Chemical composition of field grown radish (Raphanus sativus L. var. sativus) as influenced by season and moderately reduced water supply

Seasonal variations in water availability as increasingly provoked by climate change pose severe challenges for vegetable production, particularly for crops requiring reliable and high water supply for achieving satisfactory quality. In contrast to most previous studies applying severe water deficits, we examined the effects of moderate water deficits on the chemical composition of red radish tubers during three consecutive years with variable climatic conditions. Radish were cultivated in open field, applying two different water supply treatments and following a randomized block design comprising four sets of six plots each. The resulting water reductions of 3-20% led to a significant increase of dry matter-based myo-inositol levels, whereas those of selected minerals and trace elements, phenolics and glucosinolates decreased. Anthocyanin levels remained unchanged. Fresh-matter related levels of most analytes increased upon reduced water treatments due to higher dry matter contents. While pigment levels in radish remained unchanged, mild water deficit affected other quality-related parameters such as pungency-related glucosinolates.