Resumo A longevidade das flores de corte é limitada por sua natureza efêmera e por diversos estresses. De forma geral, a diminuição da absorção de água, esgotamento dos carboidratos armazenados, aumento da atividade respiratória e produção de etileno são reflexos senescência floral. Uma ampla gama de técnicas está disponível para estender a preservação de flores, incluindo o uso de conservantes de flores, inibidores da ação do etileno, reguladores de crescimento e controle de temperatura e desidratação das flores. O uso de sacarose em solução pulsante ou como constituinte de solução de vaso pode estender a vida de vaso das flores, melhorando o balanço hídrico, estimulando a abertura das flores ou retardando a senescência devido à menor síntese de etileno. Os inibidores da produção e ação do etileno afetam a longevidade, estendendo a vida de vaso de algumas flores sensíveis ao etileno. As flores têm intensa atividade respiratória, o que pode esgotar as reservas limitadas de carboidratos armazenados nas hastes cortadas. A redução da temperatura reduz tremendamente a produção de CO2 e etileno, bem como a sua ação. No entanto, em flores sensíveis ao frio como ave-do-paraíso, helicônia, orquídea e gengibre não podem ser armazenadas abaixo de 10 a 13ºC devido ao intenso desenvolvimento de descoloração do tecido.

Abstract The longevity of cut flowers is limited by their ephemeral nature and by multiple stresses. Impairment in water uptake, depletion of stored carbohydrates, increases in both respiratory activity and ethylene production are signatures of flower senescence. A wide range of techniques is available to extend flower preservation, including the use of flower preservative solutions, ethylene action inhibitors, growth regulators, and control of temperature and flower dehydration. The use of sucrose in pulsing solution, or as a component of vase solution, extends the vase life of flowers by either improving water balance and energy or delaying the senescence via reductions in ethylene biosynthesis. Inhibitors of ethylene production and action affect the longevity by extending the vase life of some ethylene-sensitive flowers. Flowers have intense respiratory activity, which may deplete the limited reserves of carbohydrates in the tissues. Lower temperatures markedly reduce both carbon dioxide concentration and ethylene production as well as its action. However, chilling-sensitive flowers, such as bird-of-paradise, heliconia, orchid, and ginger, cannot be stored below 10 to 13°C due to the intense development of tissue discoloration.

RESUMEN En condiciones de cultivo que favorezca el crecimiento de la parte aérea de la planta, la adopción de prácticas de manejo que reduzca el tamaño de las plantas puede ser una alternativa para aumentar el rendimiento de los tubérculos. El objetivo de este trabajo fue evaluar el efecto del paclobutrazol sobre el crecimiento vegetativo y la partición de la materia seca de la planta de papa cv. Markies cultivado en verano en el estado de Minas Gerais, Brasil. Los tratamientos fueron 0,1; 1,0; 10 y 100 mg L-1 de paclobutrazol (PBZ) aplicado a las semillas germinadas antes de plantar y um control tratado con agua. PBZ fue eficiente em la reducción de la altura de la planta. Los tratamientos con dosis de 10 y 100 mg L-1 de PBZ retrasaron la aparición de la parte aérea y el comienzo de la tuberización de la planta. PBZ a 0,1 mg L-1 redujo la longitud del tallo en un 18%, pero no difirió con el control en relación al contenido de masa fresca y seca, la producción total, la gravedad específica y el contenido de almidón de los tubérculos. El tratamiento de tubérculos de papa con PBZ a 0,1 mg L-1 presentan plantas más pequeñas y compactas, que podrían ser adecuadas para una plantación más densa para maximizar la población de plantas y aumentar el rendimiento económico por unidad de área.

ABSTRACT Under cultivation conditions that favor the growth of plant shoots, the adoption of management practices that reduce the size of potato plants can be an alternative for increasing tuber yield. The objective of this study was to evaluate the effect of paclobutrazol on vegetative growth and dry matter partitioning in the potato plant cv. Markies, cultivated under summer conditions in the state of Minas Gerais. The treatments were 0.1, 1.0, 10 and 100 mg L-1 of paclobutrazol (PBZ), applied to sprouted seeds before planting and control with water. PBZ was efficient in reducing plant height. The PBZ treatments with doses of 10 and 100 mg L-1 delayed the emergence of shoots and the beginning of plant tuberization. PBZ at 0.1 mg L-1 reduced the lengh of the stem by 18% but did not differ from the control for the fresh and dry mass content, total production, specific gravity and starch content of tubers. The treatment with seed potatoes and PBZ at 0.1 mg L-1 resulted in smaller, more compact plants, which could be suitable for more densely planted cultivations in order to maximize plant populations and increase economic return per unit of area.

ABSTRACT. The increased demand for potato by the Brazilian processing industry requires long term refrigerated storage, but after a few months, natural dormancy ends, and sprouts start to grow. Thus, sprout inhibitors are necessary to reduce the rate of growth and allow further storage. The purpose of research described here was to determine the effects clove and menthol essential oils have on the inhibition of sprout growth in non-dormant ‘Asterix’ tubers. Both eugenol and menthol treatments reduced the rate of sprout growth during storage at 8oC for up to 50 days. Eugenol and menthol essential oils diminished the rate of accumulation of reducing sugar, which are responsible for browning of French fries. Color after frying was within acceptable levels when the tubers were treated with eugenol or menthol essential oils.

ABSTRACT Two trials were carried out to evaluate the effect of groups of organic minerals with different chemical characteristics on the performance, egg quality, biometry of digestive organs, and bone quality of laying hens in the first and second laying cycles. In the first cycle, 180 layers at 72 weeks were used in a completely randomized design (CRD) with four treatments and five replicates with nine birds each. In the second cycle, 216 layers at 94 weeks of age were used in a CRD with four treatments and six replicates with nine birds each. Birds were fed the following diets: treatment 1 - basal diet (inorganic minerals); treatment 2 - basal diet + amino acid chelated minerals (Cu, Fe, Mn, and Zn) + selenium yeast; treatment 3 - basal diet + mineral-amino acid complex (Mn, Zn, and Cu); and treatment 4 - basal diet + metal chelate (Mn, Zn, and Cu) + methionine hydroxy analogue. The following performance variables were evaluated: feed intake (g/bird/day), egg production (%), egg weight (g), egg mass (g/bird/day), conversion per mass (kg/kg), and conversion per dozen eggs (kg/dz). In the egg, the percentages of albumen, yolk, and shell; eggshell thickness (mm); and specific gravity (g/cm3) were determined. The relative weights (%) of the proventriculus, gizzard, liver, pancreas, and intestines were also measured. Lastly, in the tibiae, the weight (g), length (mm), resistance (kgf/cm2), deformity (mm), Seedor index (mg/mm), and mineral matter content (g/kg) were measured. The variables were not influenced by the groups of organic minerals used. Groups of organic minerals with different chemical characteristics can be used in layer diets without affecting their performance, egg quality, digestive organs, or bone quality.

ABSTRACT The breakdown of dormancy and early sprouting is one of the main causes of losses of stored potatoes. Sprouting control becomes important especially when tubers are submitted to long-term storage for further processing by the potato industry. The objective of this work is to evaluate the effect of organic sprout inhibitors, eugenol and menthol essential oils, on the suppression of growth on non-dormant ‘Asterix’ tubers stored at 8 °C. Administration of eugenol and menthol essential oils reduced the number and the length of sprouts during cold storage up to fifty days. Nevertheless, the essential oils stimulated the break of bud apical dominance, stimulating auxiliary buds growth. The effect of the oils was restricted to inducing necrosis of superficial sprout cells without any apparent effect on the skin periderm structure. Repeated applications of oils are necessary to prolong the inhibitory effects of the essential oils on sprouts growth.

RESUMO O objetivo do trabalho foi avaliar a sensibilidade e as respostas fisiológicas da abobrinha ‘Menina Brasileira’ a diferentes doses de etileno. Os frutos foram colhidos, homogeneizados e colocados em baldes de 20 litros hermeticamente fechados, nos quais foram aplicadas doses de etileno nas concentrações de 0,1; 1,0; 10; 100 e 1000 μL L-1 durante 24 h, além do controle. Posteriormente, os frutos foram retirados dos baldes e mantidos sobre bancada, onde aos dias 0, 2, 4, 6 e 8 foram avaliados quanto à perda de peso fresco e teores de açúcar solúvel total, açúcar redutor e não redutor, amido, clorofila, conteúdo de malonaldeído e extravasamento de eletrólitos. Os frutos da abobrinha ‘Menina Brasileira’ apresentaram sensibilidade ao etileno exógeno sem estimular a perda de peso fresco. Ademais, os frutos exibiram pequenas alterações nos atributos de qualidade nutricional, além de mudanças no aspecto externo dos frutos, como diminuição do teor de clorofila e injúria por danos à membrana celular, caracterizada pelo aumento do conteúdo de malonaldeído e extravasamento de eletrólitos. Essas alterações foram estimuladas em resposta ao aumento da concentração de etileno.

ABSTRACT The purpose of this study was to evaluate the sensitivity and the physiological responses of summer squash ‘Menina Brasileira’ to ethylene. Immature fruits were harvested and placed in 20 L sealed buckets, in which ethylene was applied at concentrations of 0.1, 1.0, 10, 100, and 1000 μL L-1 for 24 h. Fruits were placed in buckets with no ethylene as a control treatment. Thereafter, the fruits were taken out of the buckets and maintained on bench, wherein on days 0, 2, 4, 6, and 8, they were evaluated regarding the accumulated fresh weight loss, soluble sugars, reducing and non-reducing sugars, starch, total chlorophyll, content of malondialdehyde, and electrolyte leakage. Fruits of summer squash ‘Menina Brasileira’ showed sensitivity to exogenous ethylene with no weight loss stimulation. Additionally, the fruits exhibited small changes in nutritional quality attributes and changes in the external fruit appearance, including decreased chlorophyll content as well as damage to cell membrane characterized by increase in malondialdehyde content and electrolyte leakage. These changes were stimulated by increasing exogenous ethylene concentration.

RESUMO: Espécies do gênero Capsicum estão sendo usados para diversas finalidades e nos últimos anos como planta ornamental de vaso. Apesar da crescente importância comercial, há poucos estudos sobre os fatores ambientais que afetam a sua vida útil de pós-produção destas plantas ornamentais. A presença de etileno induz várias respostas em pimenteiras em vasos, reduzindo a vida útil de prateleira de cultivares sensíveis. Este estudo teve como objetivo avaliar os efeitos do etileno e inibidores da ação do etileno, 1-metilciclopropeno (1-MCP) e tiossulfato de prata (STS) sobre a vida útil de vaso de pimenteiras das cultivares 'Calypso' e 'MG 302'. A cultivar 'MG 302' apresentou sensibilidade intermediária a ação do etileno, enquanto a cultivar 'Calypso' apresentou abscisão completa das folhas quando exposta ao etileno. Em ambas as cultivares, o tratamento STS + Etileno mostrou sintomas de fitotoxicidade nas plantas. O tratamento com 1-MCP + Etileno foi eficaz em retardar a senescência e abscisão apenas para a cultivar 'MG 302', enquanto a cultivar 'Calypso' mostrou abscisão foliar semelhante as plantas controle. Plantas tratadas com STS mostraram maior durabilidade quando comparadas aos outros tratamentos, cerca de seis dias para 'Calypso' e dezoito dias para 'MG 302'. No entanto, as plantas tratadas com 1-MCP também exibiram boa vida útil de prateleira, cerca de seis dias para 'Calypso' e nove dias para a 'MG 302'. Embora o tratamento com STS tenha sido mais eficiente na vida de prateleira das plantas, não bloqueou completamente a ação do etileno e apresentaram algum fitotoxicidade, enquanto o tratamento com 1-MCP teve boa eficiência sem induzir qualquer toxicidade.

ABSTRACT: Species from Capsicum genus are used for different purposes and in more recent years as ornamental potted plant. Despite the increased commercial importance, there are only a few studies on the environmental factors affecting the post-production shelf life of these ornamental plants. The presence of ethylene induces various responses on potted peppers, reducing the shelf life of sensitive cultivars. This study aimed to evaluate the effects of ethylene and the inhibitors of ethylene action, 1-methylcyclopropene (1-MCP) and silver thiosulfate (STS) on the shelf life of potted 'Calypso' and 'MG 302' peppers. Cultivar 'MG 302' showed intermediate sensitivity to ethylene action, while the cultivar 'Calypso' showed complete abscission of leaves when exposed to ethylene. In both cultivars, treatment with STS + Ethylene presented symptoms of phytotoxicity in plants, while treatment with 1-MCP + Ethylene was effective in delaying senescence and abscission for the cultivar 'MG 302', while cultivar 'Calypso' showed abscission similar to control plants. Plants treated with STS showed the longest durability when compared to the other treatments, about six days for 'Calypso' and 18 days for 'MG 302'. Nevertheless, plants treated with 1-MCP also exhibited good shelf life, about six days for 'Calypso' and nine days for the 'MG 302'. Although the treatment with STS was more efficient on the plants shelf life, did not completely block the action of ethylene and exhibited some phytotoxicity, while the treatment with 1-MCP had good efficiency without inducing any toxicity.

RESUMO: Normalmente, não é recomendado o condicionamento de hastes de gladíolo em água durante o armazenamento ou transporte. A hidratação das pétalas acelera a abertura das flores, mesmo em baixa temperatura, o que compromete a qualidade no momento da comercialização. No entanto, para essa espécie, ainda não foi estudado o efeito do armazenamento refrigerado prolongado a seco e nem o seu comportamento quando transferida para a água em temperatura ambiente. O presente estudo teve como objetivo avaliar a vida de vaso e a capacidade de reidratação de hastes florais de gladíolo após armazenamento a seco em baixa temperatura ( Gladiolus grandiflora Hort.). As hastes das cultivares Blue Frost, Gold Field, Traderhorn e Jester foram armazenadas a seco em temperatura de 5 ± 1 ºC e umidade relativa de 85% por 12, 24, 36 e 48 horas. As hastes controle permaneceram sempre em água deionizada. Após armazenamento, retornaram a água sob condição de temperatura ambiente (22 ± 1 ºC) e foram avaliadas quanto à vida de vaso (adotando o critério de descarte quando 50% das flores basais apresentaram perda de coloração e murcha), variação da massa de matéria fresca (%), taxa de absorção de água e taxa transpiratória, bem como o teor relativo de água das pétalas (%). Em condições de armazenamento a seco em baixa temperatura, por até 36 horas, a vida de vaso não foi afetada, embora tenha ocorrido reidratação incompleta das flores. A capacidade de reidratação da haste está relacionada com a abertura escalonada das flores ao longo da inflorescência.

ABSTRACT: Normally, it is not recommended the conditioning of gladiolus stems in water during storage or transport. Hydration of petals may accelerate flower opening, even at a low temperature, which compromises quality at marketing moment. However, for this species, neither the effect of prolonged dry cold storage nor its behavior when transferred to water at room temperature has been evaluated. The present study aimed to evaluate the vase life and the rehydration capacity of gladiolus flowers ( Gladiolus grandiflora Hort.) after dry storage at low temperature. Flower stems of cultivars Blue Frost, Gold Field, Traderhorn, and Jester were dry-stored at a temperature of 5 ± 1 ºC and relative humidity of 85% for 12, 24, 36, and 48h. Control stems remained always in deionized water. After storage, they were returned to the water at room temperature and evaluated for vase life (adopting the discard criterion when 50% of the basal flowers displayed loss of color and wilting), fresh weight change (%), water uptake rate and transpiration rate, as well as relative water content of the petals (%). In dry cold storage conditions, for up to 36h, the vase life was not affected although incomplete rehydration of the flowers. Rehydration capacity of the stem is linked to the staggered opening of flowers along the inflorescence.

ABSTRACT The gladiolus flower is classified as insensitive to ethylene. Thus, the signals that initiate senescence are poorly understood. This study evaluated the role of abscisic and gibberellic acids on postharvest senescence of 3 cultivars of cut gladiolus flowers (Gladiolus grandiflora Hort.). Stalks were harvested and placed in test tube containing 100 mL distilled water or an aqueous solution of abscisic acid (100 and 150 µM ABA), gibberellic acid (100 µM GA3), and fluridone (1 mM) for 24 h. Subsequently, flower stalks were placed in a test tube with distilled water, and the following variables were determined: stem longevity, fresh weight change, water uptake rate and transpiration rate during the vase life, as well as membrane stability index and lipid peroxidation in 5 stages of flower development. In another experiment, the florets were removed by cutting down the pedicel. After removal, florets were placed in a beaker containing 10 mL distilled water or the following solutions: 100 or 150 µM ABA; 100 µM GA3; 1 mM fluridone; and 100 µM ABA + 100 µM GA3, followed by immersion in distilled water after 24 h in each treatment. Fresh weight change and transpiration rate of florets were assessed every 24 h. Abscisic acid is involved in the induction of senescence-related events in gladiolus flowers, such as high loss of membrane stability and abnormal flower opening. GA3 regulates the action of ABA in the maintenance of cell membrane and opening of gladiolus flowers.