The tomato crop is very sensitive to stress conditions. A water deficit is defined as when precipitation is less than the evapotranspiration (ETc) of the crop in a given period, and in this scenario of climate change, it is identified as responsible for global productivity losses. The use of potential technologies for better irrigation management, such as electromagnetically treated water, remains controversial. Thus, the objective of the present work was to investigate the effects of very low-frequency electromagnetic resonance field treatment on water for tomato crops submitted to different irrigation rates. For this, an experiment was carried out under controlled conditions with different types of water: electromagnetically treated water (WTVLF) and untreated water (UNW), as well as four water replacement rates: 40, 60, 80, and 100% ETc. The electromagnetic treatment of the water was carried out using the commercial equipment AQUA4D^®. The experiment was carried out in pots with five replications per treatment. Lower activity of SOD, POD, CAT, and APX enzymes was observed in plants irrigated with water treated with very low-frequency electromagnetic resonance fields (WTVLF), indicating less oxidative stress caused by water deficit. Water deficit reduced chlorophyll content, but the effects were less harmful with WTVLF water. The water deficit resulted in less accumulation of dry matter and less productivity in a linear relationship. However, plants irrigated with WTVLF showed increments of about 20% in dry matter accumulation and 20% in fruit production concerning plants irrigated with untreated water, independent of the irrigation rates. We can conclude that irrigation with WTVLF can be a solution to reduce the damage caused by water deficits and increase the productivity of tomato crops.

There are few studies about the influence of fruit maturation and post-harvest resting on seed composition, which can be necessary for seedling development and future establishment. Thus, the objective of this study was to evaluate the effect of maturation and post-harvest resting of fruits on the macronutrient and protein content of sweet pepper seeds. The experimental design was a randomized block, with eight treatments, in a 4 × 2 factorial arrangement. The first factor was fruit maturation stages (35, 50, 65 and 80 days after anthesis), and the second, with and without post-harvest resting of the fruits for 7 days. The characteristics evaluated in seeds were the dry weight of one thousand seeds, macronutrient content, and content of albumin, globulin, prolamin and glutelin proteins. There were reductions in K, Ca and Mg content, and an increase in seed content of albumin, globulin and prolamins as a function of the fruit maturation stage. Post-harvest resting of the fruits provided higher Ca content and protein albumin in seeds. The decreasing order of macronutrients and protein content in seeds, independent of fruit maturation and resting stage of the fruits, was N > K > P > Mg > S > Ca, and albumin > globulin ≈ glutelin > prolamine, respectively.

It is known that poorly performed fertigation directly impacts on tomato production and biometric components. In addition, consumers are also affected by interrelated characteristics that interfere with the acceptability of the fruit, such as the physicochemical parameters and nutrients in the fruit. Thus, eco-friendly technologies, such as irrigation with ultra-low frequency electromagnetic treated-water, which attenuates the inadequate management of fertigation, are essential to improve marketable fruit yields. Thus, the objective of the present work was to investigate the impact of treated water with very low-frequency electromagnetic resonance fields in physical, chemical and nutritional parameters at different nutrient solution strengths in tomato fruits. In this study, experiments were carried out in randomized blocks and five doses of fertigation were used (1.5; 2.5; 4.0; 5.5; and 7.0 dS m⁻¹), employing two types of water: electromagnetically treated and untreated. It can be seen that the fertigation affected some parameters, mainly the number of fruits with blossom-end rot, fruit size, and weight. Variance analysis (ANOVA) was performed with the subsequent use of the Tukey test. In all statistical tests, a confidence level of 95% was considered. The soluble solids content increased by 28% as a function of the fertigation doses. The electromagnetically treated water reduced the number of fruits with blossom-end rot by 35% (p < 0.05). Overall, electromagnetic water improved the physicochemical quality parameters and the nutritional status of tomato fruits. Thus, this study demonstrated that green technology could leverage tomato fruit production and quality.

The common bean (Phaseolus vulgaris L.) is a global staple, but to guarantee its provision, the crop water supply must be adequate, and bioinput application can benefit plants under drought. The objective was to evaluate the common bean’s response to bioinput application when it was cropped in soils with different water holding capacities submitted to a drought period. The greenhouse experiment used sandy loam and clayey soils. Seeds were sown, and 10 days after emergence (DAE), the treatments were applied: (i) no bioinput application or (ii) bioinput application (Priestia aryabhattai, re-applied at 46 DAE). The first plant growth evaluation was performed at 40 DAE. The irrigation maintained the crops’ needs until the beginning of flowering for all the treatments, when the irrigation was differentiated (for 10 days): (i) maintenance of irrigation or (ii) a drought period. A biochemical analysis was performed of superoxide dismutase activity [SOD], hydrogen peroxide [H₂O₂], peroxidase activity [POD], and malonaldehyde [MDA] production at 52 DAE. At 57 DAE, the second plant growth evaluation was performed, and the irrigation differentiation ended. Grain harvest followed physiological maturation. Priestia aryabhattai mitigated the drought stress in the common bean cropped in sandy soil by reducing the SOD, H₂O₂, and MDA production in comparison to no bioinput application. When it was cultivated in the clayey soil, the water availability was maintained for longer, reducing the plant’s dependency on bacteria for stress mitigation.

Management of irrigation and fertilization in greenhouses, if not done correctly, can cause soil salinization. The use of water treated with very low-frequency electromagnetic resonance fields (WVLF) can reduce salinization effects on the photosynthetic and biometric systems. Thus, the purpose of the research to evaluate the metabolism of photosynthesis and the impact of WVLF on the cultivation of tomato crops subjected to different levels of fertigation. For this, the gas exchange parameters were evaluated, as well as chlorophyll a fluorescence, sugar contents, sucrose, chlorophylls, and phaeophytins and fruit production. The gas exchange parameters had greater activity when subjected to irrigation with electromagnetic water, consequently the production of sugar and sucrose increased. Photosynthetic System II showed less salinity effect, being favored by very low-frequency electromagnetic resonance fields. The production increased by 20% for the dose of 2.5 d·Sm⁻¹ of WVLF reducing the effects caused by higher doses. Hence, the induction of water by electromagnetic fields can provide less damage to the photosynthetic system and to the cultivation of the tomato crop when subjected to saline stress and, consequently, favor the production of fruits by this crop under such conditions.

Este trabalho teve como objetivo realizar um estudo de viabilidade econômica para implantação de um biodigestor anaeróbico analisando os cálculos do Tempo de retorno (payback), Valor presente líquido (VPL), Taxa interno de retorno (TIR) obtidos de uma planilha de Excel. A pesquisa foi de viés bibliográfico com estudo empírico por permitir incluir análises secundárias não consideradas em relatos anteriores. Os biodigestores anaeróbicos são tecnologias que podem auxiliar o produtor rural e o meio ambiente com a produção de biofertilizante para agricultura e biogás para aquecimento ou produção de energia elétrica. Para fazer cálculos de viabilidade econômica usou-se o investimento de R$ 44.500,00 feito pela Unifenas para montar o projeto do biodigestor. As receitas consideradas na análise financeira foram com base na saving de energia elétrica de R$ 2.225,00 por mês e a venda de biofertilizante, totalizando uma receita mensal de R$ 2.975,00. Após a análise de viabilidade econômica, fez-se uma comparação com um investimento em Letra de crédito Imobiliário – LCI para verificar qual investimento é mais viável. Assim, este trabalho mostrou que os dois investimentos são viáveis, porém, a implantação de um biodigestor se mostra melhor porque auxilia a questão ambiental.