Growth, Yield and Water Use Efficiency of Fodder Beet Responses to the NPK Fertilizer and Withholding Irrigation

Two field experiments were conducted in the experimental farm of the National Research Center, Shalakan, Kalubia Governorate, during the to successful seasons to investigate the effect of fertilization and drought on growth and yield of fodder beet plants. The treatments of Drought were: 1- Without, irrigated regularly.2- withholding of 2ndirrigation.3- withholding of 4th irrigation a. Fertilization treatments were: 1- Without mineral fertilization, 2- P2O5+K2O, 3- N + P2O5, 4- N+P2O5+K2O. A negative relationship was detected between withholding irrigation and growth characters of fodder beet plants. The depressive effect was significant for number of leaves, fresh weight of root and total fresh weight and dry weight of root, top and whole plant, while the differences not great enough to reach the level of significant for plant height, length and diameter of roots and fresh weight of top. The lowest fresh roots or tops yields were obtained when plants subjected to drought by withholding the 2nd irrigation followed by that when the 4thirrigation withholding compare to the plants irrigated regularly. While that lowest tops, roots and total dry yields were obtained when plants subjected to drought by with holding the 4th the irrigation followed by that when the 2ndirrigation with holding compare to the plants irrigated regularly. Furthermore, the depression in yield of roots exceeded those in tops or biological yields. Plant height, number of leaves, root diameter and length and area of leaves increased in ascending order: PK NK NPK application. Application of NP fertilizers increased the root, top and whole fresh weight/ plant and these increases were more than that obtained by KP application. Moreover, application of NPK pronouncedly increased the root, and top as well as whole plant fresh weight to reached about 2-3 fold of that of control treatment. This was fairly true for dry weight of whole plant or root and top dry weight. Positive responses of fresh as well as dry weight of tops, roots and biological yield were detected with KP, NPand NPK fertilizers. Addition of combined fertilizer NPK the superior compared to KP or NP fertilizers, meanwhile, application of NP more affective in increasing fresh or dry yields of fodder beet plants than use of KP fertilizer. Data of WUE and interaction between the both treatments were included