The effect of sowing date on yield and yield components of cotton planted in ultra narrow rows and conventional rows

Cotton has been traditionally grown in rows spaced from 75 to 100 cm. Narrow row spacing have been found to increase yield potential in cotton due to better sunlight penetration and more uniform spacing of the cotton plants in the field. A field experiment was conducted to study the effect of planting date on yield and yield components of cotton with three planting systems at Sabzevar Agriculture and Natural Resources research center in 2013. This experiment was carried out as split plot design based on randomized complete block design with three replications. Factors were: planting date (Conventional (22 May) and late planting (22 June) as main plots and planting system; ultra narrow row spacing (20 cm (25 plant.m-2), conventional spacing (50 cm (10 plant.m-2) and broadcast seeding (8 plant.m-2) as subplots. The results showed that planting date and planting system had significant effect on plant height, number of bolls, boll weight and seed cotton yield. Late planting was decreased plant height (13.61%), number of boll (27.41%), boll weight (14.63%) and seed cotton yield (24.83%) as compared with conventional planting date. Narrow row spacing was better than other planting system for all traits. There was no significant difference between conventional spacing and broadcast seeding. Overall, ultra narrow spacing rows and conventional planting date (May 22) was the best treatment for achieving high yield in cotton under Sabzevar conditions.