Effect of different organic manures and fertilizers on growth and yield of knol-khol (Brassica oleracea var. gongylodes L.)

A field experiment was carried out to investigate the effect of different manures and fertilizers on the growth and yield of knol-khol (Brassica oleracea var. gongylodes) at Dr. Purnendu Gain Field Laboratory of Agrotechnology Discipline, Khulna University, Khulna from November 2014 to February 2015. The single factor experiment comprised of different types of fertilizers and manures viz., T₀ (Control), T₁ (Recommended doses of NPK), T₂ (Cow dung), T₃ (Vermicompost), T₄ (Poultry manure), T₅ (50 % Cow dung + 50 % NPK), T₆ (50% Vermicompost + 50% Cow dung), T₇ (50% Vermicompost + 50 % Poultry manure) and T₈ (25% Cow dung+ 25% Vermicompost+ 25% Poultry manure + 25% NPK). The Experiment was laid out in Randomized Complete Block Design (RCBD) with four replications. The maximum plant height was obtained from the treatment T₁ at 25, 35 and 45 Days after transplanting (DAT). The maximum spread of canopy was 36.75 cm, 52.50 cm and 66.05 cm from the treatment T₃, T₇ and T₂, respectively. The maximum economic yield (21.92 t/ha) and biological yield (40.083 t/ha) were found in the treatment T₁ and T₇, respectively. Highest benefit cost ratio (3.07) was obtained from the treatment T₁whilethe minimum (0.57) was obtained from T₃ which indicates that high cost of vermicompost affect net return severely. Although, T₁ produced maximum benefit cost ratio, the treatment T₄ and T₂ are very close to T₁ and also statistically similar. So, we can consider poultry manure and cow dung for our soil health, environmental benefits and ecological safety.