CHANGES IN THE COMPOSITION AND RATE OF GROWTH ALONG THE DEVELOPING STEM OF ASPARAGUS

Abstract

Using field-grown material, the rate of growth and the chem. composition in successive zones along the developing stem of asparagus were detd. The measurements of growth rate were made upon a population of 116 individuals; the samples for the chem. determinations consisted of 20 to 30 stems each. The total solids or dry matter content was minimum in amount at a point several cm. below the tip in a zone slightly below the zone of maximum rate of elongation. From this zone of minimum solids content, solids increased in amt. toward both the base and the tip of the stalk. The total sugar content was minimum at the tip and increased rapidly downward to the zone of maximum rate of elongation, below which the rate of increase was less marked. Total N was maximum in amount at the tip, rapidly decreasing downward to a zone slightly below the zone of maximum rate of elongation, from which point the decrease in amount toward the base was much slower. Total N is lowest in the basal portion of the stem but increases rapidly in amt. in regions near the tip, where it always remains high in amt. as growth in length proceeds. The total amount per unit length of the stem does decrease near the tip as a result of its decrease in diameter with increase in height.