Effect of seeding rate on yield and yield components of durum wheat cultivars in cotton-wheat cropping system

This research was carried out in experimental field of Southeastern Anatolia Agricultural Research Institute in randomized split bloc design with three replications for three years (2004 - 2005, 2005 - 2006 and 2006 - 2007 growing seasons). The objective of this study was to determine the effects of seeding rates on grain yield and yield components of two durum wheat cultivars (Aydin-93 and Firat-93) under permanent bed planting in cotton–wheat cropping system. Six seeding rates (50, 150, 250, 350, 450 and 550 seed per m-2) were tested. Seeding rate affected grain yield and yield components except for protein content, but its effects is being altered from year to year. The results revealed that 253 seed per m-2 (111 kg ha-1) proved as predicted optimum seed rate; producing highest grain yield (5162 kg ha-1) as regards averages of all years. Among varieties, significant differences were found for yield and yield parameters.   Key words: Chlorophyll content, durum wheat, grain yield, grain quality, seeding rate, permanent bed planting.