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Silk Development and Kernel Set in Maize as Related to Nitrogen Stress
Author(s) -
DeBruin Jason L.,
Hemphill Bryce,
Schussler Jeffrey R.
Publication year - 2018
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci2018.03.0160
Subject(s) - silk , grain yield , zea mays , biology , horticulture , kernel (algebra) , nitrogen , mathematics , zoology , agronomy , materials science , chemistry , combinatorics , composite material , organic chemistry
Nitrogen deficiency limits yield in maize ( Zea mays L.) through reduced kernel number. A day‐by‐day investigation of silk emergence and kernel establishment has not been conducted to determine when the reduction occurs. A field study was established near Adair, IL, in 2013 and Sciota, IL, during 2014 to investigate the effect of N deficiency on silk number per ear (SPE) and kernel number per ear (KPE). Three N treatments (0 [0N], 56 [56N], and 201 kg N ha −1 [201N]) and two DuPont Pioneer hybrids (P1395HR and P1498HR) were tested. The 0N treatment reduced specific leaf N by 33%, grain biomass by 35%, and KPE by 21% in 2013 and specific leaf N by 49%, grain biomass by 58%, and KPE by 50% in 2014, compared with 201N. Reduced N status had no effect on spikelet number in 2013 but reduced spikelet number by 7% in 2014. Nitrogen stress had no influence on the rate of silk emergence in 2013 but reduced silk emergence by 142 SPE d −1 in 2014. Compared with 0N, 201N increased the rate of KPE establishment by 67 KPE d −1 in 2014. Over 2 yr and three N rates, >76% of the silks emerged within 1.6 d and 97% of the kernels were established in 1.9 d. Kernel number was reduced under N deficiency by (i) kernel establishment from emerged silks, (ii) emerged silk number, and (iii) spikelet number. Alleviation of N stress by the R1 growth stage would effectively maintain optimum SPE, KPE, and yield potential.