Imbalance between boron and phosphorus supply influences boron deficiency symptoms in Brassica napus L.

BACKGROUND

The occurrence of boron (B) deficiency in Brassicaceae crops has increased in recent years. Inappropriate application of B with other nutrients often exacerbates symptoms of B deficiency. The aim of this study was to explore the interactive effects of B and phosphorus (P) on the B deficiency symptoms of rapeseed (Brassica napus L.). Two rapeseed cultivars ('W10' and 'ZS11') were treated with two B application rates (low and high B) and three P application rates (low, medium, and high P), and the growth parameters (root morphology, B absorption and distribution, and the P/B ratio) were examined in pot and hydroponic experiments.

RESULTS

Under low B conditions, plants showed severely reduced root and shoot growth but it was greatly improved when supplemented with medium P supply. Further analysis revealed that high P combined with low B decreased the B concentration of newly initiated leaves and seeds, and increased the P/B ratio in plants compared with the medium P and low B combination, resulting in the aggravation of B deficiency of rapeseed. In comparison with the B-inefficient cultivar 'W10', the B-efficient cultivar 'ZS11' had superior growth and seed yield under low B conditions. Furthermore, 'W10' and 'ZS11' displayed significant differences in the response of the interaction between B and P to plant P/B ratio and root morphological parameters, which may reflect distinct genotype characteristics.

CONCLUSION

The findings emphasize the importance of interactions between B and P in the growth and yield formation of rapeseed in B-deficient soils, as imbalanced B and P supply can exacerbate B deficiency symptoms in rapeseed. © 2025 Society of Chemical Industry.