Response faba bean cv. “Giza 3” to folair application of GA3 and tryptophan

A field experiment was conducted in Sof Al-Jin Farm in Bani Walid, Libya, during the agricultural winter season 2022/2023 to study the effect of spray of GA³ at 50, 100, 150 mg/l and tryptophan at 100, 200, 300 mg/l and control treatment (tap water) on vegetative growth, yield and yield components and chemical composition of faba bean cv. “Giza 3”. The experiment was applied according to Randomized Complete Block Design (RCBD) with three replicates for each treatment. The results showed that the increasing of the concentration of tryptophan up to 300 mg/l led to increase some vegetative growth (plant height, number of branches/ plant, shoot length, shoot dry weight, total chlorophyll, leaf area), yield and yield components (pod weight, pod length, number of pods/plant, number of seeds/pod, 100 seeds weigh seed yield, biological yield) and chemical composition (nitrogen, phosphorus, potassium, protein and tital carbohydrates percentages), followed by folair application of GA₃ at 150 mg/l, as compared to control treatment (spray tap water). In addition the data revealed that, foliar spraying of either tryptophan or GA₃ led to significant increases in faba bean vegetative growth, yield and yield components as well as significant improvement of the nutritional status of faba bean plants and seeds nutrient, carbohydrates and protein content. The results showed that foliar application of tryptophan was more effective than GA₃ in concern of growth, yield and yield components plant and seeds chemical constituents and nutritional status especially at the high concentration (300 mg/l tryptophan and 150 tryptophan GA₃).