Snap Bean (Phaseolus vulgaris) Response to Deficit Irrigation and Nitrogen Fertilizer and Relationships between Yield, Yield Component, and Protein Content

Abstract

Field experiments were conducted at Adami Tulu, Ethiopia, for two successive dry seasons to investigate how nitrogen levels and deficit irrigation affect the yield and its related components, and the protein content of snap beans. The treatments were deficit irrigation with three levels (50, 75, and 100% ETc) and application of nitrogen with four levels (0, 46, 92, and 138 kg·N·ha−1), which were set up as split-plot arrangement, with irrigation being as the main plot and nitrogen levels as subplot, replicated thrice. Results showed that the pod yield had a substantial impact ( p < 0.01 ) on the interaction between the two factors; i.e., interaction of 100% ETc and 92 kg nitrogen levels per hectare recorded the highest pod yield (22.69 t·ha−1), but treatment combinations of 50% ETc and no nitrogen application produced the lowest amount of overall pod yield (6.922 tons per hectare). However, the results showed that the application of 75% ETc in combination with 92 kg nitrogen per hectare recorded the highest protein concentration (17.718%) but statistically equivalent to 138 kg nitrogen per hectare combined with the same deficit irrigation level, while the lowest protein concentration (12.24%) was recorded at 50 ETc combined with no fertilizer. Hence, the use of 75% ETc along with 92 kg nitrogen levels per hectare could be optimal in balancing quality and pod output of green beans at Adami Tulu and surrounding areas.

Variability of Nutritional, Antioxidant, and Textural Traits of a Collection of Snap Beans of Different Colors

“…Regarding the two main nutritional traits, protein content and sugars content, the relative ranges were between 16.82% (SBP064) and 26.59% (SBP073) and between 4.27 • Brix (SBP036) and 6.40 • Brix (SBP098), respectively. The broad range of variability of protein content observed among the snap bean lines agreed with other studies [40][41][42]. Likewise, according to the literature, as well as in this study, significant differences were detected in the sugar content among the lines (Table S1).…”

How Nutritious Are French Beans (Phaseolus vulgaris L.) from the Citizen Science Experiment?

“…Delfini et al [ 23 ] reported a lower range (16.9–20.2 g/100 g) for protein content in seeds from 1512 accessions of Brazilian common bean germplasm compared to our data. The interaction between irrigation and nitrogen application during plant growth has a significant effect on protein content in French bean pods (12–18% DW) [ 24 ]. The highest caloric value among the samples was in the pods of KIS_10 and the lowest in the pods of KIS_3, but these differences were not significant.…”

“…Helium (He) was used as the reaction gas at a flow rate of 5 mL/min in He mode and 10 mL/min in HEHe mode. The isotopes monitored were 23 Na, 24 Mg, 31 P, 34 S, 39 K, 43 Ca, 55 Mn, 56 Fe, 59 Co, 63 Cu, 66 Zn, and 95 Mo. The majority of the elements were measured in the He mode, while P and S were measured in the HEHe mode.…”