The present study aimed to investigate the effect of selenium on flowering indices, sex determination of flowers, and yield of cucumber plant under heavy metal stress conditions. Treatments consisted of selenium (0, 4, 6, 8 mgL⁻¹) and heavy metals of cadmium (0, 20, 25 µM) and lead (0, 60, 100 µM), which were applied in three stages during the experiment period. The results of this study showed that the stress of heavy metals with a negative effect on flowering indices resulted in delayed flowering and changing flower’s sex toward male flowers. Furthermore, delayed fruiting and significant decreases in fruit growth indices and total yield was observed in plants treated with cadmium and lead. Adding selenium to the culture medium resulted in accelerated flowering (reducing the time and number of nodes needed until the first flower emerges), the emergence of more male flowers, increased the ratio of the number of female flowers to male flowers in plants under stress, and the highest effect of this element was observed at the concentration 6 mg/L. Based on this results, the application of 4and 6mg/L selenium in stress and non-stress conditions enhanced fruiting (a significant reduction in the time required from cultivation to fertilize the first flower and the formation of fruit in lower nodes) and significantly increased the number of fruits, fruit length and diameter, single fruit weight and total yield, and the greatest effect of this element was observed in 6 mg/L concentration. The results of this study showed that selenium has a positive effect on control of stress conditions and improvement of flowering indices and total yield in cucumber plant under the stress of heavy elements of lead and cadmium.

The present research was carried out to evaluate response of paprika pepper (Capsicum annum L.) to nitrogen (N) fertilizer under field conditions. Nitrogen was supplied in four levels (0, 50, 100 and 150 kg ha⁻¹). Plant height, leaf chlorophyll content, fruit weight, yield, seed number, 1000 seed weight and vitamin C were assessed at immature and mature stages. The results showed that plant height, lateral stem length and leaf chlorophyll content were influenced by N fertilizer. Data indicated that fertilization with 50 g N ha⁻¹ resulted to the best yield and quality components at ripening stage. Although, there was no significant difference in vitamin C content among treated plants with different nitrogen levels at mature stage, but significant differences were shown between treated plants and control. Thus, these results showed that fertilization with 50 kg N ha⁻¹ had strong impact on vegetative and reproductive growth of paprika pepper under field conditions.

The present study was carried out to evaluate the effect of nitrogen fertilizer on growth and yield of eggplant (Solanum melongena L.) under field conditions. ...

The effect of humic acid (HA) on antioxidant compounds and fruit quality of hot pepper (Capsicum annum var. Red chili) was determined in an open-field study. Pepper plants were treated with HA (0, 25, 100, 175, and 250 mg.kg⁻¹). HA treatments affected antioxidants in the fruits (antioxidant activity, total flavonoid, capsaicin, lycopene, and β-carotene). There was no difference in total phenolic and carbohydrate between HA and control treatments. It was observed that HA applied at 100 mg kg⁻¹ resulted in the highest capsaicin and lycopene contents, and the lowest values were observed in control group. Total soluble solids and titratable acidity increased in response to HA treatments, and the highest values were obtained from the highest HA treatment (250 mg kg⁻¹).

In order to determine the effect of compost (CO) on antioxidant compounds and fruit quality of sweet pepper (Capsicum annum L.), an experiment was conducted in...

Healing and acclimatization are critical in vegetable grafting under controlled environments. Here, we investigated the impacts of LED light qualities on the morphological traits and photosynthetic performance of grafted tomato seedlings. Seeds of the tomatoes “DRW 7806 F1” and “Maxifort” (Solanum lycopersicum × Solanum habrochaites) used as scion and rootstock were planted in 104-cell plug trays into a mixture of cocopeat and perlite (volume ratio: 3 to 1). Survival ratio, above- and underground growth, photosynthetic performance, soluble carbohydrate content, pigmentation, and antioxidant enzymes activity were evaluated following 20 days of exposure to different light qualities, including white (35% B, 49% intermediate spectra, 16% R) light as control, blue, red, and a combination of red (68%) and blue with the same light intensity of 75 ± 5 µmol m⁻² s⁻¹. The lowest scion diameter, leaf area, root and shoot dry weight, SPAD value, and the highest scion length and amount of soluble carbohydrate were detected in R-exposed seedlings. Moreover, R-exposed seedlings showed leaf epinasty and reduced photosynthetic performance. On the other hand, RB-exposed seedlings showed the highest leaf area, shoot and root dry weight, plant fresh and dry weight, scion stem diameter and photosystem II efficiency. In addition, superoxide dismutase activity was increased in R-exposed seedlings, while guaiacol peroxidase activity was enhanced in seedlings grown in RB. In conclusion, a combination of R and B is suggested as the suitable light spectrum to promote plant growth and photosynthetic performance in grafted tomato seedlings.