بررسی تأثیر تراکم بوته بر عملکرد و اجزای عملکرد در هیبریدهای مختلف ذرت تحت شرایط اقلیمی شهرستان ایوان

To investigate the effect of plant density on seed yield and its components of maize hybrids, a split plot experimental based on randomized complete blocks design with three replications was carried out in Eyvan Town, during 2008-2009 season. Maize hybrids of Ksc 704, Ksc 604 and Ksc 647 arranged as factor A in main plot and plant density at 5 levels, including 5.5, 7, 8.5, 10 and 11.5 plants per square meter were allocated in sub plots as factor B. Analysis of variance showed that the effect of density on plant height and ear length, was significant at the 5% probability level and the impact of these two factors on other characteristics was significant at 1% probability level. The maximum number of rows per ear was obtained in hybrid of Ksc 604 and density 5.5 plants per square meter with 15.06 and 15.13 respectively. The highest and lowest grain numbers per ear was produced in Ksc 704 (375.8) and Ksc 604 (367.3) respectively. The highest 1000 seed weight obtained in Ksc 604 with 278.5 gr and the lowest observed in Ksc 704 with 269.4 gr. Results showed that, with increasing of plant density 5.5 to 11.5 plants per square meter, 1000 seed weight was decreased. According to the results, the hybrid of Ksc 704 the highest grain yield (9196 kg. ha-1) and density of 10 plants per square meter (8696 kg. ha-1) are the best treatments in this experiment.