Efficiency of more recent fungicides in control of apple scab and powdery mildew

Apple scab (V. inaequalis) and powdery mildew (P. leucotricha) are most economicaly important diseases of apple. Chemical measures are of the highest importance in controlling these diseases. There is great number of fungicides on the market. Fungicide choice and time of application depend upon mechanism of their action. Experiments on controlling apple scab and powdery mildew are carried out in 1998/99 and 2002. in different locations in Vojvodina. According to the obtained results the highest efficacy in the control of apple scab and powdery mildew have performed pesticides from strobilurin group (Stroby-kresoxim-methyl and Zato 50 WG-trifloxystrobin)as well as fungicides belonging to the new group of fungicides (Clarinet). In the disease control of the apple high efficacy have also performed DMI fungicides such as Score 250-EC (in control of apple scab). Topas-lOOE and Webeton (in control of powder) mildew). Lower efficacy have performed fungicides with preventive activity such as combination of Venturin S-50+Cosan. Unpublished data from previous studies (1995-1997) of the fungicide Chorus (cyprodinil) biological efficacy also suggested that this new generation fungicide from anylopyrimidin group showed better efficacy than fungicides belonging to former DMI fungicides, as well as contact ones.