Effect of Transplant Age, Biofertilization, and Nitrogen Fertilizer Levels on Growth and Yield of Cabbage: Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Phiolosophy in Agricultural Sciences Horticulture / by Ehab Awad-Allah Ibrahim Ibrahim; Supervisors Mahmoud M.M. Zaghloul, Samir T.M. El-Afifi. Ibrahim, Ehab Awad-Allah Ibrahim.