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Effects of Nitrogen Rates and Plant Spacing on Sunflower Seed Yields and Other Characteristics 1
Author(s) -
Massey John H.
Publication year - 1971
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/agronj1971.00021962006300010043x
Subject(s) - sunflower , nitrogen , helianthus annuus , yield (engineering) , agronomy , field experiment , horticulture , chemistry , mathematics , biology , materials science , organic chemistry , metallurgy
Field experiments were conducted to determine effects of nitrogen and plant spacing on sunflower ( Helianthus annuus L .). Nitrogen rates were 0, 56, 112, and 168 kg/ ha, and plants were spaced 15, 30, and 46 cm apart within rows 1.1 m wide. Nitrogen at 56 kg/ha increased seed yield, grams of seed per head, seed size, and head diameter 653 kg/ha, 17.7 g, 1.9 g/200, and 2.2 cm, respectively, as compared to nontreated plots. Plant height was increased 11 cm and stem diameter 4 mm by 56 kgN/ha. No further increases resulted from additional N. Nitrogen did not affect number of leaves per plant. Seed yield decreased, but yield per head and head diameter increased with each 15‐cm increase in plant spacing. Seed were larger at 30‐ and 46‐ than at 15‐cm spacing. Spacing did not affect plant height or number of leaves, but stem diameter increased with wider spacing. There was no significant interaction between nitrogen and plant spacing for any characteristic studied.