Water use efficiency (WUE) and nutrient concentration of selected fodder radish (Raphanus sativus L.) genotypes for sustainable diets

Changing climates threaten crop growth and fodder yields in dryland farming. This study assessed two radish genotypes (LINE 2, ENDURANCE) under three water regimes (W1 = well-watered, W2 = moderate stress, W3 = severe stress) and two leaf harvesting options over two seasons (2021/22 and 2022/23). Key findings revealed that water regime significantly (P < 0.05) affected WUE, with W2 yielding (4.71 kg ha-1 mm-1) higher values. The combination of W3 and LINE 2 biomass were reduced by ≈ 60.09% in 2021/22 and ≈ 71.06% in 2022/23, whereas ENDURANCE declined by ≈ 63.9% and ≈ 53.33%. Tuber yield was highest under W1 and W2, with ENDURANCE yielding 59 t ha-1 (W1) and 48 t ha-1 (W2). Generally, W2 reduced micronutrient concentration (iron, zinc, β-carotene and vitamin C). For example, W2 improved vitamin E and key findings showed that human dietary for women and children can be met. The W3 exceeded vitamin E, iron, and zinc recommendations for all ages. The genotypes showed similar biomass and CP yield under W2 and W1, indicating moderate water stress can sustain yields. These findings highlight the importance of strategic water management for food and fodder security, while meeting nutritional needs in water-scarce regions.