About Us | Help Videos | Contact Us | Subscriptions



This article in AJ

  1. Vol. 75 No. 6, p. 941-947
    Received: Dec 30, 1981

Request Permissions


The Effect of Root Temperature and NO−3/NH+4 Ratio on Strawberry Plants. I. Growth, Flowering, and Root Development1

  1. Ruth Ganmore-Neumann and
  2. U. Kafkafi2



The purpose of this work was to study the effect of various NO3/NH+4 ratios in the nutrient solution at various root temperatures on strawberry (Fragaria ananassa) plants. The results could lead to a suitable NO3/NH+4 ratio of the fertilizer solution to be applied in field-grown strawberry plants in different seasons on sandy soils.3 Strawberry plants were selected for uniformity and transferred individually to a 1 L container through which the nutrient solution was flushed at a rate of 1 L/h. The total N concentration was 7 me/L. Five ratios of NO3/NH+4, 7/0, 5/2, 3.5/3.5, 2/5, and 0/7, respectively, were used, each at four root temperatures (10, 17, 25, and 32°C). Constant NO3/NH+4 ratio, constant total nutrient concentration, and constant pH (6.2) were maintained for 8 weeks. There is a general decline in root growth with increasing root temperature when a single source of N is supplied. This decrease is followed with a decrease in the sugar concentration of the roots. At 32°C root temperature gradual increase in the NH+4 fraction in the nutrient solution is followed by gradual deterioration of the plants to a complete death at 100% NH+4. This death is related to the depletion of sugars and possible shortage of oxygen in the root cells due to NH+4 metabolism in the root.

  Please view the pdf by using the Full Text (PDF) link under 'View' to the left.

Copyright © .