Withholding Phosphorus as a Conservation Measure for Vegetable Plants

Abstract

Abstract Two experiments were conducted to test the hypothesis that plants in the vegetative state would not succumb as rapidly to low light intensities if they had no phosphorous available as the resulting restriction in growth would permit stored photosynthate to be available for plant maintenance. The first used Peperomia obtusifolia ‘Variegata’ as the test plant. The rooted cuttings were received on December 22, 1965, and potted in propagator’s sand. They were grown in sand cultures to the surface of which a mineral nutrient solution was applied daily with the leachate allowed to drain away. The mineral nutrient solution contained in millimoles per liter, 5, 6, 1, and 1 of Ca(NO3)2, KNO3, KH2PO4, and Mg-SO4, respectively. Two ppm of Fe were added as a chelate (Fe 138) and trace elements were added as usual for a solution culture according to the recipe of Hoagland.