Guideline for the efficacy evaluation of fungicides. Powdery mildew on cucurbits and other vegetables (revised and extended in 1989) [Erysiphe cichoracearum, Erysiphe cruciferarum, Erysiphe pisi, Sphaerotheca fuliginea]

brassica conception cucurbitaceae design erysiphe erysiphe cichoracearum essai evaluation fongicide fungicidas fungicides methode methods mildews mildiou oidium pathogenic fungi pisum sativum pruebas sphaerotheca trials