 l/ha tečnosti. Tokom 1997. godine izvedeno je pet, a u 1998. godini četiri tretiranja u intervalu 7-10 dana. Dobijeni rezultati ukazuju da su ispitivani fungicidi ispoljili visoku efikasnost u suzbijanju P. cubensis, dimetomorf (90,3-97,1%), azoksistrobin (95,6-97,0%) a metalaksil slabiju (40,2-84,0%).