Optimizing Boron Seed Coating Level and Boron-Tolerant Bacteria for Improving Yield and Biofortification of Chickpea

Abstract

Boron (B) is a vital nutrient equally important for plants and human beings. The native soil fertility of arid and semi-arid regions of Pakistan is very low where chickpea is grown on large scale. In such soils, B deficiency is the leading constraint not only for profitable chickpea production but also lead to low B-enriched chickpea grains. Boron seed coating and inoculation with B-tolerant bacteria (BTB) can be effective to improve crop response grown on such soils. Chickpea seeds were coated with different levels of boron (0.0 control; 1.0, 1.5, 2.0, 2.5, and 3.0 g B/kg). Coated and uncoated seeds were divided in two portions and half of these seeds were inoculated with BTB, i.e., Bacillus sp. MN54 while the other half of these seeds were not inoculated with BTB, i.e., Bacillus sp. MN54. Boron seed coating improved seedling growth, nodulation, seed yield, and grain B concentration. Crop response for such characteristics was further augmented with the inoculation of BTB. It was found that seed coating with 1.5 g B kg−1 along with BTB inoculation was the best combination to improve seedling growth, nodulation, and grain yield of chickpea. Higher concentration of B in chickpea seeds was recorded at higher levels of B seed coating (3.0 g B kg−1 soil). Boron seed coating improved grain yield by 9–25% compared with the control treatment. Boron seed coating at lower rates (1.5 g kg−1) along with seed inoculation with BTB Bacillus sp. MN54 seemed a viable option to improve nodulation, growth, yield, and grain B biofortification of chickpea.