Effect of Tryptophan and Ascorbic Acid on Yield and Some Chemical Constituents of Lupine (Lupines termis L.) Plants

A FIELD experiment was carried out during two seasons 2017/2018 and 2018/2019 to study the effects of spraying Tryptophan and Ascorbic acid on yield components and chemical composition of plants using two cultivars Giza-1 and Giza-2 of lupine plants. Foliar spray of Tryptophan at rate (Trp.: 25 and 50mg/L), Ascorbic acid (AA: 100 and 200mg/L) either alone, or their combination and control. The effect of the previous treatments on yield and its components namely {plant height (cm), pod length (cm), number of branches/plant, weight of 100 seeds, seed yield/plant (g) and seed yield/fed (ton)}wear investigated as well as chemical composition such as, total nitrogen, crude protein (CP), total soluble sugars (TSS), crude lipids (CL), total alkaloids (TAs) and total phenolic compounds (TPCs). Results indicated that foliar application Tryptophan and Ascorbic acid significantly improve yield and chemical composition. Trp. was more effective than A.A. in raising lupine yield, significantly increased yield of lupine plants, plant height (cm), pod length (cm), number of branches/plant, weight of 100 seeds, seed yield/plant(g) and seed yield/fed (ton). Total nitrogen, crude protein (CP), total soluble sugars (TSS), crude lipids (CL), total alkaloid (TAs) and total phenolic compounds (TPCs) in seeds lupine were significantly enhancement by mounting Trp. from 25to 50mg/L and/or A.A. concentrations up to 100 and 200mg/L. Generally, it is obvious that Giza-2 cultivar surpassed Giza-1 cultivar in the first and the second seasons, respectively in plant height (cm), Pod length (cm), number of branches/plant, weight of 100 seeds, seed yield per plant (g) and per fed (ton), crude lipids, total soluble sugars and total phenolic compounds and it is obvious that Giza-1 cultivar surpassed Giza-2 cultivar in both seasons in total nitrogen, crude protein and total alkaloid.