Effect of seed priming, plant density and planting date on silage corn yield in summer delayed planting

To evaluate the effect of seed priming on plant establishment and to determine the optimum planting date and plant density of silage corn، SC 704، in summer late planting، an experiment was carried out as split-split plot based on randomized complete block design with four replications in Agriculture Research Center of Gharahkeil، Qaemshahr، Mazandaran Province، Iran، during two years، 2010 and 2011. The experimental factors were including two levels (27 July and 7 August) of planting dates as main plots، two levels of plant density (7 and 9 plants per m2) as sub-plots and four levels of seed priming (pure water، PEG-8000، KNO3 and control) as sub-sub-plots. Results showed that forage dry yield and ratio of ear to total dry weight were higher in 2010 than 2011. With the delayed planting، forage dry yield and ratio of ear to total dry weight had decreased 31. 7% and 18. 2%، respectively. Furthermore، forage dry yield had increased 21. 4% with the increasing of plant density. The seed priming with PEG also increased the ratio of ear to total dry weight. In total، results of this research indicated that the seed priming with PEG using late summer planting in August and density of 90000 plants per ha is possible to produce the high quality forage in silage corn. Keywords Seed priming; Density; Planting date; Silage corn