Investigation on the effectiveness of compounds containing macro- and microelements on the reduction of Cytospora canker disease of stone fruit trees

According author's experiences and reached reports from different provinces of Iran Cytospora canker disease is one of the most important diseases in stone fruit trees which causes drying a lot of trees every year. One of the most basic controlling methods is fertilization trees with nutritional elements. Which combination or combinations contain nutritional element that are needed for trees and can prevent from attack or canker damage is subjected to this project investigated on it. The purpose of this project was defining the role of combinations contain macro- and microelements in decreasing or increasing Cytospora canker damage. In the first year of performance, 200 young trees (Elberta cultivar) were prepaired and 174 young trees cultivated in plastic vases. These young trees were maintained in natural condition and watered adequately and regularly. The experiment was done in randomized complete blocks design. The number of experimental treatments with control were 58 in 3 replication. Experimental treatments were contained: NH4 NO3, KNO3, CaSO4 + Ca H (PO4)2.2H2O, (NH4)2HPO4, K2SO4, K2SO4 + MgSO4, Ca(NO3)2, MgSO4, Mg(NO3)2, (NH4)2SO4, each one in 3 concentration 1, 10 and 100 g/l and MnSO4, CuSO4, H2B203, Na2B4O7.10H2O, ZnSO4, ZnO, FeSO4, FeO and Na2MoO4, each one in 3 concentration 1, 10 and 20 g/l and one treatment as the control. Young trees were inoculation with Leucocytospora leucostoma (Pers.) Höhn. (syn. Cytospora leucostoma Sacc.) Suspension in 5 * 10 5 cell/ml. Data were analyzed with SAS program and averages were compared with Duncan's multiple range test. Results showed that there were significant difference between experimental treatments (p=1%). Among the treatments lowest length necrosis symptom were belong to E6C3 (K2SO4 + MgSO4, 50 g/l), E6C2(K2SO4 + MgSO4, 10 g/l), E8C3 (MgSO4, 50 g/l), E16C3 (Zn O, 20 g/l), E8C2 (MgSO4, 10 g/l) with 1.93, 2.26, 2.30, 2.66 and 3.40 mm respectively. These treatments in compare with the other experimental treatments and control had partial preference. In anyone from young trees relative to treatments didn't observe gum and drying. In contrast, E1C3(NH4NO3, 50g/l), E10C3((NH4)2SO4, 50 g/l ), E4C1((NH4)2HPO4, 1g/l ), E1C2(NH4NO3, 10g/l ), E12C1( CuSO4, 1g/l ), E12C2(CuSO4, 10g/l ), E7C3( CaNO3, 50g/l ) and E11C1( MnSO4, 1g/l ) with 17.23, 16.33, 16.00, 15.90, 15.70, 15.63, 15.46 and 15.46 mm respectively had more canker length in compare with the other treatments.