Impact of Phosphorus Levels on Vegetative Growth and Seed Yield of Lettuce (Lactuca sativa L.) Cultivars

The study was conducted to investigate the effects of different phosphorous levels on the growth and seed yield of the lettuce (Lactuca sativa L.). Two lettuce varieties namely Grand Rapids and Romaine were tested on various phosphorus fertilizer levels i.e. 60 kg and 80 kg per hectare using Randomized Complete Block under factorial Design (RCBD). The treatment without phosphorus was seed parameters as well as sensory evaluation including crispiness and color were examined after interval of each 10 days. We report that the increase in the phosphorus fertilizer has positive effects on yield, ground cover and shelf life of both varieties; however Grand Rapids significantly showed superior performance than that of Romaine. Furthermore, Romaine developed seeds not observed in case of Grand Rapids cultivar seemingly due to insufficient chilling hours required for phase transition. Further investigations are suggested at molecular level to decipher the components involved in better yield and seed development in both varieties tested.