Potassium bicarbonate in preventing and control of apple scab.

Abstract

Experimental results in the past years recommend using potassium bicarbonate like fungicide in preventing and control apple scab and other apple diseases. Field experimental was carried out in 2008 at a commercial orchard of SC Agroindustriala SA Cluj-Napoca. The trees were planted in 2003 at a distance of 3.5 x 0.9 m. The efficacy of potassium bicarbonate in comparison with other cupper and sulfphur based fungicides in preventing and control apple scab on seven apple cultivars (Golden Delicious, Starkrimson, Pinova, Idaread, Granny Smith, Gala si Jonica) was tested.Potassium bicarbonate in quantity of 5 kg per hectare proved to be equally effective in reducing attack of apple scab on leaves and fruit of the apple cultivars studied like wettable sulphure (4 kg/ha) or copper hydroxide (5 kg/ha). Results were obtained in a year with favorable conditions of scab development, when untreated variants control had an attack degree (AD%) ranged 19.6-55.6%. Potassium bicarbonate assures the best results at Idared and Pinova cultivars, where the attack degree was reduced by about five times. The treatments with potassium bicarbonate 0.5% not registered 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 to control apple scab.