Application of melatonin and Fe-DTPA on cucumber under modelled iron deficiency conditions
Type:
Article
Pages:
from 591
to 596
Status:
In work
Received:
15.08.2026
Accepted:
15.08.2026
Published:
15.08.2026
Language:
Russian
Keywords:
melatonin, Fe-DTPA, iron deficiency, cucumber, stress
Abstract:
This study was conducted to investigate the effects of the combined application of melatonin and iron chelate (Fe-DTPA) on the growth, photosynthetic activity, and physiological-biochemical stress indicators of cucumber under artificially induced iron deficiency. The effect of combining melatonin with micronutrient fertilizers had not been previously studied. To achieve this goal, a model vegetation experiment was established using cucumber (Cucumis sativus L.) grown in a sandy substrate and supplied with a nutrient solution of specified composition. During the experiment, seeds were soaked and foliar treatments of vegetating plants were performed twice at the full expansion stage of the first and third leaves using melatonin solutions (1 mg/L for seeds and 25 mg/L for foliar application) and Fe-DTPA (1 g/L). The effects of the treatments were evaluated by measuring biometric parameters, chlorophyll and carotenoid content, PAM fluorometric analysis of photosystem II activity, and stress indicators such as lipid peroxidation, catalase activity, water-soluble carbohydrate content, and membrane stability. It was found that the combined application of melatonin and Fe-DTPA exerted a synergistic effect on cucumber growth. This treatment led to an increase in leaf area (+3.1% compared to control), number of leaves (+6.4%), dry weight of leaves (+3.8%), total stem length (+12.6%), and dry stem weight (+2.4%). Treated plants also showed a higher proportion of the stable fraction of all photosynthetic pigments (over 99% compared to 84.0–88.8% in the control) and significant accumulation of water-soluble carbohydrates in leaf tissues (+34.8%). In terms of photosystem II performance and other physiological-biochemical stress parameters, the effect of the combined application of melatonin and Fe-DTPA did not exceed that of their individual applications.
This study was conducted to investigate the effects of the combined application of melatonin and iron chelate (Fe-DTPA) on the growth, photosynthetic activity, and physiological-biochemical stress indicators of cucumber under artificially induced iron deficiency. The effect of combining melatonin with micronutrient fertilizers had not been previously studied. To achieve this goal, a model vegetation experiment was established using cucumber (Cucumis sativus L.) grown in a sandy substrate and supplied with a nutrient solution of specified composition. During the experiment, seeds were soaked and foliar treatments of vegetating plants were performed twice at the full expansion stage of the first and third leaves using melatonin solutions (1 mg/L for seeds and 25 mg/L for foliar application) and Fe-DTPA (1 g/L). The effects of the treatments were evaluated by measuring biometric parameters, chlorophyll and carotenoid content, PAM fluorometric analysis of photosystem II activity, and stress indicators such as lipid peroxidation, catalase activity, water-soluble carbohydrate content, and membrane stability. It was found that the combined application of melatonin and Fe-DTPA exerted a synergistic effect on cucumber growth. This treatment led to an increase in leaf area (+3.1% compared to control), number of leaves (+6.4%), dry weight of leaves (+3.8%), total stem length (+12.6%), and dry stem weight (+2.4%). Treated plants also showed a higher proportion of the stable fraction of all photosynthetic pigments (over 99% compared to 84.0–88.8% in the control) and significant accumulation of water-soluble carbohydrates in leaf tissues (+34.8%). In terms of photosystem II performance and other physiological-biochemical stress parameters, the effect of the combined application of melatonin and Fe-DTPA did not exceed that of their individual applications.
Keywords:
melatonin, Fe-DTPA, iron deficiency, cucumber, stress
melatonin, Fe-DTPA, iron deficiency, cucumber, stress
