Nowadays the importance of selenium for human health is widely known, but most of the plants are poor in terms of selenium storage and accumulation because of the low selenium mineralization potential of the soil. For this purpose, foliar application of different sodium selenate concentrations (0, 5, 10, 15, 20 mg/L) was used to treat the cauliflower cultivars “Clapton” and “Graffiti”. Higher yields and other related vegetative attributes were improved at 10 and 15 mg/L sodium selenate application. At a concentration of 10 mg/L sodium selenate, photosynthetic pigments, total phenolic compounds and antioxidant capacity were enhanced in both cultivars, but the “Graffiti” cultivar responded stronger than the “Clapton” cultivar. The glucosinolates were accumulated in response to selenium fortification and the highest amounts were found in the “Graffiti” cultivar at 10 mg/L. Selenium accumulated concentration-dependently and rose with higher fertilization levels. In general, foliar application of selenium at 10 mg/L led to an accumulation of secondary metabolites and also positively affected the growth and yield of florets.
Global climate change minimizes fresh water resources used in agriculture worldwide. It causes drought stress, which has adverse effects on plants. To ensure food security, crops and vegetables capable of tolerating shortages of water over the growth period are needed. This study aimed to elucidate the morphological and biochemical responses of three colored cauliflower (Brassica oleracea var. botrytis) cultivars (Clapton, Trevi, and Di Sicilia Violetto) and one broccoli cultivar (Brassica oleracea var. italica var. Magic) to different irrigation treatments (85–100%, 65–80%, 45–60%, and 25–40% field capacity). Assessment of growth parameters revealed no significant difference among all the treatments for root fresh weight, leaf area, and floret size. Major water shortages reduced the floret and stem fresh weight of the Clapton cultivar. Additionally, under severe drought stress, only the Di Sicilia Violetto cultivar had a decrease in plant height, but no impact on the number of leaves was observed. The measurement of pigment contents in the leaves showed no significant difference in carotenoids in all the cultivars; just the chlorophyll contents decreased with moderate stress in the Di Sicilia Violetto cultivar. This research demonstrates that cauliflower and broccoli are likely drought-tolerant vegetables and common irrigation regimes may be reviewed.