CARACTERIZAÇÃO FÍSICO-QUÍMICA DE SUBSTRATO DE FIBRA DE CASCA DE COCO APÓS O CULTIVO HIDROPÔNICO DE PIMENTÃO COM ÁGUA DE REÚSO E DIFERENTES LÂMINAS DE SOLUÇÃO NUTRITIVA

CARACTERIZAÇÃO FÍSICO-QUÍMICA DE SUBSTRATO DE FIBRA DE CASCA DE COCO APÓS O CULTIVO HIDROPÔNICO DE PIMENTÃO COM ÁGUA DE REÚSO E DIFERENTES LÂMINAS DE SOLUÇÃO NUTRITIVA1 RENATA DA SILVA CUBA DE CARVALHO2; MARA RÚBIA MENDES DE MELO3; fRANCIELLY GUIEIRO GOMES DE SOUSA4; luís roberto almeida gabriel filho5; antonio evaldo klar6 E hélio grassi filho7 1Trabalho originado da tese de doutorado do primeiro autor intitulada: “Cultivo de pimentão em sistema hidropônico com água de reúso em diferentes níveis de disponibilidade de água no substrato”. 2Doutora, Programa de Pós-graduação em Agronomia – Irrigação e Drenagem, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista (UNESP), Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu-SP, Brasil, [email protected]. 3 Doutoranda, Programa de Pós- graduação em Agronomia, Departamento de Produção e Melhoramento Vegetal. Faculdade de Ciências Agronômica, Universidade Estadual Paulista (UNESP), Rua José Barbosa de Barros, 1780. CEP: 18.610-307, Botucatu-SP - Brasil. E-mail: [email protected]. 4Doutora, Programa de Pós- graduação em Agronomia – Irrigação e Drenagem, Faculdade de Ciências Agronômica, Universidade Estadual Paulista (UNESP), Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu-SP, [email protected]. 5 Professor Associado do Departamento de Gestão, Desenvolvimento e Tecnologia da Faculdade de Ciências e Engenharia, Universidade Estadual Paulista (UNESP), Avenida Domingos da Costa Lopes,780, Jardim Itaipu, 17602-496, Tupã-SP, Brasil, [email protected]. 6 Professor Emérito do Departamento de Engenharia Rural da Faculdade de Ciências Agronômicas, Universidade Estadual Paulista (UNESP), Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu-SP, Brasil. E-mail: [email protected]. 7 Professor Titular do Departamento de Solos e Recursos Ambientais da Faculdade de Ciências Agronômicas, Universidade Estadual Paulista (UNESP), Avenida Universitária, 3780, CEP 18610-034, Altos do Paraíso, Botucatu-SP, Brasil, [email protected]. 1 RESUMO Este trabalho objetivou caracterizar a partir de análises físicas e químicas, o substrato de fibra de casca de coco antes e após o seu uso com a cultura do pimentão, cultivada em vasos com solução nutritiva preparada com água de reúso e água potável e diferentes lâminas de reposição dessa solução (100, 75 e 50% da evapotranspiração da cultura). O cultivo foi realizado em ambiente protegido ao longo de 175 dias, em vasos com capacidade volumétrica de 15 L, preenchidos com fibra de casca de coco. A cada 30 dias mediu-se o pH e a condutividade elétrica do substrato em laboratório. Após a colheita das plantas, foram coletadas amostras do substrato, com as quais avaliaram-se as características químicas e físicas: condutividade elétrica, pH, teores de NH4+, NO3-, P, K, Ca, Mg, S, Cl, B, Fe, Mn, Cu, Zn, capacidade de troca catiônica (CTC), capacidade de retenção de água (10kPA) e densidade volumétrica seca. A reposição de solução nutritiva no substrato através da evapotranspiração da cultura proporcionou aumento dos teores de nutrientes, condutividade elétrica, CTC do substrato e densidade. Os maiores valores desses parâmetros foram verificados para os tratamentos cultivados com solução nutritiva preparada com água de reúso. Palavras chave: salinização, nutrientes, água residuária, hidroponia, efluente. CARVALHO, R. S. C.; MELO, M. R. M.; GOMES, F. G.; GABRIEL FILHO, L. R. A.; KLAR, A. E.; GRASSI FILHO, H. PHYSICAL AND CHEMICAL CHARACTERIZATION OF IN COCONUT HUSK FIBER SUBSTRATE AFTER THE CULTIVATION OF PEPPER IN A HYDROPONIC SYSTEM WITH WATER REUSE AND DIFFERENT DEPHTS OF NUTRIENT SOLUTION 2 ABSTRACT This work aimed to characterize the physical and chemical characteristics of the coconut husk fiber substrate before and after its use with the pepper crop, cultivated in pots with a nutritive solution prepared with reuse and drinking water and different depths of this solution replenishment (100, 75 and 50% of crop evapotranspiration). Cultivation was conducted in pots greenhouse with a volumetric capacity of 15 L, filled with coconut husk fiber. The plants were grown for 175 days and every 30 days, the pH and electrical conductivity of the substrate were measured in the laboratory. After the plants were harvested, samples of the substrate were collected and the chemical and physical characteristics were evaluated: electrical conductivity, pH, NH4 +, NO3-, P, K, Ca, Mg, S, Cl, B, Fe, Mn, Cu, Zn, cation exchange capacity (CTC), water retention capacity (10kPA), and dry bulk density. The replacement of the nutrient solution in the substrate through crop evapotranspiration provided an increase in nutrient content, electrical conductivity, CTC of substrate and density. The highest values for theses parameters were verified ​​for the treatments cultivated with nutritive solution prepared with water reuse. Keywords: salinization, nutrients, wastewater, hydroponic, effluent.

Fertigation Temperature Adjustment Enhances the Yield and Quality of Saffron Grown in a Soilless Culture System

Saffron is one of the most appreciated, traditional, and expensive spices in the world. The objective of our study was to evaluate the effect of cooling the nutrient solution on the production, and organoleptic and commercial qualities of saffron grown in soilless culture. The nutrient solution was cooled to 4 to 5 °C whereas the control treatment was the fertigation supplied at ambient temperature. Corms were placed in a controlled cultivation chamber. The number of flowers per corms, and the weight and length of stigmas were measured. The amounts of safranal, crocin, and picrocrocin were analyzed spectrophotometrically according to the International Organization for Standardization [ISO/TS 3632-2 (2011) Normative]. Our results show that cooling of the nutritive solution increased flower production, the commercial phytochemical content, and organoleptic properties.

Biofortification with selenium increases bioactive compounds and antioxidant capacity in tomato fruits

The objective of biofortification is the human consumption of high nutritional quality food, rich in micronutrients. Selenium (Se) is an essential micronutrient in human nutrition, and its essentiality has not been evidenced in plants. However, its application in crops and subsequent consumption can mitigate the deficiency of this micronutrient in the diet of human populations. This work analyzes the capacity of sodium selenite (Na2SeO3) to increase yield, biosynthesis of bioactive compounds and their accumulation in tomato fruits. For this, five treatments were applied via nutrient solution: 0, 2, 4, 6, and 8 mg L-1. At harvest, the nutraceutical quality and the accumulation of Se in fruits were quantified, as well as the productivity of tomato plant. Biofortification was positively affected by the biosynthesis of phytochemical compounds and their concentration in fruit, although tomato yield decreased. The incorporation of Se in nutritive solution is an alternative to increase both the biosynthesis of phytochemical compounds and the concentration of this element in tomato fruits with the possibility of improving public health through its consumption.

Growth and nutrition of Passiflora edulis submitted to saline stress after silicon application

We carried out greenhouse experiment to evaluate the effect of silicon (Si) on growth and mineral nutrition of yellow passion fruit (Passiflora edulis) submitted to saline stress in a nutritive solution. The experiment comprised a completely randomized design in a 5x4 factorial scheme: five NaCl concentrations (0; 7.5; 15; 30 and 60 mmol L-1) and four SiO2 concentrations (0; 0.5; 1.0 and 1.5 mmol L-1) with four replicates. At the end of 35 days, we measured stem diameter, leaves, stem, and roots dry matter, as well as the macronutrient, Na, Cl, and Si leaf accumulation in plants. In most cases, the increase in NaCl supply in a nutritive solution reduced the dry matter of roots, stem, and leaves. The SiO2 supply attenuated the effect on higher tested saline stress (30 and 60 mmol L-1 NaCl) on roots and stem dry matter. The application of 0.5 mmol L-1 of SiO2 reduced the deleterious effect of salinity on all macronutrients absorption in yellow passion fruit cultivated in a nutritive solution.

Plant growth and rhizome shoots of Agave angustifolia in different substrates, with fertigation and benzylaminopurine

The species Agave angustifolia can be propagated asexually with offshoots from rhizomes, bulbils from inflorescence, and through micropropagation to supply the growing demand for quality plant material for new plantations. In this investigation, Agave angustifolia plants of different initial sizes were evaluated for growth and emission of rhizome shoots, after 14 months under different conditions of substrate, fertigation and application of cytokinins. Bulbils were collected from inflorescences of plants at two sites and classified into two size categories: small (≤ 7 cm) and large (> 7 cm). The bulbils were cultured for 14 months in pots with substrates that were mixtures of sand (A), soil (S), and bovine manure (Bm) (%): 1) A + S (0.3: 0.7); 2) A + S + Bm (0.3: 0.525: 0.175); 3) A + S + Bm (0.3: 0.35: 0.35); 4) A + S + Bm (0.3: 0.175: 0.525). The plants in each substrate were separated into groups for application of different types of irrigation: 1) water; 2) 50% Steiner’s nutritive solution, SNS-50%; 3) SNS-50% + 25 mg L-1 of benzylaminopurine. The results show that the emission of rhizome offshoots was affected by the substrate, type of irrigation and provenance of the plants. The plants in substrates 3 and 4 formed 2.2 rhizome offshoots, which was more than plants in the other substrates. The plants irrigated with water, SNS-50%, and SNS-50% + benzylaminopurine formed 1.1, 1.6 and 1.9 rhizome offshoots, respectively.

Effect of the inoculum/substrate ratio on the biochemical methane potential (BMP) of grape marc

The grape industrialization process produces large volumes of solid organic waste, with the grape bagasse being the main waste generated in the winemaking process. Anaerobic digestion can be used to treat and dispose of agro-industrial biomass waste. The objective of this study was to evaluate the effect of the inoculum/substrate ratio on the Biochemical Methane Potential (BMP) of grape marc. The experiment was performed in laboratory scale through a system of reactor bottles in batches, removing a set of triplicate flasks for sampling and analysis every 48 hours, with the test lasting 12 days. The reactors contained residue, inoculum and 20% of nutritive solution, maintaining 20% of headspace. The reactors were incubated in an incubator at a mesophilic temperature (35 ± 2°C) and shaken manually every 24 hours. Three different inoculum/substrate (I/S) ratios of 0.75, 1.5 and 3 were used to evaluate the methane yield, organic removals and at the end of degradation the morphology of the bacterial community was evaluated by means of scanning electron microscopy. The I/S 3 ratio provided the best results for loading anaerobic systems, indicating that grape marc presents potential for biological treatment through anaerobic digestion.

Improvement of the nutraceutical quality and yield of tomato by application of salicylic acid

Tomato fruits are a unique functional food and a natural reservoir of nutrients, antioxidants, vitamins and bioactive compounds that improve nutrition and human health. As an important vegetable throughout the world, tomatoes have attracted the attention of researchers to carry out various strategies to improve the functionality of this food aimed at the prevention of diseases, health and global well-being. An agronomic strategy in this study was to evaluate the influence of the application of "salicylic acid (SA)" on the yield and nutraceutical quality of the tomato crop, produced under hydroponic conditions. A completely randomized experimental design with six repetitions was used. SA at five doses (0.025, 0.05, 0.075, 0.1 and 0.125 mM) and one control were applied every 15 days in the nutritive solution under a hydroponic system on tomato plants. The evaluated variables were yield (total fruit weight per plant), fruit parameters (weight, diameter, firmness, and total soluble solids), percentage of weight loss and nutraceutical quality of tomato. The results obtained indicate that the addition of salicylic acid in nutritive solution increased the yield and biosynthesis of phytochemical compounds in tomato fruits, in relation to the control without application. In conclusion, to obtain a higher nutraceutical quality without affecting the tomato fruit yield, it is recommended to use the average concentration (0.125 mM) of SA.

Behavior of three lettuce cultivars in a hydroponic system

The cultivation of lettuce in a hydroponic system is an alternative to optimize the production. Lettuce is an important food, being one of the most consumed vegetables in Brazil. The objective of this study was to evaluate the agronomic behavior of commercial cultivars of lettuce under a single nutritive solution in a hydroponic system. The experiment was carried out under greenhouse conditions. The experimental design was completely randomized, with five replicates. The treatments were composed of commercial lettuce cultivars (Americana Great Lakes, Rafaela-Americana, and Simpson Black Seed). At the time of harvest, the following parameters were evaluated: number of leaves, length of leaves and roots, fresh mass of shoot and root, and stem diameter. The collected data were submitted to an ANOVA. The cv. Rafaela-Americana presented higher leaf length. The evaluated cultivars did not present significant differences in the number of leaves, aerial green mass, green root mass, root length, and stem diameter. The cultivars showed similar variations in the number of leaves, aerial green mass, green root mass, root length, and stem diameter. The cultivar Rafaela-Americana presented a superior performance in the development of leaf length regarding the other cultivars.

PURPLE CABBAGE MICROGREENS GROWN IN DIFFERENT SUBSTRATES AND NUTRITIVE SOLUTION CONCENTRATIONS

ABSTRACT Microgreens are young plants that are consumed at the seedling stage, which present short production cycle and require little space for growing. The objective of the present study was to evaluate the yield and nutritional quality of purple cabbage (Brassica oleracea var. capitata f. rubra) microgreens grown in different substrates and nutrient concentrations in the nutritive solution, in a recirculating irrigation system. The experiment was conducted in a protected environment at the Faculty of Agronomy (UFRGS), in Porto Alegre, RS, Brazil. A completely randomized design and three replications were used, with a 4×3 factorial arrangement consisted of four commercial substrates (CSC® vermiculite, Beifiur® S10, Carolina Soil® seedling, and Carolina Soil® organic) and three nutrient concentrations in the nutritive solution (0%, 50%, and 100%). A sub-irrigation system was used for the irrigations. The variables evaluate were: shoot fresh matter yield (SFMY), shoot dry matter yield (SDMY), shoot height at harvest (SHH), production cycle (precocity), and total soluble solids (TSS), total chlorophyll, and carotenoid contents. The different substrates had no effect on the SFMY, SDMY, and SHH of the purple cabbage microgreens; the increasing addition of nutrients to the nutritive solution increased the values of these variables. The TSS and total carotenoid contents decreased as the nutrient concentration in the nutritive solution was increased. The responses of total chlorophyll contents to the substrates and the nutrient concentrations in the nutritive solution varied.