Allometric Growth Studies of the Carrot Crop: I. Effects of Plant Development and Cultivar

Abstract

The allometric equation Y = aW^k was fitted to data from a field experiment in which carrots were harvested at 14 weekly intervals from a succession of 14 weekly sowings. Use of the allometric equation enabled more than 95 per cent of the variation in the weight of tap roots (Y), to be accounted for by reference to the weight of leaves (W). The residual mean square error of the predicted root weight was less than the within-harvest mean error. The exponent k, representing the ratio of relative growth rates of roots to that of leaves was 1.268 ± 0.019, similar to values calculated from field data from California and central Russia. Large differences in the relative growth rate ratio were found in the germination and flowering phases of growth, when values of k were 0.814 and -0.095 respectively. These differences, together with those found between cultivars, were associated with differing root shapes.