Dry matter distribution between shoot and storage root of carrot, parsnip, radish and red beet

Abstract

The relationship between shoot and storage root weights of carrot, parsnip, radish and red beet was examined using plants of different size and age. For both carrot and parsnip plants of the same age there was a linear relationship between the logarithms of shoot and storage root d. wts which was unaffected by plant density. For parsnip the parameters of the regression were unchanged by harvest time, while for carrot the slope of the regression remained constant and the intercept progressively declined with harvest time. These observations are consistent with an hypothesis of assimilate partition based on competition between sinks. For both radish and red beet at very high densities the logarithmic relationship between shoot and storage root weight was curvilinear with significant effects of both harvest time and density. It is suggested that interplant competition may affect the initiation of storage tissue development in both these species. It is concluded that for radish and red beet, even when considering only plants producing normal swollen storage roots, partition of assimilate is affected by factors not incorporated into the above hypothesis. © 1984 Annals of Botany Company.