VPLIV UPORABE ZMANJŠANIH ODMERKOV FUNGICIDOV NA RAZVOJ PEPELASTE PLESNI (Podosphaera leucotricha  (Ell.&Ev.) in ŠKrlupa (Venturia inaequalis (Cooke) Winter)   pri jablani cv. "Jonagold"

  Mario LEŠNIK, Stane BERČIČ

 Fakulteta za kmetijstvo Maribor, SI-2000 Maribor, Slovenija

V nasadu jablan cv. "Jonagold" smo tri leta proučevali vpliv zmanjševanja odmerkov fungicidov na razvoj  jablanove  pepelaste plesni (Podosphaera leucotricha  (Ell. & Ev.) Salmon) in jablanovega škrlupa (Venturia inaequalis (Cooke) Winter).  Fungicide smo nanašali s prototipnim pršilnikom pri porabi 260 l škropilne brozge na ha. Primerjali smo učinkovitost delovanja fungicidov pri  100%, 80%, 65% in 50% odmerku. Stopnja okuženosti poganjkov s pepelasto plesnijo se je zaradi zmanjševanja odmerkov fungicidov v vseh treh letih izvajanja poskusov vedno značilno povečala. Stopnja  okužb listov in plodov jablane od škrlupa  se je zaradi zmanjševanja odmerkov fungicidov povečala samo v enem od treh let. 

ABSTRACT

  The effect of  fungicide dosage reduction on development of powdery mildew  (Podosphaera leucotricha  (Ell.&Ev.)   and  scab  (Venturia inaequalis (Cooke) Winter) on apples cv. 'Jonagold'

The  development  of powdery mildew  (Podosphaera leucotricha  (Ell. & Ev.)   and  scab  (Venturia inaequalis (Cooke) Winter) on apples cv. 'Jonagold' treated with reduced dosages of fungicides was investigated in a three-year study. Fungicides at 100%, 85%, 65% and 50% dosages were applied with special prototype sprayer at 260 l spraying volume ha^-1. Due to the reduction of fungicide dosages, the rate  of mildew infection on apple shoots significantly increased in all three  trial years. The rate of leaf and fruit infection by scab was significantly influenced by reduction of fungicide dosage only in one of the three years of experimental period.