Evaluation of soil and foliar application of nitrogen at different growth stages on yield and yield components of sugar beet cultivars

In order to evaluation the effects of different application methods of nitrogen fertilizer on sugar beet yield, an experiment was conducted in farms of agriculture faculty of Islamic Azad university, Tabriz branch in 005. A randomized complete block design based factorial with three replicates used for three cultivars (7, PP, and IC) and three nitrogen application methods (seedbed applying of nitrogen, spraying at 6-8 and 4-6 leaf stages). Results showed that applying methods and cultivars had not significant effect on root and sugar yield, but on sugar percentage. Nitrogen spraying on P increased root yield more than other cultivars. Among N applying methods, nitrogen spraying was more effective than others. Soil application of nitrogen increased sugar yield in 7 and IC cultivars, whereas in PP, the most effective method was nitrogen spraying in 4-6 leaf stage. Nitrogen spraying in PP for increasing root yield, and nitrogen spraying at 4-6 leaf stage in PP, and seedbed applying of nitrogen fertilizer in 7 and IC cultivars for increasing sugar yield was recommended.