GROWTH AND YIELD RESPONSES OF TRITICUM AESTIVUM L. VAR. BARI GOM-26 FOLLOWING APPLICATION OF NAPHTHALENE ACETIC ACID AT VARYING NITROGEN LEVELS

A field experiment was conducted to study the effects of NAA (25 and 50 ppm) in combinations with four levels of nitrogen fertilizer (0, 50, 75 and 100% of the recommended doses) on the growth and yield of wheat (Triticum aestivum L. var. BARI Gom-26). Plant height increased maximum due to 50 ppm NAA in combination with 50% N-fertilizer, whereas the minimum was due to 25 ppm NAA alone. Maximum number of tillers and leaves per plant were obtained due to 25 ppm NAA in combination with 50% N-fertilizer. The highest total dry matter (TDM) per plant was produced by 25 ppm NAA in combination with 75% N-fertilizer at all the stages of the growth except at 15 and 30 days after spray (DAS) and significant variation was observed at 45, 60 DAS and at harvest. Except length of spike and non-effective tillers per plant, the number of effective tillers per plant, 100-seed weight and yield (g/plant and t/ha) increased significantly due to 25 ppm NAA in combination with 75% N-fertilizer. Non-effective tillers per plant tended to increase with the application of N-fertilizer alone and showed decreasing tendency with other combinations. Harvest index varied non-significantly and highest harvest index was recorded due to 25 ppm NAA in combination with 75% N-fertilizer.