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Physiological and Morphological Response of a Drought‐Tolerant Maize Hybrid to Agronomic Management
Author(s) -
Lindsey A. J.,
Barker D. J.,
Metzger J. D.,
Mullen R. W.,
Thomison P. R.
Publication year - 2018
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/agronj2018.01.0034
Subject(s) - interception , biology , agronomy , hybrid , drought tolerance , sowing , stomatal conductance , photosynthesis , population , specific leaf area , water use efficiency , phenotypic plasticity , irrigation , botany , ecology , demography , sociology
Core Ideas Variability in morpho‐physiological traits was documented between hybrids. Hybrid responses to agronomic management differed in magnitude for select traits. Traits that improved light interception and utilization were correlated to yield.Concerns about limited water availability have led to the release of a new generation of drought‐tolerant maize ( Zea mays L.) hybrids, but limited research is available on the morphological and physiological traits that may confer tolerance in these hybrids and the plasticity of these traits under different agronomic management practices. A field study was conducted in 2013 and 2014 at three Ohio locations to investigate physiological responses of a drought‐tolerant hybrid (P1352) and a conventional hybrid (P1184) to plant population (59,000 or 104,000 plants ha −1 ) under May and June planting dates, and correlate physiological traits to grain yield. Measurements included net photosynthetic rate, stomatal conductance, light interception, specific leaf area (SLA), and grain yield. Despite favorable conditions for maize growth, the drought‐tolerant hybrid maintained similar or greater photosynthetic rates (8–10% greater) with a lower stomatal conductance (22–30% less) compared with the conventional hybrid. Across site‐years, the drought‐tolerant and conventional hybrid exhibited similar morphological and physiological responses to plant population and planting date with some variance in magnitude of response for specific traits. The drought‐tolerant hybrid produced greater biomass and SLA than the conventional hybrid, exhibited greater light interception than the conventional hybrid (97 vs. 95%, respectively), and produced 2.5% greater grain yield than the conventional hybrid. Traits correlated to grain yield included plant height, light interception, photosynthetic rate, SLA, and chlorophyll fluorescence. Future evaluations in both stressed and non‐stressed conditions should be conducted with additional hybrid pairs to provide further validation.