Effects of NAA and nitrogen fertilizer on NPK uptake and nitrogen use efficiency of BARI gom-25 (Triticum aestivum L.)

Abstract

Effects of NAA (both as seed soaking and foliar spray) in combination with nitrogen fertilizer (0, 25, 50, 75 and 100% of recommended dose) on NPK uptake and nitrogen use efficiency (NUE) of BARI Gom-25 at flowering, grain filling, harvest and two sowing time (November 15 and 22) were evaluated. At flowering stage, significantly higher NPK uptake by shoot and root was obtained from seed soaking in 10 ppm NAA in combination with 75% N fertilizer (SOF₃) in both the sowing time with a few exceptions. But at grain filling stage, significantly higher NPK uptake by both shoot and root and N uptake by root was recorded from seed soaking in 10 ppm NAA in combination with 100% N fertilizer (SOF₄) followed by SOF₃ treatment. In comparison to full dose of N fertilizer, significantly higher NPK uptake by shoot, root and grain was also recorded from SOF₃ treatment in most of the cases. Findings indicated that NAA treatment at varying N-level had better stimulation on N and P uptake when sown on November 15 than November 22. However, the trend was reverse in case of K uptake. The NUE was significantly influenced by NAA at various N-levels. At flowering stage, significantly higher NUE of shoot and total plant was obtained from SOF₃ treatment in both sowing times. Whereas at grain filling stage, the same response was recorded from seed soaking in 10 ppm NAA in combination with 25% N fertilizer (SOF₁). Foliar application of 20 ppm NAA in combination with 25% N fertilizer (SSF₁) also resulted significantly higher NUE of root at both flowering and grain filling and those of shoot, grain and total plant with a few exceptions at harvest.