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Postemergence Mortality and Barrenness of Two Maize Hybrids Affected by Tillage and Nitrogen
Author(s) -
Olness Alan,
Evans S. D.,
Harris K. R.,
Rinke J. L.,
Gooch S.
Publication year - 1990
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/cropsci1990.0011183x003000020004x
Subject(s) - udic moisture regime , tillage , loam , plough , agronomy , stover , biology , fertilizer , chisel , saccharum , zoology , field experiment , soil water , materials science , ecology , metallurgy
Tillage and/or fertilizer N by hybrid interactions in maize ( Zea mays L.) affect resource use efficiency. Our objective was to document these interactions for postemergent mortality (PEM) and barrenness of two maize hybrids, Pioneer Brand Hybrid 3906 (Pi 3906) and Dekalb‐Pfizer XL8 (De XL8). The PEM was measured in continuous tillage‐continuous maize‐N (CTMN) study in 1985 and 1986 and a continuous tillage maize‐soybean [ Glycine max (L.) Merr.I rotation (TMSR) study in 1986 and 1987. The CTMN and TMSR field experiments were conducted on a Tara silt loam (fine, silty, mixed Pachic Udic Haploboroll) and Doland silt loam (fine, loamy, mixed Udic Haploboroll), respectively, in a randomizedblock design. Tillage‐N combinations were moldboard plow (MP), chisel plow (CP), ridge till (RT), and no‐till (NT) with fertilizer (N) applied in the fall as anhydrous ammonia at 0, 5.6, 10.8, 16.4, and 22.7 g m −2 N, plus 0.9 g m −2 N applied as starter fertilizer. The PEM was recorded only for NT and MP tillage treatments, which had received 6.5 and 17.3 g m −2 N in the CTMN study and 18.0 g m −2 N in the TMSR study. Plant and emergence marker counts were recorded in two 9.2‐m row lengths at 2‐d intervals for 6 wk and thence weekly until harvest. Plant losses in De XL8 ranged from about 3 to 6% and 4 to 12% in the CTMN and TMSR studies, respectively. Plant losses in Pi 3906 ranged from 2 to 3% in both studies. The PEM of Pi 3906 with no‐tillage treatments was significantly less than that of De XL8, but not different from other tillage‐hybrid combinations. Plant barrenness at harvest decreased significantly as applied N rate increased only in De XL8; in 1986 (third year of CTMN study), barrenness generally decreased from greater than 40 to less than 10% as the intensity of tillage increased. Barrenness in Pi 3906 was unaffected by tillage.