Foliage applied boron along with boron-tolerant bacteria (Bacillus sp. MN54) ensures better nodulation, growth, grain yield and grains-B biofortification of chickpea

Abstract

Boron (B) deficiency is the leading constraints in chickpea production in calcareous soils; albeit the range between B deficiency and toxicity is very narrow. Boron-tolerant bacteria (BTB) can optimize plant functions under B-deficient conditions by improving its uptake and can also tolerate B toxicity. This two-year pot study was conducted to optimize the best level of B as foliar application along with BTB (Bacillus sp. MN54) inoculation to improve nodulation, yield and grain-B concentration of chickpea. Two sets of pots, one with BTB inoculation and other without BTB were prepared. Foliar treatments of B were applied to plants at concentrations of 0.000, 0.023, 0.046, 0.069, and 0.092 M while plants sprayed with distilled water were taken as control. Boron application improved root and growth-related traits, nodulation, yield-related traits and grains-B concentration compared with no B and water spray controls. Among levels tested, foliar application of 0.046 M B solution was better in improving root system, nodulation, yield-related traits; while higher B levels resulted more grains-B concentration. Seed inoculation with BTB further augmented chickpea productivity compared to non-inoculation controls. Foliar application of B (0.046 M) coupled with BTB enhanced number of grains per plant (40%), nodules population (60%) and grain yield (43%) compared with control. Lower levels of B (≤0.069 M) seemed good to improve yield-related traits while its higher levels improved grains-B concentration. In crux, foliar application of 0.046 M B solution along with seed inoculation with BTB (Bacillus sp. MN54) seemed a pragmatic option to improve nodulation, yield and grains-B concentration of chickpea.