Timing of Nitrogen Fertilization of Rice. II. Culm Elongation as a Guide to Optimum Timing of Applications near Midseason
1968
Hall, V. L. | Sims, J. L. | Johnston, T. H.
Field studies were conducted with ‘Vegold,’ ‘Nato,’ and ‘Bluebonnet 50’ rice (Oryza saliva L.) in 1963, 1964, and 1965 to determine the optimum time near midseason to apply nitrogen fertilizer for greatest yield. Internode elongation was used as a guide to estimate proper morphological stage of development for the optimum tune to apply nitrogen. During the 3 years of study all three varieties had grain yield increases of over 1,120 kg/ha that could be attributed to applying midseason nitrogen at the proper time during panicle initiation. Topdressing nitrogen at midseason was found to be most effective when 50% of the plants had elongating internodes equal to or in excess of 12.8 mm for Vegold, 39.7 mm for Nato, and 32-1 mm for Bluebonnet 50.
显示更多 [+] 显示较少 [-]