*Horticultural Department, Ministry of Agriculture, Giza, Egypt.
Faculty of Agriculture, Cairo University, Egypt.
1. The influence of different rootstocks of the development of chlorosis on young Le Conte pear trees was investigated in the nursery.
2. Chlorosis resulted in a remarkable reduction in the/growth and development of the whole plant as indicated by stunted growth and reduced leaf production.
3. The chlorotic leaves were characterized by their decreased fresh and dry weight, leaf area, moisture and manganese content and by their high content of ash and iron.
4. Leaves of plants sprayed three times during the growth season with the solution containing 1% Mn SO4+0.5% Fe So4+10.1% dreft soap were very close to those of normal green plants in all respect.
5. The severity of chlorosis developed on Le Conte pear trees budded on the three stocks as well as the percentage of chlorotic plants was shown to, be determined by the rootstock used. Le Conte/P. calleryana plants has the highest percentage of chlorotic plants followed by those on P. communis and lastly those on quince.
