ABSTRACT. This study examined biochemical changes associated with chilling injury (CI) in sweet potato roots stored at low temperatures and reconditioned at ambient temperature. Sweet potato cultivars BRS Amélia and BRS Rubissol were stored at 6 or 13°C for 4 days at ambient temperature (“ambient reconditioning”: 21 ± 2°C). CI on the outer surface of the roots occurred earlier in BRS Amélia than in BRS Rubissol. The CI index on the inner surface of the BRS Amélia was higher when it was stored at 6°C for 40 + 4 days. BRS Amélia showed higher proline content and electrolyte leakage when stored at 6°C. Ascorbate peroxidase was induced by storage at 6°C for 30 + 4 days in BRS Amélia and from 40 + 4 days in BRS Rubissol. The malondialdehyde and phenolic compounds of BRS Rubissol increased during storage at 6°C. CI in both cultivars was associated with increased peroxidase and polyphenol oxidase activities. Storage of sweet potato cultivars at 6°C for 50 + 4 days caused severe damage to the roots. Cultivars BRS Amélia and BRS Rubissol showed similar symptoms of CI and can be characterized as being sensitive to low temperatures.

Resumen En muchos tejidos vegetales, se ha utilizado el acondicionamiento a baja temperatura (LTC) para inducir respuestas adaptativas poscosecha para superar las consecuencias del daño por frío (CI). Este estudio tuvo como objetivo investigar si el LTC es eficaz para reducir la incidencia de daño por frío (CI) en cultivares de batata. Las raíces de batata BRS Cuia y BRS Rubissol se sometieron a almacenamiento en frío (6 °C o 13 °C) y LTC (10 °C durante 7 días, seguido de un segundo almacenamiento a 6 °C). El LTC aumentó la tolerancia de las raíces de la batata al IC mediante la activación del sistema antioxidante, principalmente en el cv. BRS Rubissol, que se asoció notablemente con un mayor contenido de fenoles solubles totales y prolina, así como una mayor actividad de la fenilalanina amonio liasa. Además, no se observaron lesiones externas ni internas en las raíces de LTC, manteniendo la calidad para el procesamiento, lo que indica que el LTC es eficaz para mitigar el daño por frío en los cultivares brasileños de batata.

Abstract In many plant tissues, low-temperature conditioning (LTC) has been used to induce postharvest adaptive responses to overcome chilling injury (CI) consequences. This study aimed to investigate whether LTC is effective in reducing the incidence of chilling injury (CI) in sweet potato cultivars. Sweet potato roots BRS Cuia and BRS Rubissol were submitted to cold storage (6 °C or 13 °C) and LTC (10 °C for 7 d, followed by second storage at 6 °C). LTC increased the tolerance of sweet potato roots to CI via antioxidant system activation, mainly in cv. BRS Rubissol, which was markedly associated with higher content of both total soluble phenolics and proline, as well as increased activity of phenylalanine ammonium lyase. Moreover, no either external or internal injuries were observed in the LTC roots, maintaining the quality for processing, which indicates that the LTC is effective in mitigating chilling injury in Brazilian sweet potato cultivars.

Abstract Sweet potato fried chips have great acceptance and high market value. Sprouting and fresh mass loss of tuberous roots during storage compromise the quality of the processed products. The objective of this work was to evaluate the effect of 1-Methylcyclopropene (1-MCP), amino-oxyacetic acid (AOA), and ethylene on the physico-chemical quality of fresh sweet potato and its relationship with fried color score in processed chips of cv. BRS Rubissol stored at room temperature. During storage, the weight loss, sprouts number, dry matter content, non-enzymatic browning, protein content, soluble phenols fraction, reducing sugars, total amino acids, pH, soluble solids (SS), titratable acidity (TA) and SS/TA ratio were evaluated. The sweet potato roots cv. BRS Rubissol present good potential for processing as fried chips. 1-MCP and AOA treatments reduced the root sprouting, physico-chemical quality was maintained in all treatments and the fried chips showed less browning in all treatments with storage. Since the sprouting process compromises the storage of roots, AOA and 1-MCP treatments may be applied to extend the shelf-life of roots and improve the processing potential.

Resumo A floricultura é uma atividade promissora e de grande importância econômica. Neste contexto, o cultivo de Lilium pumilum Redouté vem recebendo destaque. Contudo, uma das dificuldades enfrentadas pelos floricultores é que grande parte dos produtos se perde antes de chegar ao consumidor, devido às perdas pós-colheita. Tais empecilhos podem ser revertidos por meio de técnicas adequadas, como é o caso do uso de solução de condicionamento (pulsing), a qual tem sido eficaz no controle da senescência precoce. Diante disso, esse estudo teve como objetivo avaliar a influência da solução via pulsing de sacarose, ácido cítrico e tiossulfato de prata sobre a conservação pós-colheita de hastes florais de L. pumilum. Todos os tratamentos promoveram aumento de 1.8±0.3 dias na longevidade, uniformização da abertura floral e menor perda de massa fresca em relação ao controle. Não houve diferença significativa nos teores de clorofila e no teor relativo de água da folha. O tempo de exposição ao pulsing ocasionou diferenças significativas na redução dos teores de antocianina quando comparado ao controle, demonstrando que o uso de solução preservativa aplicada a partir de 6 h, em pulsing, proporciona aumento da vida de vaso para o L. pumilum.

Abstract Floriculture is a promising activity and has great economic importance. In this context, the cultivation of Lilium pumilum Redouté stands out. However, one of the main challenges flower farmers face is that a large part of the products is lost before reaching the final consumer, due to postharvest losses. Such losses can be minimized by adopting some techniques, such as the use of conditioning solution (pulsing), which has been effective in preventing early senescence. In this sense, this study aimed to evaluate the effect of pulsing with sucrose, citric acid and silver thiosulphate on postharvest conservation of L. pumilum cut flowers. All treatments promoted a 1.8±0.3 day increase in longevity, uniformity of floral opening, and reduced fresh weight loss compared to the control (flowers that were not pulse-treated). There was no significant difference in chlorophyll content and leaf relative water content. The time of exposure to pulsing caused significant differences in the reduction of anthocyanin contents when compared to the control, demonstrating that pulsing preservative solution for at least 6 h extends the vase life of L. pumilum cut flowers by two days.

RESUMEN La formación de plántulas es una de las fases más importantes para el ciclo de cultivo de la berenjena. El tipo de sustrato utilizado es uno de los factores decisivos para obtener plántulas de calidad y el consiguiente aumento de la productividad. El objetivo de este estudio fue evaluar el crecimiento de las plántulas de berenjena cultivadas en sustratos alternativos con niveles crecientes de "moinha" (residuo del proceso de molienda en seco de café), en sustitución del sustrato comercial. El experimento se realizó en un diseño completamente al azar, con seis tratamientos y diez repeticiones. Los tratamientos fueron: T1: sustrato comercial (control); T2: 0% de moinha (MO) + 40% de cáscara de arroz quemada (CAQ) + 15% de fibra de coco (FC) + 5% de cáscara de huevo (CH) + 40% de sustrato comercial (SC); T3: 10% MO + 40% CAQ + 15% FC + 5% CH + 30% SC; T4: 20% MO + 40% CAQ + 15% FC + 5% CH + 20% SC; T5: 30% MO + 40% CAQ + 15% FC + 5% CH + 10% SC; T6: 40% MO + 40% CAQ + 15% FC + 5% CH + 0% SC. Se evaluó la conductividad eléctrica de los sustratos y la masa seca total de las plántulas, la altura de la planta y el diámetro del tallo. Se recomienda utilizar el sustrato que contiene 20% de MO + 40% de CAQ + 15% de FC + 5% de CH + 20% de SC.

ABSTRACT Seedling formation is one of the most important phases for the eggplant crop cycle. One of the decisive factors for obtaining quality seedlings and the consequent increase in productivity is the type of substrate used. The objective of this research was to evaluate the growth of eggplant seedlings grown in alternative substrates with increasing levels of "moinha" (residue from the coffee dry milling process) replacing the commercial substrate. The experiment was carried out in a completely randomized design, with six treatments and ten replicates. The treatments were: T1: commercial substrate (control); T2: 0% moinha (MO) + 40% burnt rice husk (BRH) + 15% coconut fiber (CF) + 5% eggshell (ES) + 40% commercial substrate (CS); T3: 10% MO + 40% BRH + 15% CF + 5% ES+ 30% CS; T4: 20% MO + 40% BRH + 15% CF+ 5% ES + 20% CS ; T5: 30% MO + 40% BRH + 15% CF + 5% ES + 10% CS; T6: 40% MO + 40% BRH + 15% CF + 5% ES + 0% CS. The electrical conductivity of the substrates and the seedling total dry mass, plant height and stem diameter were evaluated. It is recommended to use the substrate containing 20% MO + 40% BRH + 15% CF + 5% ES + 20% CS.

RESUMO O cultivo do maxixe é realizado predominantemente de forma rasteira; entretanto, nesse sistema, ocorrem problemas como "barriga branca" e podridão dos frutos. Objetivou-se avaliar formas de tutoramento de plantas de maxixe. O delineamento experimental foi em blocos casualizados, com cinco tratamentos (condução rasteira, tutoramento em rede agrícola, tutoramento mexicano, tutoramento em fitilho vertical com desbrota de todas as hastes secundárias e tutoramento em fitilho vertical com desbrota alternada das hastes secundárias) e quatro repetições. Foram avaliados a massa fresca e número de frutos por planta, comprimento e diâmetro médio de frutos, número e massa fresca de frutos com barriga branca por planta, massa fresca por fruto, produtividade total e os indicadores econômicos renda bruta, renda líquida, taxa de retorno e índice de lucratividade. Para todos os sistemas tutorados, a incidência de frutos com barriga branca foi menor. Os sistemas de rede agrícola (43,75 t ha-1), mexicano (35,94 t ha-1) e fitilho vertical com desbrota alternada das hastes secundárias (22,24 t ha-1) proporcionaram produtividades superiores ao cultivo rasteiro. O melhor indicador econômico (US$ 21.031,46 ha-1) foi observado com o uso da rede agrícola, sendo o mais recomendado para o cultivo de maxixe.

ABSTRACT The bur gherkin cultivation is predominantly carried out without a staking system, but problems such as the "white belly" and fruit rot occur in this system. This study aimed to evaluate staking systems for bur gherkin plants. The experimental design was randomized blocks, with five treatments (no staking, agricultural netting staking, Mexican staking, vertical ribbon with total secondary stem thinning and vertical ribbon with alternate secondary stem thinning) and four replicates. The fresh mass and number of fruits per plant, fruit length and average diameter, number and fresh mass of fruits with white belly per plant, fresh mass per fruit and total yield were evaluated, as well as the economic indicators gross income, net income, rate of return and profitability index. For all the staking systems, the incidence of fruits with white belly was lower. The agricultural netting (43.75 t ha-1), Mexican (35.94 t ha-1) and vertical ribbon with alternate secondary stem thinning (22.24 t ha-1) systems promoted yields superior to that for no staking. The best economic indicator (US$ 21,031.46 ha-1) was observed for the agricultural netting staking, which is the most recommended for the bur gherkin cultivation.

Abstract Studies about crop residue management have become essential due to the possibility of their use in forest seedlings production. This study evaluated the effect of coffee moinha (MO) on substrates composed of vermiculite (VE), coconut fiber (CF) and carbonized rice husk (CRH) in the development of Eucalyptus seedlings. The experiment was conducted in a completely randomized design, with five treatments of increasing proportions of MO/decreasing proportions of CRH (0/28, 7/21, 14/14, 21/7 and 28/0%) and fixed proportions of VE (36%) and CF (36%) in the substrate. At 85 days after planting, the following parameters were assessed: shoot height, stem diameter, root dry mass, shoot dry mass, emergence percentage and Dickson’s quality index (DQI). The results showed CRH could be fully substituted by MO (28%) in the substrate composition because the assessed variables presented lower values than the control treatment (0% MO + 28% CRH + 36% VE + 36% CF). Moreover, the maximum vegetative development in Eucalyptus seedlings was achieved when CRH was replaced by up to 20% MO. In this way, MO becomes an alternative as a substrate component for Eucalyptus seedlings production.

RESUMO Estudos relacionados ao aproveitamento de resíduos agrícolas como substratos alternativos aos comerciais tornaram-se fundamentais por minimizar o risco de contaminação ambiental decorrente do descarte inadequado, além de diminuir os custos de produção de mudas. Assim, objetivou-se avaliar as variáveis de crescimento e a qualidade de mudas de pepino produzidas em substratos com diferentes composições de resíduos agrícolas, em substituição total ao substrato comercial. O experimento foi realizado no delineamento inteiramente casualizado, com seis tratamentos e dez repetições, sendo cinco tratamentos com proporções crescentes de moinha/decrescentes de casca de arroz (0/40; 10/30; 20/20; 30/10 e 40/0%) e proporções fixas de fibra de coco (15%), casca de ovo (5%) e casca de pinus (40%), e um tratamento controle com substrato comercial (Bioplant®). As variáveis avaliadas foram: condutividade elétrica do substrato, altura da planta, diâmetro do colo, número de folhas, Índice de Qualidade de Dickson (IQD) e massas secas da raiz e da parte aérea. Os substratos alternativos podem substituir o substrato comercial, sem que haja prejuízos à qualidade de mudas de pepino. Entretanto, o substrato contendo 40% de moinha, 0% de casca de arroz, 15% de fibra de coco, 5% de casca de ovo e 40% de casca de pinus proporciona os maiores valores para todas as variáveis avaliadas, sendo o mais indicado na produção de mudas de pepino.

ABSTRACT Studies on the use of agricultural residues as an alternative to commercial substrates have become fundamental tominimising the risk of environmental contamination resulting from inadequate disposal, as well as reducing seedling production costs. This research involved an evaluation of growth variables and quality of cucumber seedlings produced in substrates with different compositions of agricultural waste with a view to providing substitutes for commercial substrate. The experiment was based on a completely randomised design, with six treatments and ten replicates. There were five treatments with increasing proportions of moinha/decreasing proportions of carbonized rice husk (0/40, 10/30, 20/20, 30/10 and 40/0%) and fixed proportions of coconut fibre (15%), eggshell (5%), pine bark (40%), and one commercial substrate treatment as the control (Bioplant®). The variables evaluated were: electrical conductivity of the substrate, plant height, stem diameter, number of leaves, Dickson quality index (DQI) and dry matter of roots and above ground parts. Results show that alternative substrates can replace commercial substrate without impairing the quality of cucumber seedlings. However, the substrate containing 40% of moinha, 0% of rice husk, 15% of coconut fibre, 5% of eggshell and 40% of pine bark resulted in the highest values for all evaluated variables and appears to be the most promising alternative substrate for the production of cucumber seedlings.

RESUMO Estudos relacionados com o aproveitamento de escória de siderurgia tornaram-se imprescindíveis, pela possibilidade de seu uso como componente de substratos na produção de mudas e por esse uso minimizar o risco de contaminação ambiental, decorrente do descarte inadequado. Assim, objetivou-se, com este trabalho, avaliar o efeito de níveis crescentes de escória de siderurgia em substratos, compostos por solo com esterco bovino curtido e areia, nas variáveis de crescimento e na qualidade de mudas de pimenteira dedo-de-moça (Capsicum baccatum L.). Utilizou-se o delineamento em blocos casualizados, tendo como tratamentos cinco concentrações de escória (0%; 2,5%; 5%; 10% e; 20%) e quatro repetições. As avaliações ocorreram aos 55 dias após semeadura, consistindo na contagem do número de folhas, na medição da altura de planta e do diâmetro do coleto, na quantificação das massas secas de folhas e raízes da planta e na determinação do Índice de Qualidade de Dickson. Modelos de regressão foram ajustados (P < 0,05) aos tratamentos com níveis crescentes de escória de siderurgia. A adição em torno de 10% de escória ao substrato proporcionou os maiores valores das variáveis de crescimento, em mudas de pimenteira Dedo-de-moça.

ABSTRACT Studies related to the use of basic slag have become essential due to the possibility of use as a component of substrates in the production of seedlings and to minimize the risk of environmental contamination due to inadequate disposal. The objective of this research was to evaluate the effect of increasing levels of basic slag in substrates composed of soil, bovine manure, and sand on growth variables and quality of “Dedo de moça” pepper plants (Capsicum baccatum L.). A randomized block design was used, with five treatments of basic slag (0, 2.5, 5, 10, and 20%) and four replicates as treatments. The evaluations occurred at 55 days after sowing, consisting of counting the number of leaves, measuring plant height and stem diameter, and quantifying shoot and root dry masses. Regression models were adjusted (P < 0.05) in the treatments with increasing levels of basic slag. The addition of about 10% of basic slag in the substrate provided the highest values of growth variables in Dedo de moça pepper plants.