THE PRESENT study was conducted under screen-house in the ……. nursery of Horticulture Res. Inst., Giza, Egypt on Sour orange (Citrus aurantium L.) and Volkamer lemon (Citrus volkameriana) rootstock seedlings during the growing seasons of 2011 and 2012. The study aimed to the assess the influence of using phosphorus, active dry yeast, algae(diatoms) and their combinations on growth and leaf mineral contents " N, P and K" of the studied rootstocks. The obtained results showed an enhancement effect on both rootstocks performance. Moreover, seedlings treated with either active dry yeast, algae or phosphorus and remarkably their combinations showed significant augmentations of growth parameters i.e., stem length, stem thickness, leaf area, dry weight of leaves and roots. Leaves nitrogen, phosphorus and potassium content increased significantly with such applications.
Therefore, it is recommended to use the combination between active dry yeast, algae and phosphorus to improve seedlings vegetative characteristics and shorten the time seedling needs to attain grafting size.