The 2012 ASHS Annual Conference

Romaine lettuce is considered as one of the nutrient-dense lettuce varieties with excellent source of vitamins and minerals. However, inadequate information is available on nutritional status of the crop, and tissue macro- and micronutrient standards for optimal quality produce. Therefore, the study was conducted to investigate the impact of macro and microelement stress on the nutritional values of Romaine lettuce (Lactuca sativa L. var. longifolia), and to generate data on tissue elemental content at various stages of nutrient stress. Plants were grown by providing mM concentration of macro- (N, P, K, Ca, Mg, and S) and microelements (Fe, Mn, B, Cu, and Zn) for control (complete treatment) and the rest were deprived of an element under static hydroponic system in a glass greenhouse. The plant tissues sampled at two different stages (early and late), significantly declined in value in response to the deprived macro- or micronutrient. The sensitivity of lettuce to a particular element based on number of days for the development of visual deficiency symptoms differs with respect to a particular deprived macro or micronutrients. The shoot fresh and dry mass declined significantly, more so at the late deficiency stage. Images of visual deficiency symptoms of macro- and microelements were chronologically documented in the order of appearance for each deficient element. The tissue standards and values associated with various stages of deficiency were also documented. Compared to the nutrient deprived plants, the rate of elemental uptake and partitioning was significantly greater in normal plants.