كليدواژه :
planting date , seed yield , oil sunflower , افتابگردان روغني , تاريخ كاشت , عملكرد دانه , كشاورزي , ارقام گياه
چكيده لاتين :
To study the effect of planting date on growth and development , grain yield and yield components of two oil sunflower cultivars an experiment was conducted at experimental farm of Islamic Azad University of Damghan in 2002. A factorial experiment with randomized complete block design and four replications were used. Combinations of two cultivars; Record and Zaria, with four planting dates; April -24 , May -7, May -21 and June -2 , were used as experimental treatments .Developmental stages including number of days from planting to emergence, heading, anthesis and physiological maturity and also stem diameter, plant height, head diameter, 100 seed weight, grain yield, biological yield, hares index, ratio of hull-kernel, ratio of shell - hull, peecentage of hollowness seed per head and percentage of birdʹs damage were evaluated.Record cultivars had significantly highest stem diameter, head diameter, 100 seed weight, grain yield and ratio of shell - hull at all developmental stages.Number of days from planting to heading and physiological maturity, stem diameter, number of seed per head, garin yield, biological yield, ratio of shell - hull and percentage of birds damage were significantly affected by planting date. The number of days from planting to heading, stem height, biological yield, harvest index and ratio of shell - hull were affected by planting date and cultivar interaction.The maximum (4237 kglha) and the minimum (3490 kg/ha) grain yield were obtained from second and fourth planting dates, respectively. The grain yield of Record cultivar was %14.8 higher than Zaria cultivar. With respect to results of this experiment conditions, planting Record cultivar in middle of April in Damghan regions is recommended.
