Evaluation of pedoclimatic factors and cultural practices effects on carotenoid and sugar content in carrot root

Abstract

Sugars and carotenoids are recognized as key quality compounds in vegetables due to their sensory and nutritional attributes. Ensuring a guaranteed content for these compounds in carrot crop is a major challenge for producers and breeders. Widely involved in plant acclimation mechanisms, the environment significantly influences their content. A multi-environment trial over two years was used in this study to identify the environmental determinism of carotenoid and sugar accumulation. After a fine characterization of cropping places in dissecting climatic variables, pedological conditions and cultural practices, PLSr models were used for predictive purposes to determine and prioritise pedoclimatic factors and cultural practices involvement. Interestingly, distinctive patterns are observed between sugars and carotenoids. Pedoclimatic factors and cultural practices effects are similar regardless studied carotenoid, with a differential effect in accumulation according to α-branch and β-branch carotenoids. For sugar metabolism, a reverse effect of leading factors is observed depending on sugars class. Our study brings to light the overall limiting effect of some climatic factors as time exposure to low temperature or atmospheric humidity. In contrast, pedological factors were shown to enhance sugar and carotenoid content in carrot, mainly phosphorus, potassium, iron and boron. This study provides useful information for carrot producers to adapt their cultural practice depending on crop place to reach a guaranteed quality in crops. Moreover, our work paves the way for a better understanding of the mechanisms underlying the major pedoclimatic factors and cultural practices effects on the accumulation of key compounds.