Effect of potassium nitrate and sucrose on the yield of onion (Allium cepa L.) plants

Onion bulb is the second most consumed vegetable in Colombia and is mainly produced in Boyaca, one of the departments in the country. The aim of this research was to evaluate the effect of the application of KNO and sucrose in onion bulb plants during the bulb formation. The research was conducted in Duitama, Boyaca. The plant material was hybrid onion 'Granex 2000 FT. The culture was handled using agronomic practices in the region. The experimental design was completely randomized with nine treatments corresponding to the application of KNO and sucrose individually and in combination, with three replications. The application of treatments began at 62 days after transplantation and until the beginning of bulb filling, by foliar spraying. The response variables were relative chlorophyll index, equatorial diameter, fresh weight and dry bulb and yield. Analysis revealed significant differences between the application of KNO, and sucrose with respect to the non-application for the relative chlorophyll index, equatorial diameter, fresh and dry weight and performance. Treatment of 1 % KNC)(3)+ 0.5% sucrose showed the best performance in variables like dry bulb with 201 +/- 4.2 g/bulb, fresh weight with 15 +/- 0.16 g/bulb and yield with 59.3 +/- 0.46 t ha(-1), versus non-application that present values of 173.5 +/- 4.2 g/bulb, 13.9+0.5 g/bulb y 52.1+1.01 I ha"' respectively. The application of KNO and sucrose is an alternative for improving quality and yield in onion bulb under the study conditions.