Document Type : Research Article
Authors
Department of Horticulture and Landscape Architecture, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran
Abstract
Introduction
As an artificial light source, LED bulbs can help to grow better and faster greenhouse products. Meanwhile, blue and red light are important for plant growth. The quality of light in terms of color and wavelength can affect the morphological structure of the plants. Therefore, the use of additional lights in winter, when light exposure is less than normal, can improve plant growth and flowering. It is also advisable to change the quality of light by using artificial light sources in controlled environments such as greenhouses in order to change the quantity and quality of agricultural products, especially fruits.
Materials and Methods
In this research, the effect of complementary light and nutrition (commercial Calfomyth solution containing high calcium phosphorus and calcium elements along with micronutrient elements) as a pot experiment under non-soil culture conditions in the greenhouse, in the form of split-based plots experiment A completely randomized design with 3 light treatments including: natural light (control), 60% red light + 40% light blue and 90% red light + 10% blue light, and 2 nutritional treatments including: non-spraying with commercial fertilizer, Calfomyth and spraying A concentration of 2,000 in 3 replicates was established and implemented. The traits that were studied in this experiment are: 1- leaf number (count of leaves), 2- plant height by meter, with accuracy 0.01 m, 3- diameter with caliber with accuracy 0.01 mm, 4- Number of flowers (counting), 5- Time of flowering until the product reaches (counting the number of days), 6- Performance: Whole and red ripe fruits were planted and weighed separately from the total fruit weight Per plant was obtained in grams per plant. Statistical analysis was performed using JMP8 software and comparison of means was done using LSD test at 1% and 5% probability levels.
Results and Discussion
The results showed that the application of additional light on fruit yield, stem diameter and plant height, yield time and leaf number (p≤0.05) were significant. Spraying with Calfomyth could have a significant effect on stem diameter and number of leaves. In the traits such as fruit yield, number of flowers and leaves, the interaction effect of feeding and supplementary light was also significant. The highest elevation was observed for 60% red + 40% blue (25.38 m) and the lowest for light control treatment (20.72 m). Also, the shortest arrival time was 90% red + 10% water treatment in 29 days and the maximum time to reach the product was 45 days. The highest number of leaves belonged to 60% red + 40% blue treatment, as well as spraying with Calfomyth (118), the highest number of flowers (50) was related to 90% red + 10% blue and Calfomyth treatment, and the smallest number ( 15) was related to control treatment. Also, the highest yield (3553 g of fruit per plant) was obtained in Calfomyth treatment with 90% red + 10% blue treatment and the lowest yield (434 g fruit per plant) The control was light and non-foliar treatment. Although light is an important source of photosynthesis, photosynthesis can also be related to a series of optical regulators and optical sensors. Blue and red light cause different optical sensors and expression of genes, each of which can have a positive or negative effect on plant growth and development. Therefore, it can be concluded that the presence of both wavelengths (blue and red) is necessary for conducting, and for this reason, more research is now focused on achieving an appropriate optical composition.
Conclusion
In this research, all of the morphological traits examined in the tomato (Lycopersicon esculentum) plant were subjected to additional exposure by LED bulbs, each of which had a special effect on their receptors in the plant. Maximize growth and yield in the plant. As expected, blue light on vegetative traits and red light were more effective on reproductive traits. It can be said that the existence of both wavelengths (blue and red) is essential for the better and complete growth of the plant. In addition to the positive effect of wavelengths, the positive effect of leaf spraying can also be observed, which, along with the neodymium, could improve growth. The results of this study showed that the performance and growth under the cover of LED light (red and blue combination) were superior to natural conditions. Therefore, it could be suggested that the use of these lamps, as well as spraying with Calfomyth commercial fertilizer, could be feasible for better production in controlled conditions (greenhouse). It seems that application of complementary lights with proper nutrition can improve the performance and growth of tomato plants in greenhouse conditions.
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