New Products against Apple Scab and Powdery Mildew Attack in Organic Apple Production

A study was undertaken on the effectiveness of some fungicides such as wettable sulphur copper hydroxide potassium bicarbonate and potassium bicarbonate mixed with potassium silicate against apple scab and apple powdery mildew attack in the environmental conditions of Cluj Napoca Romania. The following cultivars were analyzed Jonathan Gala Jonagold Jonica Golden Delicious Idared Granny Smith and Starkrimson in an experiment conducted over two growing seasons (2009 2010) in five treatment variants Potassium bicarbonate and a mixture between potassium bicarbonate and potassium silicate proved to be more effective in reducing the attack of apple scab and powdery mildew on leaves and fruit Results were obtained for two years with favourable conditions of apple scab and powdery mildew development when untreated variants exhibited an attack degree at a mean value of 49 77% for scab and 52 13% for powdery mildew Potassium bicarbonate and potassium bicarbonate mixed with potassium silicate assured the best results in the case of the Idared Jonathan Jonica cultivars regarding apple scab and Golden Delicious Starkrimson and Granny Smith regarding powdery mildew where the mean value attack degree was reduced by about three times The treatments with the products used in the experiments did not register symptoms of phytotoxicity on leaves or flowers Given that this product is not toxic to human health It becomes a perspective fungicide especially for organic fruit tree growing in order to control apple scab and powdery mildew attack