Varietal response of faba bean to foliar boron supplementation: Implications for yield and seed quality improvement

Abstract

Faba bean (Vicia faba L.) is an important legume crop valued for its nutritional quality and ecological role in sustainable agriculture. Its productivity and seed composition can be influenced by micronutrient management, particularly boron (B), which plays a key role in reproductive development. The experiment comprised two faba bean varieties (black-seeded and brown-seeded) and five foliar B levels (0, 10, 20, 40, and 60 mg L^-1 applied at the pre-flowering and pod formation stages) in a randomized complete block design with three replications. The brown-seeded variety produced higher seed yield (2.32±0.04 t ha⁻¹) than the black-seeded variety (1.86±0.05 t ha^-1), while among B treatments, foliar application at 60 mg L-1 produced the maximum seed yield (2.32±0.07 t ha⁻¹) and the control gave the lowest one (1.85±0.10 t ha⁻¹). Although vegetative growth parameters were not significantly affected by B, reproductive and yield traits were notably improved. The combination of brown-seeded faba bean with 60 mg L^-1 B produced the highest number of branches plant^-1 (3.80±0.25), pods plant⁻¹ (38.60±1.42), seeds pod⁻¹ (3.53±0.05), 1000-seed weight (228.17±3.48 g), seed yield (2.48±0.04 t ha⁻¹), stover yield (2.55±0.04 t ha⁻¹), and biological yield (5.03±0.08 t ha⁻¹). The highest seed protein content (22±0.26%) was recorded in the brown-seeded variety without B, whereas the black-seeded variety treated with 10 mg L⁻¹ B showed the highest seed fat content (2.40±0.14%). These results indicate that 60 mg L⁻¹ foliar boron application to brown-seeded faba bean effectively enhances yield traits and yield, while seed quality traits vary by genotype and boron level.