Molybdenum as a Plant Nutrient: VIII The Effects of Different Molybdenum Levels and Nitrogen Supplies on the Nitrogen Fractions in Cauliflower Plants Grown in Sand Culture
PREVIOUS papers in this series described the effects of different levels of molybdenum on the growth and on the ascorbic acid, chlorophyll, molybdenum, sugar, nitrate and total nitrogen contents of cauliflower plants grown in sand cultures with two levels of nitrate (1, 2, 3). A later paper (4) presented the results of similar investigations, on the effects of different molybdenum levels given in the presence of different types of nitrogen supply. It was shown that the appearance of whiptail symptoms in molybdenum-deficient plants was independent of the form of nitrogen supply given. This paper presents results obtained for various nitrogen fractions, which, except for adenine, were determined in the same plants as those for which the results previously reported were obtained. Results of investigations on amino acid constituents by chromatography on filter paper are also given; they relate to plants grown in the experiments described previously and to plants grown on other occasions.