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Plant Nitrogen Status and Boll Load of Cotton
Author(s) -
Gerik T. J.,
Jackson B. S.,
Stockle C. O.,
Rosenthal W. D.
Publication year - 1994
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/agronj1994.00021962008600030011x
Subject(s) - petiole (insect anatomy) , malvaceae , gossypium hirsutum , fiber crop , biology , cultivar , main stem , gossypium , agronomy , nitrogen , human fertilization , yield (engineering) , horticulture , growing season , botany , chemistry , hymenoptera , materials science , organic chemistry , metallurgy
Nitrogen management is important in determining cotton ( Gossypium hirsutum L.) yield and fiber quality. Plant tissue tests are often used to estimate cotton N status and determine if further fertilization is needed during the growing season. This study was conducted to examine the relationship between plant tissue tests of petiole NO 3 concentration and leaf N content and cotton performance as measured by vegetative growth (i.e., leaf area) and boll load. Nitrogen rates of 0, 18, 36, 72, and 144 m M N pot −1 were applied at 2‐wk intervals beginning 13 and 26 d after emergence in 1987 and 1988 through boll maturity to a greenhousegrown cultivar, Stoneville 213. The strong relationship between leaf N and leaf area and boll number ( r 2 = 0.80 and r 2 = 0.89) 1 wk after first flower appearance suggests that the transition period between vegetative and boll development is a critical time to assess cotton's N status in relation to yield. Nitrogen deficits had little effect on boll weight, boll period duration, and number of main stem nodes. Although boll weight decreased with increasing N deficit, final boll weight of the high‐N plants were within 20% of the plants receiving low N supply. The relationship between leaf N and petiole NO 3 content, was best described by Y = a + bX C ; however, with this function only one‐half of the variation in leaf N was accounted for by variation in petiole NO 3 content ( r 2 = 0.48). Leaf area and boll number were poorly correlated with petiole NO 3 content. Leaf N content was a better predictor of cotton vegetative growth (as indicated by LAI) and boll number than petiole NO 3 content, particularly when measurements are made 1 wk after first flower.