EFFECT OF SULFUR AND MOLYBDENUM LEVELS ON GROWTH, NITRATE-ASSIMILATION, AND NUTRIENT CONTENT OF PHALARIS

An experiment was conducted with Phalaris aquatica L. cv. Sirolan unde r hydroponic conditions in the glasshouse at constant temperature of 2 5 degrees C and natural sunlight. Plants were grown in double pot syst em with four sulfur and three molybdenum levels along with all the maj or- and micro-nutrient elements. There was increase in growth, nitrate -reductase activity and contents of most of the nutrient elements at a ll levels of sulfur and 1.68 mu g/L molybdenum. Molybdenum at 3.36 mu g/L level inhibited growth and nitrate-reductase activity and decrease d concentration of nutrient elements in plant. The inhibitory effect o f higher level of molybdenum is perhaps mediated through its role in t he nitrate-reductase.