Resumen de How to improve yield and quality of potatoes: effects of two rates of urea N, urease inhibitor and Cytozyme nutritional program

I.H Khan, M Zaman, M.J Khan, M. Iqbal Khan, M.N Babar

• A field experiment was conducted to assess the efficiency of urea applied with urease inhibitor [N-(n-butyl) thiophosphoric triamide (nBTPT- trade-name Agrotain®), and organic compound (Cytozyme) in minimizing abiotic plant stress in a potato (Solanum tuberosum L.) in Dera Ismail Khan, Pakistan in 2010-2011. The nine treatments of control (no N or Cytozyme), urea applied at 200 and 300 kg N ha-1, Agrotain treated urea applied at 200 and 300 kg N ha-1, urea-200+Cytozyme, urea-300+Cytozyme, Agrotain treated urea-200+Cytozyme, and Agrotain treated urea-300+Cytozyme, were replicated 5 times. Potato growth, yield and quality were significantly influenced by urea applied with Agrotain and Cytozyme. Agrotain treated-urea-200 with Cytozyme resulted in maximum plant survival (91%), plant height (48 cm), plant canopy (61 cm) and the number of stems per plant (3.9 stems) compared to urea alone. Agrotain-treated urea applied at 200 and 300 kg N ha-1 increased potato yield by 46% and 42%, respectively, compared to urea alone. Cytozyme with urea @ 200 and 300 kg N ha-1 increased potato yield by 53% and 35%, respectively, comparing to potato crops receiving urea at the two N rates. Tuber yield improved by 14% when Cytozyme was applied with Agrotain-treated urea at 200 kg N ha-1. Cytozyme and urea applied with Agrotain treated urea-300+Cytozyme produced 33% of large tubers, followed by 31% of medium tubers with urea-200 and Agrotain treated urea-200+Cytozyme. Our results demonstrate that urea applied at 200 kg N ha-1 with either Agrotain or with Cytozyme have the most potential to enhance potato yield.