Relationship between mo and Fe in Lucerne plants

Abstract The relationship between Fe uptake and Mo availability and its possible correlation with reduction of nitrates has been studied. Lucerne plants (Medicago sativa L.) were grown in hydroponic cultures in acid‐washed quartz sand and deionized water. The greenhouse environmental temperature ranged from 22–25°C. The pots were exposed to a light intensity of 8000 lux for 16 hours and to a dark period of 8 hours. The nutrient solution added to each treatment contained the same concentration of Fe and the following concentrations of Mo: 0, 12.5, 25, 50, 100 and 200 μg/ml. These solutions were added daily and for 90 days. It was found that the dry weight of controls was slightly higher than other treatments. The level of nitrates in plants, expressed both as concentration or total content, decreased with increasing Mo concentrations, i.e., the higher the Mo level available to the plant, the lower the nitrate concentration present in the tissue. As toxicity symptoms were not observed for the highest Mo con...