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Today, the use of light emitting diodes (LEDs) are rapidly increasing in horticulture industry as a result of technological advancements. Lighting systems play an important role in the commercial greenhouse productions. As an artificial source of light, LED lamps can contribute to the better and faster growth of horticulture products such as vegetables grown in greenhouses. In this study, the effects of red and blue light spectrums were implemented and performed as a pot experiment under the cultivation-without-soil condition in greenhouse based on a completely random plan with 3 lighting treatments including natural light (control), 60% red light +40% blue light (60R:40B), and 90% red light +10% blue light (90R:10B), repeated 3 times. The results showed that the application of blue and red lights affected the fresh and dry weights of cress as well as its biomass, demonstrating a considerable increase compared to the plants grown under natural sunlight condition. In this regard, the fresh weight of the plant under the 60R:40B treatment had 57.11% increase compared to the natural light treatment. Compared to the control sample, the dry weight had 26.06% increase under 90R:10B treatment. The highest extent of biomass was observed under the 60R:40B lighting treatment with a value of 1.51 (g per kg dry weight of the plant), which was a 68.87% increase compared to the natural light treatment. Under the 60R:40B treatment, cress had its highest length at 19.76 cm. Under the similar treatment, the cress leaf had a total area of 56.78 cm 2 which was the largest. The stem diameter and the number of leaves under the 60R:40B treatment had their highest values at 3.28 mm and 8.16, respectively. Accordingly, a growing trend was observed with 56.7 and 61.27% increase compared to the control treatment. Furthermore, the biochemical traits of cress, the amount of a, b and total chlorophyll, the amount of anthocyanin and phenolic contents under the application of red and blue light were at their highest values compared to the control treatment. The highest amount of chlorophyll was observed under 60R:40B treatment as 15.09 mg g −1 FW leaf. Moreover, the phenolic contents and the amount of anthocyanin were of significant difference at 1% level of likelihood compared to the control treatment. Therefore, the vegetative growth of cress was substantially affected by red and blue lights, resulting in the enhancement of the plant's biochemical features compared to control condition via adjusting the lighting quality and impacts of each red and blue light spectrum on their specific receptors. As a result, the presence of both lighting spectrums is essential for expanding and increasing the quality of the plant. At the large scale, this technology is capable of improving the commercial greenhouse production performance while helping farmers achieve maximum products. This particular combination of lights is one of the beneficial features of LED lighting systems intended for different types ...

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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 open field. Treatments consisted of four levels of compost (0, 5, 10 and 15 ton ha -1 ).The experiment was designed in randomized block design with three replications. Compost treatments positively affected fruit antioxidant compounds of pepper (antioxidant activity, total phenolic and carbohydrate content).But, no significant difference was found in total flavonoid content between compost and control treatments. The highest antioxidant activity and carbohydrate content were obtained in plants treated with10 ton ha -1 of compost. Fruit quality factors (pH, total soluble solids, titratable acidity, ascorbic acid and fruit firmness) were influenced by compost treatments. Total soluble solids, and fruit firmness significantly increased in response to compost treatments and the highest values were obtained from the most level of compost treatment (15 t ha -1 ). Thus, these results showed that compost has strong impact on fruit quality and antioxidant compounds of pepper plants under field conditions.

Medicinal pumpkin (Cucurbita pepo convar. pepo var. styriaca) is an important annual plant that belongs to Cucurbitaceae family. The seeds of this plant, which are used to cure the prostatic hypertrophy and urinary tract irritation, contain fatty oil, β-sitosterol and E-vitamin as active substances and Zn as important nutritional element The effect of nitrogen levels on leaf N and chlorophyll (a, b, and total) content, seed yield, oil yield, and Zn content was examined. The nitrogen treatments were at five levels (0, 75, 150, 225, and 300 Kgha-1) that were applied at three different stages of the plant growth (seed sowing time, four leaf stage and flowering). The results indicated that nitrogen fertilization increased the amount of chlorophylls and N content of the leaves compared to the control. The highest rate of chlorophylls and N content of the leaves was obtained when nitrogen applied at 300 and 225 kgha-1 level, respectively. Also the highest seed dry weight and oil seed content were obtained at 75 kgha-1 of nitrogen. The highest β-sitosterol level showed at 150 kgha-1 of nitrogen. Zn content of the seeds decreased with nitrogen increasing, but the control indicated highest amount of the Zn.

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. Nitrogen was applied in four rates (0, 50, 100 and 150 Kg/ha). Average plant height, lateral stem number, leaf chlorophyll content, flower number, fruit weight and plant yield were determined , Increasing rates of Nitrogen significantly affected plant vegetative growth (plant height, lateral stem number, and leaf chlorophyll content).The highest lateral stem number and leaf chlorophyll content were obtained in plants receiving 150 Kg N ha-1. Nitrogen fertilizer affected flower number and the days to first flowering. Nitrogen application decreased the days to first flowering and treated plants flowered early than control. It was observed that fertilization with 100 Kg N ha-1 resulted in the highest average fruit weight and fruit yield. Our results showed that nitrogen fertilization has strongly influenced vegetative and reproductive growth of eggplant plants grown under field conditions.