News
New publication: Borax promotes fertility of Brassica napus better than other boron species at suboptimal supply
Background
Continuous and sufficient boron (B) supply is essential for achieving maximum yield in Brassica napus. Increasing incidences of environmental water limitation are linked to reduced plant B availability and increased B deficiencies. Developing an optimized fertilization strategy that considers the release speed of different B fertilizers is crucial to prevent B-deficiency during flowering.
Aims
Evaluation of different B species’ ability to sustain growth and fertility of B. napus during flowering under single and combined B-deficiency and water-limitation stresses.
Methods
The effects of highly soluble/fast-release (boric acid, borax) and slow-release (colemanite, ulexite, zinc borate) B species on plant phenotype and B status was investigated before and during flowering on B-sufficient and severe and moderate B-deficient conditions with varying water availabilities.
Results
Under B-deficiency, plant performance when supplied with the different B species decreased in the following order: borax > boric acid > ulexite > colemanite or zinc borate. Under well-watered and severe and moderate B-deficient conditions, borax application led to higher shoot dry weight, shoot B content, and more asymptomatic flowers than the other B species, on water-limited conditions only under moderate B-deficiency. Independent of B species, root length correlated positively with shoot B content, and shoot head B concentration before flowering correlated positively with the number of asymptomatic flowers.
Conclusions
In B-deficient conditions, floral performance of B. napus is driven by the B species supplied and the soil water status. Fast-release fertilizers, and particularly borax performed best in both well-watered and water-limited treatments, likely due to more continuous availability.