THE INFLUENCE OF VARIETY AND GROWTH-CONDITIONS ON THE NUTRITIVE-VALUE OF CARROTS

Three carrot varieties were cultivated under different growth conditions repeated over 2 years. A total of 35 samples, differing in variety (early, mid and late season type), total nitrogen supply (40-60 kg N per ha, 90-120 kg N per ha, 180-190 kg N per ha), time of harvest (early, mid and late) and cultivation year (1990 and 1991), were evaluated. The nutritive value of each of the 35 carrot samples was determined in trials with rats. Of the chemical components analysed, protein content exhibited the largest variation (46-101 g kg(-1) DM). The late season variety had the highest protein content and the early season variety the lowest. The protein content increased with nitrogen fertilisation. The protein digestibility increased together with the protein content, probably due to a larger proportion of the protein being deposited as storage protein. The protein increment was accompanied by a significant drop in essential amino acids (g per 16 g N). The energy content was low (165-173 MJ kg(-1) DM). However, the energy digestibility was high (76.2-88.8%) due to a large proportion of soluble fibre in the dietary fibre fraction. The content of Cd and Pb was below what is considered as acceptable levels.