In:
Agronomy Journal, Wiley, Vol. 105, No. 4 ( 2013-07), p. 1129-1141
Abstract:
Maize ( Zea mays L.) improvement in drought‐stress tolerance poses a great challenge as the global need for food, feed, fiber, and fuel increases. Seed companies are developing and promoting drought‐tolerant hybrids, but their physiological drought‐tolerance mechanisms are not well understood. The research objective was to investigate the plant traits related to yield improvement for similar maturity hybrids classified as either drought‐tolerant (non‐transgenic) or conventional at varying plant density (PD) (two levels) and N rates (four levels) over 2 site‐years in northwestern Indiana. Physiological measurements included photosynthesis ( A ), transpiration (E ), and leaf area index at multiple growth stages, as well as anthesis‐silking interval, potential kernel number, grain yield (GY) and its components. Intensive heat and drought stress occurred in the 30‐d period before and during flowering in 2012, but not in 2011. Overall, similar maturity drought‐ and non‐drought‐tolerant hybrids did not markedly differ in GY or most other traits, and hybrid responses to varying PD and N rates were similar. In both seasons, GY was impacted most by N rates. A complex N rate effect on A and E was tightly related to water supply (i.e., higher N had positive impact under non‐drought conditions). Hybrid differences in A and E were not significant at the leaf‐scale, but one drought‐tolerant hybrid had lower estimated cumulative A and E at the season‐long canopy scale. Under the non‐drought and specific‐drought conditions in these single‐location trials there was no indication that designated drought‐tolerant hybrids were more tolerant to high crowding intensity and/or low N stresses.
Type of Medium:
Online Resource
ISSN:
0002-1962
,
1435-0645
DOI:
10.2134/agronj2013.0066
Language:
English
Publisher:
Wiley
Publication Date:
2013
detail.hit.zdb_id:
1471598-3
Permalink