Comparison of different hybrid maize seed size with smaller under sieve size in standard germination, cold, accelerated ageing and electrical conductivity tests

With respect to this fact that small under sieve seeds comprise about 15-16% of Iran maize seed production, it is possible to produce feed stuff from these seeds, especially in non stressful areas. In order to compare germination and vigor indices of small under standard sieve (6mm) seeds of hybrid maize (Zea mays L. Cv. Single Cross 704) in laboratory, this study was carried out in 2010 in the central seed analysis laboratory of seed and plant certification & registration institute in Karaj. In standard germination, cold, accelerated ageing and electrical conductivity tests, germination and vigor indices of flat, medium and round seed shapes were compared with smaller sieve size seeds. The difference of germination percent of various seed shapes in cold vigor test were significant, while in standard germination and accelerated ageing tests there was not any significant difference between germination percent of various seed shapes. Totally germination percent of standard germination was higher than two other tests. Nevertheless, root, shoot and plant length, dry and wet weight, and seed length and weight vigor indices of under standard sieve seeds in standard germination test was significantly less than other seed shapes. Germination percentage of under sieve seeds of accelerated ageing test was more than standard maize seed shapes. Germination percentage, root, shoot and plant length, dry and wet weight, and seed length and weight vigor indices of under standard sieve seeds in cold test were significantly less than flat, medium and round seed shapes. Electrical conductivity of flat, medium and round seed shapes was significantly less than under standard sieve seeds.