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The Effects of Nutrient Stress on the Growth and Composition of Spinach1


Fall and spring spinach experiments were conducted in the greenhouse in sand culture. Nutrient stress was produced late in the growth period by removal of N, P, K, Ca, or Mg from the nutritional regime. Nitrogen stress caused a general restriction in growth and chlorophyll concentration while dry weight was reduced by P and K stress only in the spring experiment. Element stress generally resulted in lower concentrations of that element in mature leaves in the fall and in both mature and immature leaves in the spring investigation. Redistribution generally occurred at a sufficient rate to prevent lower element concentrations in the fall but not in the spring study. K, Ca, and Mg accumulated in mature spinach leaves while N and P were found in higher concentrations in immature leaves.