Absorption of Nutrient Ions by the Tomato Plant at Various Stages of Development

In studies with herbaceous annuals, it has often been observed that characteristic changes in metabolism and rate of growth are closely associated with certain stages in the development cycle (Loehwing, 1942, 1948, 1951; Murneek, 1937; Wittwer, 1943). Of particular interest have been changes accompanying synapsis and syngamy. One of the changes following these stages appears to be a marked acceleration in the rate of inorganic ion uptake from the substrate. Such accelerations have been shown to follow floral initiation and formation of the embryo in several plants including barley (Burd, 1919), corn (Hornberger, 1882; Jones and Huston, 1914), cotton (Olson and Bledsoe, 1942) and tobacco (Vladescu, 1934). Al though it has been reported that the largest increment in nutrient absorption by the tomato plant occurs during flowering and fruiting (Hester, 1938; Hester et al., 1951), this plant has apparently not been examined critically to determine whether two maxima are present within this period of stimulated uptake. This investigation was initiated to determine whether the rate of ion absorption by the tomato plant was correlated with particular stages in development