Interactive effect of phosphorus and boron on plant growth, nutrient accumulation and grain yield of wheat grown on calcareous soil

Abstract

Most of the arable soils in Pakistan are deficient in plant available phosphorus (P) and boron (B) primarily due to alkaline and calcareous nature along with low organic matter. A combined deficiency of these nutrients may intensify the plant growth suppression by reducing their efficient utilization. A pot experiment was conducted to investigate the interactive effect of P and B on growth, nutrient accumulation and grain yield of wheat grown on calcareous soil. Wheat crop was grown at three P levels (45, 90 and 135 kg P ha -1 ) in combination with five B levels (0, 0.5, 1.0, 1.5 and 2.0 kg B ha -1 ) following completely randomized design. The results revealed that yield and yield related attributes increased linearly with the addition of B at each P level. Nonetheless, the significant interactive effect of both nutrients was most pronounced in the treatment having 90 kg P ha -1 and 1.5 kg B ha -1 . Applied B rates resulted in relatively higher P concentration in grains and straw at P level of 90 kg ha -1 contrarily to 45 and 135 kg P ha -1 . The B concentration in grains and straw increased with corresponding addition of B at each P level but at variable rate, with the maximum response at higher P level. Grain and straw yield illustrated positive correlation with total P uptake (R 2 = 0.96 and 0.81) and total B uptake (R 2 = 0.95 and 0.70) respectively. Likewise, positive correlation (R 2 = 0.94) between total P uptake and total B uptake under combined application of P and B indicated their synergistic relationship. Overall, the treatment combination of 90 kg P ha -1 with 1.5 kg B ha -1 was found as the most suitable dose for better plant growth, nutrient accumulation and grain yield of wheat.