MOLYBDENUM NUTRITION OF ALFALFA

Abstract

Purification and cultural methods for the study of the Mo nutrition of alfalfa are described. The effect of Mo on yield and partial chemical composition of alfalfa was studied in nutrient cultures when nitrates were supplied and also when atmospheric N was utilized. Plants which received nitrates but no Mo accumulated nitrates in their tissues. Leaves were chlorotic and lower leaves became necrotic and abscissed. The Mo-deficiency symptoms were more severe when plants were forced to utilize atmospheric instead of nitrate N. Plants supplied with Mo contained from 47 to 92% more total N and produced yields which were significantly higher than those of untreated plants. The succinic dehydrogenase activity of deficient plants was much lower than that of normal plants. A concn. of one part per billion Mo in nutrient solns. was sufficient for maximum growth.