study of the effect of planting date and plant density on yield, developmental rate and agronomical traits of 2 triticale genotypes

in order to determine the best planting date and seeding rate of two triticale genotype in mashhad climate condition on 2007-2009 growing season, an experiment was carried out, using a split-plot design based on randomized complete block design with three replication, at torogh agricultural research station, mashhad, iran. main plots devoted to five seeding dates and factorial combination of three seeding rate and two triticale genotypes (et-79-17 and et-82-15) were as split plot. the result of combined analysis showed that, the effect of planting date on grain yield, biological yield, total tiller number per plant, fertile tiller number per plant, tiller fertility percentage, days to heading and duration of grain filling was significant. the highest grain yield was recorded from second planting date (october 22) and delay in planting date from second planting date (october 22) to fifth planting date (december 6) decrease grain yield about 29%. the longest days to heading and maturity was related to the first planting date and the shortest was related to the fifth planting date, the grain filling period was decreased with in the delayed planting date. the developmental rate was increased in the delayed planting date, although growing period was decreased. the highest number of tiller per plant was related to the second planting date and the lowest number was related to the fifth planting date. the highest percentage of tillers fertility was related to the third planting date and the lowest was related to the fifth planting date. in the other hand, the effect of plant density on the total tiller per plant and the number of fertile tiller was significant. with the increase of plant density the number of tiller per plant, the number of fertile tiller and the percentage of tiller fertility were decreased. furthermore the effect of plant density on the grain yield was not significant, so with considering the economical issues of triticale production and to decrease the production costs it seems that the lowest level of plant density (250 seed per m2) is sufficient. there was no significant difference between the tow triticale genotypes regarding the grain yield and the other studied traits.