EFFECTS OF NITROGEN FERTILIZATION AND HARVEST TIME ON ROOT YIELD AND QUALITY OF FODDER BEET (Beta vulgaris var. crassa Mansf.)

The effects of five nitrogen rates (0, 50, 100, 150 and 200 kg ha-1) and four harvest times (1 September, 15 September, 1 October and 15 October) on root yield and yield components of fodder beet (Beta vulgaris var. crassa Mansf.) were evaluated under Isparta conditions in the 2007 and 2008 growing seasons. Nitrogen rates and harvest time significantly affected most of the yield components determined in fodder beet. Nitrogen applications increased root yield, dry matter yield, crude protein content, crude protein yield, root diameter and root length but decreased ADF and NDF contents of roots. Crude protein content decreased with advancing times while root yield, root dry matter yield, crude protein yield, root diameter, root length ADF and NDF contents of roots increased. Based on these results, 150 kg per hectare nitrogen treatments and third harvest time can be recommended for similar ecelogical conditions because of high crude protein yield in fodder beet.