Effect of planting date on yield and germination indices of different shapes of hybrid maize seeds (Zea mays L. Cv. Single cross 704)

Abstract

Maize (Zea Mays L.) is the third most important crop after wheat and rice and is grown in more countries than any other crop in the world. This experiment was conducted to study of germination reactions of different shapes of hybrid maize (Zea mays L. Cv. Single Cross 704) to planting date and effect of planting date on yield and yield components. The study was carried out in 2012 at the seed and plant certification and registration institute in Karaj- Iran. The experiment in field was conducted in a randomized complete block designs with four replications. Also the experiment in laboratory was carried out in a factorial experiments based on completely randomized designs. The ration of maternal lines to paternal lines was 4:2, so that B73cms was used as the maternal line and Mo17 was used as the paternal line Treatments were included planting date (T1: 2 May., T2: 12 May., T3:28 May) and seed size (round, medium and flat).For separation and grading of round, flat and medium seeds respectively oblong (5.5 mm), round (7 mm) and round (6-6.25mm) sieves were used. Traits were studied including: yield and yield components, standard germination, Mean time to germination (MTG), Seedling vigor index length and Radicle emergence. Results showed that sowing date significantly effected on the number of seeds on rows, weight of 1000 seeds and yield. Main comparison indicated that with delay of planting date, normal seedling percentage and Seedling vigor length index and radical emergence were decreased and mean time to germination was increased.