Effect of Spray with Edetate Magnesium Sulfate and Salicylic Acid on Shoot Fire Blight in Pear cv. Louise Bonne

Fire blight disease caused by Erwinia amylovora is the most important and serious biotic stress on pear worldwide and in Iran, therefore its control in infected areas is important economically. Science the common methods of disease control are inefficient in control of fire blight, other ways should be investigated to overcome the disease. The present study was carried out to find an efficient way of control based on supporting plant tissues and reducing growth of shoots by application of edentate managenesium sulfate and salicylic acid. In this study which was carried out in Qazvin during 2012 and 2013, the effects of different concentrations of manageseium sulfate and salicylic acid an disease incidence and bacterial population were investigated on pear cv. Louis Bonne in an infected orchard and in laboratory. The results showed that effects of different concentrations of mineral compound and their combinations on disease development and shoot growth were significantly different compared to the check treatments in both years. Increasing the concentration of mangenesium sulfate from 0.5 to 0.7 g/1000 had a positive effect on disease reduction but increase of the concentration of Salicylic acid from 0.1 to 0.5 g/1000 had a negative effect on disease reduction. The results also indicated that if the effects of nutrients such as managenesium sulfate are supported by the effects of Salicylic acid in shoot growth inhibition, a better disease control will be achieved.