Effect of Peach Cultivars, Rootstocks and Phytophthora on Iron Chlorosis

The cultivar and rootstock effect on iron chlorosis were studied. The results revealed significant differences among peach cultivars and rootstocks in mineral content. Seasonal changes were also found in the macroand micronutrient content of leaves of peach cultivars and rootstocks. The rootstock St. Julien 655/2 was found to be efficient in K, P, Zn, Fe, Cu absorption and better than seedling in iron uptake. Peach seedling with all cultivars had the lowest level of iron content. The rootstock GF677 was found to be a very efficient rootstocks for calcareous and dry soil. The leaf iron content of the cultivars grafted on it, was high. The lowest iron content was observed in the leaves of the cultivars Loadel and May Crest. The cultivar Sun Crest grafted on seedling rootstock died. These cultivars should not be planted in calcareous soils. Rootstocks affected significant the yield and mean weight fruit. The rootstocks J1 and GF677 gave the highest yield and the rootstocks ID3 the lowest. No significant differences were found in yield between DSS, GF677 and AN1/6 rootstocks. Also, the rootstocks DSS and ID3 did not differ statistically. The mean weight fruit did not differ statistically among DSS, AN1/6, J1 and GF677 rootstocks. The rootstock ID3 gave the lowest mean weight fruit. The fruit quality was similar for all rootstocks tested. The mortality of peach trees was affected from rootstocks and varieties. The present study also showed that trees of the peach rootstock Myrandier 617 inoculated with the isolate P. cactorum 1906 had significant lower chlorophyll index than control. In contrast, the isolates P. megasperma and P. cactorum 1168 increased significantly the chlorophyll index in the rootstock J1.