Effects of Sowing Date, Seed Rate and Row Spacing on Agronomic Traits and Seed Yield of Canola Cultivar RGS003 in Gonbad Areas

Effects of sowing date, seed rate and row spacing on agronomic traits, sclerotinia stem rot disease and seed yield of canola (RGS003 cultivar) was evaluated in an experiment at Agricultural Research Station of Gonbad during 2003–2005. The experiment was a split plot factorial arranged in a RCBD with four replications. Three sowing dates (6 Nov., 21 Nov. and 6 Dec.) were as main plots and three seed rates (4, 7 and 10 kgha-1) and two row spacing (12 and 24 cm) were subplots in a factorial form. The pre-flowering growth, plant height, height to first stem and secondary stems decreased with delay in sowing date. The 10 kg seed rate×24 cm row spacing treatment had the highest plant height and height to first stem (134.3 and 46.8 cm, respectively), the lowest secondary stems (3.86 per plant) and resistance to lodging (7.79) and the highest sclerotinia stem rot disease percent (10.88%). The first sowing date had the highest seed yield, because of good temperature conditions of beginning of the growth season and seedling sooner standing. The mean seed yield of the first, second and third sowing dates was 3512, 2827 and 2742 kgha-1, respectively. In the first year of experiment the seed yield decreased with increase of seed rate because of more lodging, whereas there was not a such trend in the second year of experiment. The seed yield decreased with increase of row spacing. The mean seed yield of 12 and 24 cm row spacing was 3158 and 2896 kgha-1, respectively. Finally with regard to two year results of experiment, 6 Nov. sowing date, 7 kgha-1 seed rate and 12 cm row spacing are recommended for canola planting in the area