Effect of cultivar and harvest date on nitrate content of carrot roots

Abstract

SummaryNitrate content is an important quality characteristic of carrots (Daucus carota L.) for the processing industry, so growers strive for the lowest possible values. The objective of this study was to determine whether selection of cultivars or timing of harvest could contribute to producing low nitrate contents in carrots. Field experiments with 24 carrot cultivars were conducted in three years on sandy soil. Rank order correlation and regression analysis showed that cultivar and harvest date may have significant effects on nitrate content in single experiments, but these effects could not be reproduced in another year. Our results suggest that these effects are small when compared with effects of other factors (e.g. irradiance, temperature) that are not usually controlled in field experiments. In contrast to the control of nitrogen supply, selection of cultivars and harvest dates cannot be recommended as a means of reducing the risk of high nitrate content in carrot production.