This experiment was designed as a long term study, started in 2008 till 2014 with the idea of using sour orange as interstock on volkamer lemon rootstock (SO/VL) for budding four orange varieties, namely, Olinda valencia ,spring navel, Parent navel, and Fukumoto navel oranges. The purpose was to avoid some disadvantages of volkamer lemon on physical and chemical fruit quality with the hope of maintaining tree growth and its productivity with good properties acceptable for local and foreign market. The obtained results showed that, Olinda valencia, Spring navel, Parent navel and Fukumoto navel oranges on volkamer lemon rootstock showed the best tree size with higher growth parameters, while the interstock gave intermediate values with most vegetative growth parameters. On the other hand the lowest values of tested growth parameters were obtained on the scions budded on sour orange. In this respect, Olinda valencia orange gave largest tree size and strong vegetative growth parameters compared to other varieties. The highest values of chlorophyll a, b and total chlorophyll were recorded on Spring navel orange budded on volkamer lemon rootstock. Leaf NPK analysis showed that maximum leaf nitrogen content was recorded on Olinda valencia and Parent navel oranges. Phosphor was maximum for Spring navel orange. As for potassium, it reaches maximum values in leaves of Parent and Fukumoto navel oranges. In addition, yield in terms of weight (kg) of fruits/tree - kg/cm3of canopy volume and kg/cm2 of trunk cross section area (TCSA). were high on volkamer lemon followed by sour orange rootstock, and intermediate on interstock. The interstock tended produce yield near to that on sour orange rootstock with better fruit properties as found in part (B) of this study .