ABSTRACT
The aim of this experiment is to study the performance of Valencia orange Cv., budded (T-budding) on three types of citrus rootstocks i.e., Volkamer lemon (C. volkmeriana), Sour orange (C. aurantium) and Balady lime (C. aurantifolia). The results showed that, Valencia orange transplants budded on Volkamer lemon rootstocks was statistically the superior. However, the greatest values of success percentage, both scion length and diameter, number of leaves per transplant, largest area of leaves and heaviest weights of fresh and dry shoot system were induced in both seasons. The richest leaves in their mineral contents either macro-elements (N, P, K, Ca and Mg) or micro-nutrients (Fe, Zn and Mn) as well as photosynthetic pigments and indoles were statistically in closed relationship with those Valencia orange Cv. budded on Volkamer lemon rootstocks.
Anatomical examinations of union zone of all investigated treatments proved the success of union process between citrus scions (Valencia orange) from one hand and any of the 3 rootstocks. However, grade of success was relatively varied as the perfect union depending upon the anatomical measurements base was concerned. Hence, anatomical examinations revealed that, budding of Valencia orange scion on Volkamer lemon followed by sour orange rootstocks showed to great extent the perfect union between two graft elements (scion & rootstock). Herein, the widest diameter of the whole section, secondary cortex in either union zone (newly developed tissues between two elements) or tissues of both scion and rootstock themselves, as well as the decrease of vacuoles and necrotic tissues all were clearly observed. The reverse was true with budded transplants on other rootstock (Balady lime rootstock) whereas wider vacuoles and thicker necrotic tissues associated with thinner layers of other union zone tissues were detected. |
