Effect of two periods of irrigation on some Traits of inbred lines and Hybrids of Maize

A field experiment was conducted in Coll. of Agriculture-Abu-Graib during two autumn seasons 2011 and 2012. This was to study some of growth criteria, genetic-morphological yield components for hybrids and inbred lines of maize, and to determine the relationship between yield and system capacity constant ( SCC) under two periods of irrigation (5 and 10 days), in addition to determine genotypes that have high yielding ability under sufficient and in insufficient water. A factorial arrangement of RCBD with three replicated was used. The result showed that hybrid Zm607xCA17 gave highest mean of dry matter (16.73 t/ha) and the hybrid CA17xCA21 gave highest mean of leaf area (0.44 m2) and number of kernel per ear (380.60 kernel/ear), while the hybrid OH40xZm51 gave highest mean of kernel weight (286.00 mg/kernel) and the hybrid CA21xZm607 gave highest mean of grain yield (5.69 t/ha) under the period of irrigation 5 days. While under period of irrigation 10 days, the hybrid OH40xZm51 gave highest mean of leaf area (0.41 m2) and the hybrid OH40xCA17 gave highest mean of dry matter (15.01 t/ha) and the hybrid CA17xCA21 gave highest mean of number of kernel per ear (373.38 kernel/ear), while the hybrid Zm51xCA17 was superior in kernel weight (276.00 mg/kernel) and the hybrid CA21xZm607 was gave highest mean of grain yield (4.91 t/ha) during autumn season 2011. During autumn season 2012, the hybrid Zm51xCA17 was superior in leaf area (0.46 m2) and the hybrid CA17xCA21 gave highest means of dry matter and grain yield (17.81 t/ha and 6.69 t/ha) respectively, and the hybrid OH40xCA17 gave highest mean of number of kernel per ear (410.66 kernel/ear), while the hybrid Zm51xCA17 was superior in kernel weight (280.00 mg/kernel) under period of irrigation 5 days. While under the period of irrigation 10 days, the hybrid OH40xCA17 was superior in leaf area (0.43 m2) and the hybrid CA17xCA21 gave highest means of dry matter, number of kernel per ear and grain yield (15.35 t/ha, 379.66 kernel/ear and 5.38 t/ha) respectively, while the hybrid Zm51xCA17 gave highest mean of kernel weight (275 mg/kernel). We can conclude that OH40xZm51, OH40xCA17, CA17xCA21, Zm51xCA17 and CA21xZm607 were best hybrids when application of selection program for water stresses tolerance.