Premium
Timing of Nitrogen Fertilization of Rice. II. Culm Elongation as a Guide to Optimum Timing of Applications Near Midseason 1
Author(s) -
Hall V. L.,
Sims J. L.,
Johnston T. H.
Publication year - 1968
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1968.00021962006000050002x
Subject(s) - panicle , nitrogen , oryza sativa , elongation , agronomy , nitrogen fertilizer , plant stem , yield (engineering) , human fertilization , grain yield , biology , field experiment , fertilizer , chemistry , materials science , ultimate tensile strength , biochemistry , organic chemistry , metallurgy , gene
Field studies were conducted with ‘Vegold,’ ‘Nato,’ and ‘Bluebonnet 50’ rice (Oryza sativa 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 time 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.