ABSTRACT Melon cultivation under saline conditions is a challenge, as the plants can suffer a reduction in fruit production and quality. The aim of this study was to evaluate the production and quality of noble melon fruit fertigated with different saline solutions and K/Ca ratios. The experimental design was of randomised blocks, with treatments arranged in a 3 x 6 factorial scheme, using three melon cultivars (Bazuca, McLaren, County) fertigated with six nutrient solutions [S1 - standard nutrient solution (SNS); S2 - SNS + NaCl (5.0 dS m-1); S3 - S2 enriched with K (50%); S4 - S2 enriched with K (100%); S5 - S2 enriched with Ca (50%); S6 - S2 enriched with Ca (100%)]. At the end of each cultivar cycle, the fruit was harvested and assessed for the following parameters: fresh fruit weight, fruit diameter, internal cavity, pulp thickness, pulp firmness, soluble solids content, titratable acidity, soluble solids/titratable acidity ratio, and vitamin C. Salt stress impaired the physical characteristics of the fruit of the three noble melon cultivars. The nutrient solution enriched with 50% K (S3) did not reduce the effect of salt stress on fresh weight or fruit size in the melon, but afforded an increase in fruit quality.

ABSTRACT. Since the composition of honey varies with the species of bee as well as flowering and geographical aspects, this study aimed to evaluate the physicochemical and bioactive properties of Apisand stingless bees’honey from the Brazilian Caatinga. Samples of different species of Apis mellifera L.Meliponini (Melipona subnitida, Frieseomellita varia, Melipona mandacaia, Plebeia sp.) and Apis mellifera L.werecollected from honey producersin the state of Rio Grande do Norte. Honey from A. mellifera and stingless bees showed physicochemical differences in some parameters, especially in moisture, free acidity, HMF, water activity, sugars and electric conductivity. There were no differences in color between honeys from A. mellifera and stingless bees. Honeys fromPlebeia sp., F. varia and A. mellifera showed higher antioxidant capacity followed by honeys fromM. mandacaia and M. subnitida. Flavonoids had little influence on the differentiation of antioxidant activities of stingless bees, while the opposite occurred with the phenolic content, where honeys with the highest levels of phenolic also showed higher antioxidant capacity. ABSTRACT aspects beeshoney Caatinga LMeliponini L Meliponini subnitida sp. sp Lwerecollected werecollected Norte A parameters moisture acidity HMF activity conductivity F fromM M content

RESUMO A indústria têxtil consome um volume significativo de água no processo de tingimento das fibras. As águas residuais geradas no processamento, além de turvas, devido à presença de corantes que não se fixam na fibra durante o processo de tingimento, são prejudiciais ao ambiente aquático e também aos seres humanos. Esse efluente deve passar por um processo de tratamento antes de ser lançado em corpos hídricos. O tratamento de águas contaminadas com o uso de bioadsorventes possui como vantagens o baixo custo de material e reciclagem de resíduo natural. Baseado no exposto, o objetivo deste trabalho foi avaliar a capacidade de adsorção do corante têxtil Azul Reativo BF-5G em casca de mandioca (Manihot Esculenta Crantz), resíduo proveniente da indústria de farinha de mandioca. A casca de mandioca foi lavada, seca e classificada. Os ensaios de adsorção, em banho finito, foram realizados em diferentes condições de pH, granulometria e temperatura. As capacidades máximas de adsorção, em 24 horas de contato, para as diferentes condições de pH, granulometria e temperatura, foram as seguintes: (qmáx=85,18 mg.g-1; pH=1; 30 °C; 16 mesh); (qmáx=52,30 mg.g-1; pH=0; 30 °C; 32 mesh); (qmáx=92,92 mg.g-1; pH=0; 30 °C; 48 mesh). O processo de adsorção foi espontâneo e exotérmico, o que leva a concluir que a casca de mandioca (Manihot Esculenta Crantz) é um potencial adsorvente para o corante Azul Reativo BF-5G, garantindo economia e praticidade no tratamento desse efluente.

ABSTRACT The textile industry consumes a significant amount of water in the fiber dyeing process. The wastewater generated in the processing, in addition to turbid, due to the presence of dyes that do not stick to the fiber during the dyeing process, are harmful to the aquatic environment and also to humans. This effluent must undergo a treatment process before being released into water bodies. The treatment of contaminated water with the use of bioadsorbers has the advantages of low material cost and recycling of natural waste. Based on the above, the objective of this work was to evaluate the adsorption capacity of the textile dye Blue Reactive BF-5G in cassava peel (Manihot Esculenta Crantz), residue from the cassava flour industry. The cassava peel was washed, dried and classified. The adsorption tests, in finite bath, were carried out under different conditions of pH, granulometry and temperature. The maximum adsorption capacities, in 24 hours of contact, were as follows: (qmax=85.18 mg.g-1; pH=1; 30 °C; 180 rpm; 16 mesh); (qmax=52.30 mg.g-1; pH=0; 30 °C; 180 rpm; 32 mesh); (qmax=92.92 mg.g-1; pH=0; 30 °C; 180 rpm; 48 mesh). The adsorption process was spontaneous and exothermic, which leads to the conclusion that the cassava peel (Manihot Esculenta Crantz) is a potential adsorbent for the Reactive Blue BF-5G dye, ensuring economy and practicality in the treatment of this effluent.

ABSTRACT. The aim of this study was to evaluate the physicochemical quality and bioactive compounds of Apis mellifera honey as well as the alterations in the quality of A. mellifera honey after being used in the feeding of Melipona subnitida colonies. A. mellifera honeys were collected in apiaries, homogenised and used as feed for M. subnitida bees for 30 days. Every five days, honey samples were collected and evaluated for physicochemical characteristics and bioactive compounds. The treatments consisted of natural honeys of A. mellifera and M. subnitida and honey of M. subnitida bee after being fed with A. mellifera honey (modified honey). M. subnitida bees, when fed with honey from A. mellifera, modified some of its characteristics, such as moisture, reducing sugars, diastase activity, colour and flavonoid content. Natural and modified honeys of A. mellifera were similar to each other and different from M. subnitida honey in terms of minerals, free acidity, electrical conductivity, phenolic content and antioxidant activity. Treatments were similar in terms of sucrose, insoluble matter, hydroxymethylfurfural and water activity. In general, the quality attributes of the modified honey were closer to the honey of A. mellifera than to the natural M. subnitida honey.

Resumo O objetivo deste estudo foi determinar o tamanho da amostra mais eficiente necessário para estimar a média dos caracteres de qualidade pós-colheita de mangas ‘Palmer’ colhidas em duas estações. Cinquenta mangas foram coletadas no estágio de maturação 2, no inverno (junho de 2020) e na primavera (outubro de 2020), e avaliadas quanto à massa, comprimento, diâmetros ventral e transversal, L*, C* e hº de casca e de polpa, matéria seca, firmeza, sólidos solúveis (SS), acidez titulável (AT) e relação SS/AT. De acordo com os resultados, o coeficiente de variação (CV) dos caracteres de qualidade dos frutos variou de 2,1 a 18,1%. O maior CV, em ambas as safras, foi observado para a relação SS/AT, enquanto o menor foi reportado para hº da polpa. Para estimar a média dos caracteres físico-químicos de mangas ‘Palmer’, são necessários 12 frutos na colheita de inverno e 14 da primavera, considerando um erro de estimativa de 10% e um intervalo de confiança de 95%. A AT e a relação SS/AT exigiram o maior tamanho de amostra, enquanto L* e hº exigiram o menor tamanho de amostra. Conclui-se que a variabilidade foi diferente entre os caracteres físico-químicas e as estações, implicando que diferentes tamanhos de amostra são necessários para estimar a média de diferentes caracteres de qualidade em diferentes estações.

Abstract The objective of this study was to determine the most efficient sample size required to estimate the mean of postharvest quality traits of ‘Palmer’ mangoes harvested in two growing seasons. A total of 50 mangoes were harvested at maturity stage 2, in winter (June 2020) and spring (October 2020), and evaluated for weight, length, ventral and transverse diameter, skin and pulp L*, C* and hº, dry matter, firmness, soluble solids (SS), titratable acidity (TA) and the SS/TA ratio. According to the results, the coefficient of variation (CV) of fruit quality traits ranged from 2.1% to 18.1%. The highest CV in both harvests was observed for the SS/TA ratio, while the lowest was reported for pulp hº. In order to estimate the mean of physicochemical traits of ‘Palmer’ mangoes, 12 fruits are needed in the winter and 14 in the spring, considering an estimation error of 10% and a confidence interval of 95%. TA and the SS/TA ratio required the highest sample size, while L* and hº required the lowest sample size. In conclusion, the variability was different among physicochemical traits and seasons, implying that different sample sizes are required to estimate the mean of different quality traits in different growing seasons.

RESUMO Filmes biopoliméricos podem substituir vantajosamente polímeros de origem petroquímica em diversas áreas, como a de embalagem de frutas e hortaliças. Como esses produtos apresentam respiração e transpiração mesmo após a colheita, as propriedades de barreira e de resistência à água do material são cruciais para o cumprimento de seu propósito. Neste trabalho foram obtidos filmes biopoliméricos baseados em fécula de mandioca (0-3%), quitosana (0-3%), cera de carnaúba (0; 0,2%) e glicerol (0,6%) e suas propriedades de interesse foram determinadas. A incorporação da cera reduziu em média 20% a taxa de permeabilidade ao vapor d’água (TPVA), em relação aos filmes sem cera. Dentre os filmes contendo cera, 1c (3% de fécula) e 2c (2% de fécula e 1% de quitosana) apresentaram valores mais baixos de TPVA, 12,55 g/m²h e 12,42 g/m²h respectivamente, sendo então submetidos a outras caracterizações que revelaram que a substituição parcial da fécula pela quitosana não afetou a espessura dos filmes, causou decréscimo de 14% em sua solubilidade e melhorou suas propriedades mecânicas, o que significa aumento em seu potencial para a aplicação pretendida.

ABSTRACT Biopolymer films can advantageously substitute polymers of petrochemical origin in several areas, such as packaging of fruits and vegetables. As these products exhibit breathability and perspiration even after harvesting, barrier properties and water resistance of the packaging material are crucial. In this work, biopolymer films based on cassava starch (0-3%), chitosan (0-3%), carnauba wax (0; 0.2%) and glycerol (0,6%) were obtained and their properties of interest were determined. The wax incorporation reduced on average 20% of the water vapor transmission rate, WVTR, in relation to the films without wax. Among the films containing wax, 1c (3% starch) and 2c (2% starch; 1% chitosan) presented lower values of WVTR, 12.55 g / m²h and 12.42 g / m²h respectively, were then subjected to other characterizations that revealed that the partial replacement of starch by chitosan did not affect the film thickness, caused a decrease of 14% in its solubility and improved mechanical properties, which means increase in its potential for the intended application.

RESUMO A indústria têxtil produz efluentes ricos em corantes que, quando liberados em corpos hídricos, dificultam a penetração da luz solar, prejudicando os processos fotossintéticos. Além disso, os corantes foram indicados como substâncias potencialmente tóxicas. Em geral, os processos de remoção desses contaminantes têm sido muito estudados, destacando-se a técnica de adsorção por sua alta eficiência, além de vantagens operacionais e a possibilidade de reutilização de resíduos agrícolas como adsorventes, beneficiando o meio ambiente e reduzindo custos. O presente trabalho teve como objetivo estudar o desempenho do mesocarpo de coco utilizado como adsorvente no processo de branqueamento de efluente sintético contendo 25 g.L-1 de corante vermelho reativo 195. Os adsorventes foram caracterizados por granulometria, análise termogravimétrica e potencial de carga zero. Realizou-se estudo cinético e de equilíbrio, aplicando-se modelos cinéticos e isotermas de adsorção. O adsorvente exibiu eficiência de remoção de 89,92 % em 120 min. A capacidade máxima de adsorção foi de 24,04 g.g-1 a 30 °C. O estudo cinético mostrou que os dados foram melhor ajustados pelo modelo de Elovich, indicando quimissorção lenta. O estudo termodinâmico mostrou que o processo de adsorção é exotérmico e espontâneo para todas as temperaturas avaliadas.

ABSTRACT The textile industry produces dye-rich effluents that when released in hydric bodies hamper the penetration of sunlight, impairing photosynthetic processes. Besides that, dyes have been indicated as potentially toxic substances. In general, the processes of removing of these contaminants have been much studied, with the technique of adsorption standing out for its high efficiency, in addition to operational advantages and the possibility of reuse agricultural waste as adsorbents, benefiting the environment and reducing costs. The present work had as objective to study the performance of coconut mesocarp utilized as adsorbent in the bleaching process of synthetic effluent containing 25 g.L-1 of reactive red 195 dye. The adsorbent were characterized by granulometry, thermogravimetric analysis and zero point charge. Kinetic and balance study was realized, applying kinetic models and adsorption isotherms. The adsorbent exhibited removal efficiency of 89.92 % in 120 min. The maximum adsorption capacity was 24.04 g.g-1 at 30 °C. The kinetic study showed that the data was better adjusted by an Elovich equation, indicating slow chemisorption. The thermodynamic study exhibited that the adsorption process is exothermic and spontaneous for all the temperatures evaluated.

Concern for sustainable development has provided significant improvements in the development of biodegradable materials. This work aims to evaluate, through a central composite design (CCD), the mechanical properties of cassava starch-based biocomposites manufactured with different compositions of carnauba wax (CW), sisal fiber (SF) and glycerol (G). The biocomposites were obtained by casting method. The tensile strength (TS), modulus of elasticity (ME) and elongation at break (El) for the biocomposites were determined by tensile tests. Representative models were obtained to explain changes in mechanical properties of biocomposites as function of composition variables. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to elucidate interactions between the starch matrix and additives A biocomposite with 7.5% sisal fiber, 10% carnauba wax and 10% glycerol showed the best properties to possible applications.

This work aims investigate the changes on tensile properties of biocomposites obtained by addition of carnauba wax and coconut fibers in a corn starch matrix. The influence of carnauba wax and coconut fibers contents on tensile strength, modulus of elasticity and elongation at break was studied using a response surface methodology. A central composite design based on three levels of carnauba wax content (0, 10 and 20 %) and coconut fibers content (0, 10 and 20 %) was elaborated. Empirical models were obtained to describe these properties as function of coconut fiber and carnauba wax contents. Optical microscopy was carried out to visualize the dispersion and interactions between coconut fibers, carnauba wax and starch matrix in the biocomposites. In presence of carnauba wax, the biocomposite became more compact and with a better interaction between the corn starch-based matrix and coconut fibers reinforcement. It was observed that tensile strength and modulus of elasticity rise with the increase in carnauba wax and coconut fiber contents. Moreover, the elongation at break increases with the addition of coconut fiber, while a decrease in the values of this property occurs with the addition of carnauba wax.

Biopolymer films have several industrial applications because they are environmentally sustainable. Cassava starch is a biopolymer that is easily available, but has limitations: it is hydrophilic, poorly resistant and degradable. The improvement of these properties was proposed in this research from the use of bentonite clay (BT) as a filling material. The compatibilization of this in the polymer matrix was obtained by ion exchange with an organic anionic surfactant. The formation of intercalated or exfoliated starch nanocomposites in the presence of natural or modified clay was characterized by XRD, FTIR, AFM and SEM. The improvement of water vapor, thermal and mechanical properties was investigated by WVP, solubility, TGA and tensile test. The starch nanocomposites in the presence of modified clay showed a better result than those of natural clay. There was no significant difference in the color of the starch film in the presence of the natural or modified clay.

Coatings technologies with biopolymeric films are effective in maintaining the chemical and sensory characteristics of several fruits. Cassava starch is an attractive biopolymeric because of its renewable characteristics and low cost, but it has a high transfer rate of water vapor. Hydrophilic compounds of organically modified montmorillonite clay by ion exchange can be used to improve the limiting properties of starch in exchange for additives such as lipids. The solutions prepared with 5% m/v starch / 5% m/m cationic / anionic clay and uncoated were applied in caja fruit, harvested at physiological maturity, selected for absence of defects and color uniformity. The experimental design was performed with four storage times (0, 3, 6 and 9 days). For the maturation index, there was an isolated effect of the type of coating and storage time, showing the composite films of modified cationic clay with greater MI of the fruits in comparison to the control fruits.

Films and edible coatings of natural polymers have been proposed as an attractive alternative for conventional plastic packaging because of their excellent biodegradability and biocompatibility. However, natural polymers, like chitosan, are hydrophilic and present poor water barrier properties. The addition of wax or other hydrophobic substances decreases water permeability of natural polymers but can increases their opacity.The objective of this work was to produce biofilms based on chitosan and different concentrations of carnauba wax and analyze their optical and barrier properties. The films were obtained by dissolving chitosan in acetic acid. Carnauba wax was incorporated into film-forming solutions at0, 15, 30, 40 and 50% (w/w). The opacity increased with higher concentrations of wax, the film with 50% of wax showed the highest value with an increase of 10.5% compared to the control film. The water vapor permeability decreased from 2.73 g.mm/kPa.m2.h (0% of wax) to 0.77 g.mm/h.kPa.m2 (40% of wax). The solubility decreased to about 60% over the control films, and the contact angle increased from 53º to 83º, in film with 0 and 50% of wax, respectively.

RESUMO Dentre as diversas práticas culturais utilizadas no meloeiro, aquelas que alteram a relação fonte: dreno, como poda de hastes e raleio de frutos, influenciam diretamente na produção, afetam o tamanho dos frutos e sua composição, incluindo os teores de açúcares e vitaminas. Objetivou-se, com este trabalho, avaliar a influência da poda da haste principal e da época de realização do raleio de frutos na qualidade pós-colheita de melão. Para isto, dois experimentos foram implantados no município de Mossoró-RN, cada um com um híbrido (Amaregal e Banzai). Cada experimento foi conduzido em blocos ao acaso, com esquema fatorial (2 x 4) + 1, sendo 2 níveis do fator poda (sem poda e com poda), 4 níveis do fator raleio (3, 6, 9 e 12 DARM - dias após a retirada da manta agrotêxtil) e uma testemunha (sem poda e sem raleio), e quatro blocos. Os frutos foram colhidos na maturidade comercial e transportados para o Laboratório de Tecnologia de Alimentos da UFERSA, onde foram avaliados quanto às seguintes características: massa, diâmetro, comprimento, espessura de polpa, firmeza da polpa, sólidos solúveis, pH, acidez titulável, relação sólidos solúveis: acidez titulável e vitamina C. Não houve interação dos fatores em nenhum dos experimentos. A acidez titulável (0,077%) e o teor de vitamina C (3,4 mg/100g) do melão Amaregal e os sólidos solúveis (10,2%) do melão Banzai foram menores nos tratamentos com poda da haste. No melão Amaregal, os frutos apresentaram maior comprimento (134 mm) e firmeza de polpa (40 N) quando o raleio foi efetuado aos 6 DARM e à medida que a realização do raleio foi retardada houve decréscimo nos valores de sólidos solúveis, relação SS: AT e pH. No melão Banzai, os frutos tiveram maior espessura de polpa (33,5 mm) e relação SS: AT (247,5) quando o raleio foi efetuado aos 6 DARM, no entanto, o retardamento na realização do raleio propiciou incremento pH e no teor de vitamina C dos frutos. Conclui-se que a poda da haste principal e a época de realização do raleio de frutos influenciou a qualidade dos melões Amaregal e Banzai de maneiras diferentes.

ABSTRACT Among many management practices used in melon crops, those that change source: sink relationship, such as pruning and fruit thinning, directly influence production, affect fruit size and its composition, including sugar and vitamin contents. The objective of this study was to evaluate the influence of pruning of the main stem and time of fruit thinning in melon postharvest quality. Thus, two experiments were set up in Mossoró, state of Rio Grande do Norte, each with a melon hybrid (Amaregal and Banzai). Each experiment was conducted in a randomized block, in a (2 x 4) + 1 factorial design, 2 pruning management (with and without pruning), 4 levels of fruit thinning (3, 6, 9 and 12 DARB - days after removal agro textile blanket) and a control (without pruning and thinning), and four replications. Fruits were harvested at commercial maturity and transported to the Laboratory of Food Technology of UFERSA, where they were evaluated for the following characteristics: weight, diameter, length, flesh thickness, flesh firmness, soluble solids, pH, and titratable acidity, soluble solids: titratable acidity ratio and vitamin C. No interaction between factors in any of the experiments was found. Titratable acidity (0.077%) and vitamin C content (3.4 mg/100 g) in Amaregal melon and soluble solids (10.2%) in Banzai melon were lower in the treatments with stem pruning. In Amaregal melon, fruits showed longer length (134 mm) and greater flesh firmness (40 N) when thinning was carried out on 6 DARB, and as thinning was delayed, it found a decrease in the values of soluble solids, SS: TA ratio and pH. In Banzai melon, fruits showed greater flesh thickness (33.5 mm) and SS: TA (247.5) ratio when thinning was carried out on 6 DARB. However, delay in thinning promoted an increase in pH and vitamin C content of the fruits. Pruning of the main stem and thinning season had effect on the quality of Amaregal and Banzai melons in different ways.

RESUMO A manutenção da temperatura de campo dos frutos é prejudicial à sua conservação, porque acelera o metabolismo celular e a transpiração e, como consequência, reduz sua vida útil. Este trabalho teve por objetivo avaliar a conservação do melão Cantaloupe, híbrido 'Torreon', com o uso de hidrorresfriamento. Os frutos foram colhidos em setembro de 2007, pela manhã, na Fazenda Nova Califórnia, localizada no município de Mossoró-RN, na maturidade comercial (60 dias após a semeadura). Na casa de embalagem da fazenda, um grupo de frutos foi pré-resfriado (imersão em água fria, a 5 ºC, por 5 min.), enquanto o outro grupo permaneceu sem resfriar. Logo após, os dois grupos foram submetidos a um pré-resfriamento em túneis de circulação forçada de ar, à temperatura de 7 ºC, até que a polpa atingisse 10 ºC. Ambos foram armazenados por 0, 14, 21, 28 e 35 dias, sob atmosfera modificada, a 3 ± 1 oC e 90 ± 5% de UR. Após cada intervalo de tempo, os frutos foram transferidos para uma câmara regulada a 20 ± 2 oC e 80 ± 5% de UR, em que permaneceram por sete dias. Foram avaliadas as seguintes características: aparência externa e aparência interna dos frutos, perda de massa, firmeza da polpa, sólidos solúveis e acidez titulável. O delineamento experimental foi inteiramente casualizado, em esquema de parcelas subdivididas, com quatro repetições de três frutos. As parcelas foram constituídas pelas condições de hidrorresfriamento (com e sem imersão dos frutos em água fria) e, as sub-parcelas, pelo tempo de armazenamento (0, 14, 21, 28 e 35 dias). O hidrorresfriamento foi eficiente em manter a firmeza e os teores de sólidos solúveis dos frutos e abreviou o tempo de pré-resfriamento no túnel, porém, não prolongou o tempo de vida útil.

ABSTRACT Maintaining cantaloupe melon at field temperature impairs conservation as it speeds up cell metabolism and transpiration, and, consequently, reduces shelf life. This study aimed to evaluate the conservation of Torreon hybrid cantaloupe using the hydrocooling treatment. Fruits were harvested at the commercial maturity stage (60 days after planting), in the morning, at the Nova California Farm, municipality of Mossoró-RN, in September 2007. One set of fruit was immersed in chilled water at 5 ºC for 5 min, at the packing house, while the remaining set was not hydro cooled. Then, both sets (treated and untreated with hydrocooling) were pre-cooled in air forced tunnels at 7 ºC, until the temperature in the pulp reached 10 ºC. Both fruit sets were stored for 0, 14, 21, 28 and 35 days under modified atmosphere at 3 ± 1 oC and 90 ± 5% RH. After each storage period, the fruits were incubated in an atmosphere-controlled chamber at 20 ± 2 oC and 80 ± 5% de RH, for seven days. The following characteristics were evaluated: external and internal appearance, mass loss, soluble solids, firmness and titrable acidity. The experiment was arranged in a completely randomized split-plot design with four replications of three fruits. The plots consisted of the hydrocooling conditions (with and without fruit soaking in chilled water), and the sub-plots consisted of the storage times (0, 14, 21, 28 and 35 days).The treatment with hydrocooling was efficient in keeping the firmness and soluble solids of the fruits and shortened the pre-cooling time in the cooling tunnel. However, hydrocooling did not increase fruit shelf-life.

RESUMOO uso racional de nutrientes é de fundamental importância para obtenção de alta produção e com alta qualidade nutricional. Este trabalho foi desenvolvido com o objetivo de avaliar a qualidade de frutos de pimentão cultivado sob diferentes manejos de fertirrigação e níveis de nitrogênio e potássio. Adotou-se o delineamento experimental em blocos casualizados, em esquema fatorial 3 x 6 com quatro repetições. Os tratamentos resultaram da combinação de três sistemas de manejo da fertirrigação (M1-Fertirrigação a partir da marcha de absorção; M2-Fertirrigação a partir do monitoramento da condutividade da solução do solo; M3-monitoramento da concentração de íons de N e K na solução do solo) com seis níveis de N e K (N0K0, N50K50, N100K100, N150K150, N200K200 e N300K300 (%) da dose recomendada para a cultura sob fertirrigação convencional (M1) ou hidroponia (M2 e M3)). A qualidade dos frutos foi avaliada para as seguintes características: pH, sólidos solúveis, acidez titulável, teor de vitamina C e relação sólidos solúveis/acidez titulável. Os manejos de fertirrigação afetaram apenas o teor de sólidos solúveis (SS) e a acidez titulável (AT), reduzindo os SS e AT. As variáveis estudadas foram ajustadas com modelos quadráticos para os níveis de N e K.

ABSTRACTThe rational use of nutrients is of fundamental importance for obtaining high productivity of high nutritional quality. This work was developed with the aim of evaluating the quality of pepper fruit grown under different fertigation managements and different levels of nitrogen and potassium. The experimental design was of randomised blocks in a 3 x 6 factorial scheme with four replications. The treatments resulted from the combination of three fertigation managements (M1-based on the rate of absorption; M2-monitoring the conductivity of the soil solution; M3-monitoring concentrations of N and K ions in the soil solution) with six levels of N and K (N0K0, N50K50, N100K100, N150K150, N200K200 and N300K300) as a percentage of the recommended dosage for the crop under conventional fertigation (M1) or hydroponics (M2 and M3). Fruit quality was evaluated for the following characteristics: pH, soluble solids, titratable acidity, vitamin C content and the ratio of soluble solids to titratable acidity. The different fertigation managements only affected the levels of soluble solids (SS) and titratable acidity (TA), reducing the SS and TA. The variables under study were adjusted for the levels of N and K using quadratic models.