Lettuce is a high value salad vegetable rich in minerals, vitamins and antioxidants.With the increasing awareness on ill effect of chemicals on human health and environment, the demand for residue free organic lettuce increased sharply. Traditionally, farmers are using farmyard manure (FYM) as source of nutrients for organic lettuce cultivation. But higher cost and scarcity of the animal manure forced farmers to search for alternate nutrient source for organic lettuce cultivation. An experiment was carried out to find out an alternate source of farmyard manure or substituted a portion to reduce the pressure on sole farmyard manure. The inputs namely farmyard manure and vermicompost were used sole as well as in combination of Azotobacter and Phosphate Solubilizing Bacteria containing biofertlizer (Azophos). Six numbers of treatments were laid out in randomized block design (RBD) with 4 replications. The seedlings of head type lettuce variety Great Lakes were transplanted in mid November for two years in the plot size of 3 m x 3 m. The pooled results revealed that all the yield attributing characters were influenced by treatments variation and the treatment combination comprised of FYM (10 t ha-1),vermicompost (2.5 t ha-1) and seedling inoculation with biofertilizer recorded the maximum number of leaves (18.42 plant-1) and chlorophyll content (39 SPAD value) and fresh weight of head (334 g plant-1). Application of vermicompost (5 t ha-1) inoculated with Azophos emerged as second best combination for most of the yield and yield attributing traits for organic lettuce production.
Key words: Organic production, nutrient sources, lettuce growth and yield.