Effect of spacing and biofertilizers on growth and nutrients of stevia (Stevia rebaudiana Bertoni)

A field experiment on effect of spacing and bio fertilizers on growth and nutrients of stevia (Stevia rebuadiana Bertoni.) was conducted during kharif seasons of 2006 and 2007. The experiment was laid out in split plot design with main plot with four spacing levels (30 cm × 20 cm, 30 cm × 30 cm, 45 cm × 20 cm and 45 cm × 30 cm) and sub-plot treatments included six bio-fertilizer based nutritional trials (100% NPK (recommended dose: 60:30:45 kg/ha) 75% N + PK + Azotobacter (Azoto), 100% N + PK + Azoto, 75% N + PK + Azospirillum (Azosp), 100% N + PK + Azosp; and control (no fertilizers). The experiment was laid out in split plot design with three replications and 24 treatment combinations. Significantly, higher spread was recorded in the spacing of 30 cm × 30 cm, over other spacing levels, at 60 and 90 DAP. However, the spacing of 30 cm × 20 cm, 45 × 20 cm and 45 × 30 cm recorded comparable plant spread at 30 DAP. The spacing of 30 cm × 30 cm recorded significantly higher number of leaves, than other spacing levels, at 30, 60 and 90 DAP. Nitrogen and phosphorus (P) content did not differed significantly due to spacing levels during both the years of experimentation. Significantly higher potash content of 1.36% was recorded in the spacing of 45 cm × 30 cm. Higher plant height, plant spread(24.06 cm²/plant), more number of leaves and number of branches were recorded in the treatment that received 100% N + PK + Azotobacter and 100% N + PK + Azospirillum at all the growth stages. Higher nitrogen content was recorded in the treatment that received 100% N + PK + Azotobacter (1.56%) than other treatments. Significantly, higher phosphorous content was recorded in the treatment that receives 100% N + PK + Azotobacter (0.074%) and higher potash content (1.42%) than other treatments. Significantly, higher N content of 1.64% and K content of 1.49% was recorded in the treatment combination 30 cm × 20 cm with 100% N + PK + Azotobacter than other treatment combinations.