Abstract:Due to the scarcity of water, it is necessary to develop an environmentally friendly method for increasing water productivity and crop production. An experiment was conducted to assess the effects of different magnetic levels (magnetic water level 1 (MWL 1) = 3800 Gauss, magnetic water level 2 (MWL 2) = 5250 Gauss, and magnetic water level 3 (MWL 3) = 6300 Gauss, as well as normal water (NW) as a control) in combination with three soilless culture systems (a nutrient film technique (NFT) hydroponics system, a tower aeroponics system, and a pyramidal aeroponics system. The results showed that the utilization of magnetic water had significant effects on the yield and growth of strawberry plants The tower aeroponic system under MWL 3 produced the highest yield and water productivity, with increases of 80.9% and 89%, respectively, over the control. The tower aeroponic system under MWL 3 produced the highest yield and water productivity, with increases of 80.9% and 89%, respectively, over the control. In addition, as compared to the NW, the NFT system increased yield and water productivity by 71.1% and 79.3%, respectively, whilst the pyramidal system increased yield and water productivity by 66.87% and 82%, respectively. Furthermore, when compared to the control, the combination of the NFT system and magnetic water level 3 (MWL 3) resulted in the most leaves, largest stem diameter, and largest leaf area of the strawberry plants resulted in the most leaves, stem diameter, and leaf area of strawberry plants. In comparison to all other treatments, this combination produced the best fruit quality and yield, as well as its constituents, such as titratable acidity, total soluble solids, and fruit hardness. This study found that combining magnetic therapy with soilless culture techniques resulted in increased yield and water productivity. In addition, water and fertigation solution usage in the NFT, tower, and pyramidal systems dropped by 4.8%, 6%, and 4.8%, respectively. Furthermore, it enhanced plant morphology and plant quality.Keywords: aeroponics; strawberry yield and growth characteristics; magnetic water; water productivity; water consumption
Maintaining a non-pathogenic environment in the root zone is critical for good plant vigor under soilless crops. It is extremely difficult to achieve this and crucial to minimize the population of plant pathogens in the root zone . A common disease in hydroponic solutions is wilt caused by Fusarium spp. and Verticillium spp. Species of Pythium spp. and Phytophthora spp. destroy everything except the main roots. There are no effective fungicides that can be safely used in hydroponics . Only metalaxyl has been shown to be highly effective in controlling Pythium spp. on vegetable crops, but it is not registered for use. In addition to environmental regulations that restrict the discharge of pesticides into the environment, there are no appropriate agents against many diseases, and often disease-causing pathogens develop resistance to pesticides over time .
Other researchers have investigated the environmental impact of three hydroponic tomato production systems using LCA. Two NFT systems and one drip system with granulated rockwool were used for production. All inputs and outputs of each hydroponic system were divided into structural materials, cultivation inputs and waste. Structural materials and wastes accounted for a much smaller share of the environmental impacts. The environmental impact of fertilizers as a result of production was the highest. Water consumption, on the other hand, had a much lower environmental impact in all systems. However, all systems had different water consumption levels, with drip irrigation having the lowest water consumption. The impact of fertilizers could be minimized through a proper irrigation schedule and needs to be studied and improved in more detail as it probably has the most visible environmental impact .
Improved fertilizer management for vegetables is important in view of today's need to reduce production costs, conserve natural resources, and minimize possible negative environmental impacts. These goals can be achieved through optimum management of the fertilizer applied. Understanding the crop nutrient requirements and using soil testing to predict fertilizer needs are keys to fertilizer management efficiency.
Soilless culture systems mainly operate in controlled environmental conditions (greenhouse or plant factory) and increase water use efficiency, especially in closed systems with a recirculating water/nutrient solution that recaptures the drain water for reuse1. The main advantage of soilless cultures is that plants are grown in a controlled environment. Soilless cultivation improves control of the growing medium and avoids problems with irrigation and maintaining proper nutrient concentrations. Hence, good control of the plant growth and better quality crops compared to traditional production in soil.
The inoculation by PGPRs and mycorrhiza may encourage the production of biologically active substances such as phytohormones, amino acids and water-soluble vitamins. Some activating hormones, which play an essential role in plant growth and the bio-fertilization, may increase the contents of IAA (Indole Acetic Acid), Cytokinins and GA3 (Giberallic Acid)25. These phytohormones enable plant cell growth and division and the extension of roots and effect the hormonal balance of plants27. It is reported that the application of bio-fertilizers had stimulating effects on plants by hormones, nitrogen fixation, phosphate solubilization, and siderophore production and helped reduce the use of chemical mineral fertilizers and improved plant growth and productivity26,27.
The mycorrhiza treatment shows the highest amount of manganese and iron in basil, which are higher than the 100% control (Fig. 2). Several studies confirm that the increase in mineral intake is explained by the formation of an extra radical hyphae chain that enlarges the absorptive area of plant roots, which strengthens the efficiency of the intake of manganese and iron by mycorrhiza43,44,45. In contrast, the highest amount of Cu was recorded by using bacteria. The production of siderophore from certain bacteria, like Pseudomonas fluorescens, promotes the accumulation of Cu and Fe due to their ability to regulate the translocation of metals from roots to shoots46. Zinc was the abundant element for micro-algae, even higher than 50% control. According to Zaheer et al.47, the absorption of zinc by the plant enhances the photosynthesis process, ameliorating the yield and the quality of basil.
"Hydroponics is one of the systems in agriculture which reinforce productivity by controlling environmental and growing conditions," the researchers say. "However, the soil has rich amounts of beneficial microorganisms, supporting plant nutrition, producing phytohormones, controlling phytopathogens, and improving soil structure. Soilless culture usually contains no beneficial microorganisms if we do not include them in the system." In this study, they evaluated the effect of three bio-fertilizers, namely bacteria, micro-algae, and mycorrhiza, on basil leaf yield and quality (Ocimum basilicum L.) in a floating culture system.
"It was observed that this bio-fertilizer increased the formation of lateral branches in the basil plant without thickening its stems. In addition, bacteria and mycorrhiza induced the highest percentage of dry matter and total soluble solids", the researchers say. "The effect of bio-fertilizers on basil leaf EC and pH was insignificant for all the treatments at different harvest periods (p < 0.05). Using bio-fertilizers enhanced the intake of nutrients N (nitrogen), P (phosphorus), K (potassium), Ca (calcium), Mg (magnesium), Fe (iron), Mn (manganese), Zn (zinc), and Cu (copper).
"Using bio-fertilizers represents a promising and environmentally friendly approach to increasing crop yields and ameliorating quality and antioxidant compounds with fewer resources. An application of bio-fertilizers in hydroponic cultivation of basil cv. 'Dino' reduced the need for mineral fertilizers. At the same time, bio-fertilizers affected an increased plant yield and improved product quality. Furthermore, the bacteria had a pronounced enhancing effect on the increase of phenol and flavonoids in the leaves of basil plants."
This study aimed to determine how different pollen sources, including self-pollination and cross-pollination, affect the characteristics of strawberry fruit under controlled conditions. In particular, the study tested the effects of pollination on yield, mass, size, shape, colour, sweetness, acidity, firmness, shelf life and mineral nutrient concentrations of strawberry fruit. Furthermore, it assessed the effects of pollination on the number and percentage of fertilized seeds per fruit and established whether these values affected fruit characteristics. Results from the study will provide greater understanding of the effects of pollen transfer on the quality of strawberry fruit.
Data were analysed using IBM SPSS Statistics v. 26 (IBM, Armonk, NY). Yield data was analysed by 1-way analysis of variance (ANOVA). Fruit quality and shelf life data were analysed using generalized linear models (GLMs). Pollination treatment and plant (nested within pollination treatment) were regarded as main effects, and the date of harvest of each fruit was incorporated as a covariate. Due to highly significant effects of date of harvest, a series of GLMs was used to compare two pollination treatments in each model. Holm-Bonferroni corrections were applied to adjust the significance values for multiple models. Linear regressions were also performed to evaluate effects of the number of fertilized seeds, the percentage of fertilized seeds, the number of unfertilized seeds, or the percentage of unfertilized seeds per fruit as the independent variable and fruit quality parameters as the dependent variable. Treatment differences or regressions were regarded as significant at P < 0.05. Means are presented with standard errors. 2b1af7f3a8