Growth and chemical composition of carrots as influenced by the time of sowing and harvest

Abstract

SummaryThe effects of the time of sowing on growth and chemical composition of carrots grown from May to November were studied during 3 years.Delaying sowing for 1 or 2 months after the beginning of May resulted in a reduction in the growth of both roots and foliage and gave roots with lower dry-matter content and glucose/fructose ratio but higher amounts of hexoses, total nitrogen and amino nitrogen in root dry matter. Sowing date had no influence on the concentration of sucrose, phosphorus, potassium, calcium and magnesium in root dry matter up to 137 days from sowing. Carotene decreased only after the last sowing. Sucrose concentration of the roots increased throughout the periods studied irrespective of the time of sowing. The longer the growing period the higher was the sucrose concentration. The concentration of hexoses decreased from the first harvest at 70 days to reach a constant level at about 130 days from sowing.The results did not indicate the presence of a well-defined stage of biochemical maturity in the autumn when carrot roots are expected as most suitable for harvest and subsequent long-term storage.