Seed Size of Maize Hybrids: I- Effects on Emergence and Seedling Traits under Different Salinity Levels

There has been some concern about using small seeds that may result from seed position on the ear or poor growing conditions for seeding hybrid maize. This study was designed to investigate the effect of seeding three commercial maize crosses (Single Cross 2010, Three-Way Cross 310 and Three-Way Cross 321) with three seed sizes (large, medium and small) under seven salinity levels of irrigation water (Zero, 2500, 5000, 7500, 10000, 12500 and 15000 ppm). Emergence and seedling traits were recorded under controlled environment in a splitsplit plot, in a complete block design, with three replicates.The different salinity levels highly significantly affected germination (%), plumule length, radical length, plumule weight, radical weight and seedling weight. Such traits were, gradually, decreased in response to increasing NaCl concentration. Significant differences were observed in plumule length among the studied maize hybrids all over different seed sizes and salinity levels. A significant effect of interaction between salinity levels and maize hybrids was revealed for germination (%), plumule length and plumule weight. Different seed sizes of the hybrids significantly affected radical length and plumule weight. A significant interaction effect of salinity levels by seed sizes was revealed for plumule weight. There was a nonsignificant interaction of hybrids by seed sizes on any of the J.Agric.&Env.Sci.Alex.Univ.,Egypt Vol.6 (2)2007 118 studied traits. However, significant effects of three-way interaction (salinity x hybrids x seed size) were revealed on radical weight and seedling weight. The results suggested that sowing large seed sizes of the studied maize crosses could improve germination and seedling vigor associated with better germination vigor under high levels of irrigation water salinity.