Can just one-second measurement of chlorophyll a fluorescence be used to predict sulphur deficiency in radish (Raphanus sativus L. sativus) plants?

•Changes in photosynthetic apparatus become earlier than S deficiency visible effects.•Sulphur deficiency decreased chlorophyll content and grana size.•Sulphur deficiency decreased the electron transport rate.•Some sensitive parameters of OJIP test were altered.•Stress can be detected by Principal Component Analysis of numerous JIP parameters.