THE EFFECTS OF DIFFERENT NITROGEN DOSES ON TUBER YIELD AND SOME AGRONOMICAL TRAITS OF EARLY POTATOES

Abstract

This study was conducted to determine the effects of different nitrogen rates on tuber yield and some agronomical traits of early potatoes grown in 2011 and 2012. The field trial was conducted at the experimental field of Cukurova University, in the Randomized Complete Block Designs, with three replications, with Marfona a medium early table potato. Zero, 40, 80, 120, 160, 200, 240, 280, 320 and 360 kg ha -1 pure nitrogen doses were applied. According to the mean values of two years, the total tuber yield was 24.0 ton ha -1 in the control plot. The highest yield per hectare (53.31 ton ha -1 ) was obtained from the 240 kg ha-1 N applied plots. Beyond 240 kg ha -1 peak, as the dose was increased, the tuber yield was decreased. In addition, the marketable tuber yield ratio was 95.60 % with 0 N dose. When the N dose increased to 200 kg ha -1 , the marketable tuber yield has also increased up to 97.41. After 200 kg ha-1 dose, the marketable tuber yield has started to decrease.