A field experiment was carried out during seasons 2017/2018 and 2018/2019 seasons 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 50 mg /L) Ascorbic acid (A A: 100 and 200 mg /L)either alone, or their combination and control. The effect of the previous treatments on some vegetative growth criteria namely{ plant height (cm), pod length (cm), number of branches/ plant, weight of 100 seeds, and 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 and 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 50 mg /L and/or A.A. concentrations up to 100 and 200 mg/L.