Effect of Fertility Levels and Varieties on Tuber Yield and Processing Quality of French Fry Grade Potato

A field experiment was conducted during rabi seasons of 2013 to 2014, at Amritsar in split plot design having three potato varieties (Kufri Frysona, Kufri Chipsona 1 and Kufri Surya) in main plot and four fertility levels (F1; 187.5 kg N/ha [N 93.7kg (planting) + N 93.7kg (earthing)] + 62.5 kg P2O5 + 62.5 kg K2O/ha soil application; F2; 187.5 kg N/ha [N 84.7kg (planting) + N 84.7 kg (earthing) + 2 foliar spray (2% urea) at 60 and 80 days after planting] + 62.5 kg P2O5 + 62.5 kg K2O/ha; F3; 270 kg N/ha [N 135 kg (planting) + N 135 kg (earthing)] + 62.5 kg P2O5 + 90 kg K2O/ha; F4; 270 kg N [N 126 kg (planting) + N 126 kg (earthing) + 2 foliar spray (2% urea) at 60 and 80 days after planting]

+ 62.5 kg P2O5 + 90 K2O kg/ha.) in sub plots with three replications. French fry grade (FFG) tuber yield was significantly higher in F₁ than F₃, F₄ and F₂. Tuber dry matter and French fry color were in highly acceptable range throughout the fertility treatments. Significantly more number of Chip grade (45-75mm), processing grade (>45mm), total and French fry grade tubers (>75mm) were noticed in Kufri Chipsona 1 and Kufri Surya, respectively. Kufri Surya and Kufri Frysona produced significantly higher FFG tuber yield, whereas chip grade tuber yield was significantly highest in Kufri Chipsona1 (18.8 t/ha). Tuber dry matter was significantly higher in Kufri Frysona and Kufri Chipsona1 than Kufri Surya.