Effect of sowing date, nitrogen fertilizer and row space on yield and quality of sugar beet crop

Two field trials were carried out to study 18 reatments representing three sowing dates (1st October (Oct. ), 15th October (Oct.) and Ist November (Nov.), three nitrogen rates (65, 80 and 95 kg N/fed.) and two row spaces (15 and 25 cm). Treatments were distributed randomly in a split-split plot design with four replicates. Sowing dates were assigned in the main plots, nitrogen fertilizer levels were assigned to the sub plots and row spacing were randomly distributed in the sub-sub plots. Results showed that sowing on 1st Oct. was the best than other treatments in sucrose %, leaf area index, leaf/weight ratio leaves dry weight, top yield, root yield, and sugar yield (ton/fed.) in the two seasons and root diameter, purity%, root fresh weight as well as top yield in the 2nd season. Sowing date of 1st Oct. was suparior for in purity% and total soluble solids in the 1st and 2nd seasons, respectively. Sowi ng date of 1st Nov. surpassed the other dates in root length in both seasons as well as root diameter, root fresh weight and total soluble solids in the 1st season. Increasing nitrogen fertilizer level up to 95 kg/fed surpassed other levels in leaf area index leaves dry weight, leaf/weight ratio, root length, diameter and root fresh weight, total soluble solids, sucrose and purity% as well as top and root yields (ton/fed.) in both seasons. On the contrary, sucrose and purity% as well as sugar yield decreased in both seasons. Increasing row spacing up to 25 cm surpassed the narrawer distance in leaf area index, leaves dry weight, leaf/weight ratio, root length, diameter and root fresh weight, total soluble solids, sucrose and purity% as well as top, root and sugar yields (ton/fed.) in both seasons. The highest values of root yield (47.75 and 47.05 ton/fed.) was obtained from the interaction between sowing date of 1st Oct. with the application of 95 kg N/fed. and planting in 25 cm row spacing in both seasons. Highest sugar yield (7.98 and 7.74 ons/fed.) was recorded from the interaction between sowing date of 1st Oct. with the application of 80 and 65 kg N/fed. and using 25 row spacing in the 1s and 2 nd season