Use of Natural Products for Post-Harvest Preservation of 'Vega' Cut Roses

Use of natural products as floral preservatives has helped to reduce the indiscriminate use of chemical products in flower preservation. In this study, we tested the ability of certain natural products to maintain the quality and to increase the commercial durability of 'Vega' cut roses. We employed a randomized factorial design with six post-harvest treatments and four evaluation dates. The following treatments were tested: 1) distilled water; 2) methyl jasmonate (350 mu M) applied in a four-hour pulse; 3) methyl jasmonate (500 mu M) spraying; 4) mint oil (100 ppm); 5) ginger oil (100 ppm); and 6) propolis (0.05%) as a maintenance solution. Flowers were kept at 20+/-2 degrees C and 67+/-3% RH. Physiological and qualitative evaluations were conducted. Natural products had a beneficial effect on the shelf life of the flowers. However, for all evaluated parameters, the methyl jasmonate spray was the most efficient treatment to maintain floral quality, resulting in less fresh-mass loss and a lower flower respiratory rate. Methyl jasmonate spray also improved the maintenance of coloration, relative water content and concentration of reducing sugars, thus extending the shelf life of roses.

Synergistic actions of 50°C water and imazalil dip treatments to preserve quality of late-season 'Marsh' grapefruit

Late-season grapefruits (Citrus paradisi Macf. cv. Marsh seedless) were dipped in water at 50°C for 3 min with and without 200 ppm imazalil (IMZ) or 1000 ppm IMZ at 19°C and were subsequently stored at 7°C and 90-95% relative humidity (RH) for 11 weeks plus one week at 21°C and approximately 75% RH to simulate a marketing period (SMP). Residue concentrations in fruit after treatment with 200 ppm IMZ at 50°C were 3.46 ppm, about twice the level (1.80 ppm) found in fruit treated with 1000 ppm IMZ at 19°C. Fungicide degradation rates during storage showed similar patterns resulting in an approximately 50% decrease. Both fungicide treatments significantly reduced decay and chilling injury (CI) during storage and SMP. Hot water reduced CI and decay but not as effectively as the IMZ treatments. Soluble solids concentrations were not affected by treatments, IMZ treatments resulted in significantly lower values of titratable acidity and higher concentrations of ethanol in the juice after SMP. Weight loss was significantly higher in fruit dipped in water at 50°C after SMP. No visible damage occurred to the fruit as a result of any of the treatments.

Benomyl sensitivity of isolates of Colletotrichum acutatum and C. gloeosporioides from citrus

Postbloom fruit drop (PFD) of citrus, caused by Colletotrichum acutatum, produces orange-brown lesions on petals and results in premature fruit drop and the retention of calyces. C. gloeosporioides is common in groves and causes postharvest anthracnose on fruit. Both diseases are controlled effectively by the fungicide benomyl in research fields and commercial orchards. Highly sensitive and resistant isolates of C. gloeosporioides were found, whereas all isolates of C. acutatum tested were moderately resistant. In preliminary studies conducted in vitro with three isolates of each, mycelial growth of sensitive isolates of C. gloeosporioides was inhibited completely by benomyl (Benlate 50 WP) at 1.0 μg/ml, whereas resistant isolates grew well at 10 μg/ml. Growth of all isolates of C. acutatum was inhibited by about 55% at 0.1 μg/ml and by 80% at 1.0 μg/ml. Spore germination of C. acutatum was inhibited more at 0.1 μg/ml than at 1.0 μg/ml or higher concentrations. In all, 20 isolates of C. acutatum from 17 groves and 20 isolates of C. gloeosporioides from 7 groves were collected from locations with different histories of benomyl usage in São Paulo, Brazil, and Florida, United States. Benomyl at 1.0 μ.g/ml completely inhibited growth of 133 isolates of C. gloeosporioides, with the exception of 7 isolates that were highly resistant to the fungicide, whereas all isolates of C. acutatum were only partially inhibited at 0.1 and 1.0 μg/ml. Analysis of variance indicated that the sensitivity of the isolates of C. acutatum was not affected by benomyl usage or grove of origin, and country of origin had only minor effects. No highly resistant or sensitive isolate of C. acutatum was recovered. Partial sequencing of the β-tubulin gene did not reveal nucleotide substitutions in codons 198 or 200 in C. acutatum that usually are associated with benomyl resistance in other fungi.

Use of modified atmosphere to extend shelf life of fresh-cut carambola (Averrhoa carambola L. cv. Fwang Tung)

Fresh-cut fruit products, including carambola (Averrhoa carambola L.) have limited marketability due to cut surface browning attributed to oxidation of phenolic compounds by enzymes such as polyphenol oxidase (PPO). The objective of this study was to evaluate postharvest changes of carambola slices in three different packagings. Carambola fruit (cv. Fwang Tung) were picked from the orchard of Estação Experimental de Citricultura de Bebedouro at mature-green stage. Fruit were washed, dipped in NaOCl solution (200 mg.L -1 for 5 minutes), and stored overnight at 10°C. Fruit were manually sliced into pieces of approximately 1 cm. Slices were rinsed with NaOCl solution at 20 mg.L-1, drained for 3 minutes, and packaged in polyethylene terephthalate (PET) trays (Neoform N94); polystyrene trays covered with PVC 0.017 mm (Vitafilm - Goodyear); and vacuum sealed polyolefin bags (PLO, Cryovac PD900). The packages were stored at 6.8°C and 90%RH for 12 days and samples taken every 4 days. PET trays and PVC film did not significantly modify internal atmosphere and the high water permeability of PVC led to more rapid slice desiccation. PPO activity was lower when slices were packaged in PLO vacuum sealed bags, which reduced discolouration and led to better appearance maintenance for up to 12 days.

Utilização de água residuária do processo pós-colheita do café na produção de mudas de cafeeiro

Intending to achieve better results on coffee production, the coffee producers began, since the 80s, to process the coffee postharvest, in order to ensure product's superior quality. However, with the processing, other problem appeared, the contamination of rivers, creeks, soil and water table from coffee wastewater (ARC). This paper had as main objective to use the ARC on the coffee plants' production verifying its viability and if the ARC is able to supply the coffee potassium requirements when they don't receive potassium chloride in the organic compound. The work was developed at Faculdade de Ciências Agronômicas - UNESP, Botucatu-SP, in a greenhouse located at Departamento de Engenharia Rural. The work consisted of 10 treatments on a 5×2 factorial (5 wastewater proportions of coffee after the harvest processing - 0%, 25%, 50%, 75% and 100% - and potassium chloride presence or absence in the composition), with 4 repetitions with a completely randomized statistical design. The ARC was applied each 48 hours in an irrigation depth of 10 mm. After 6 months, the plants' vegetative characteristic had been evaluated as well the chemical characteristics of the compound and of the plants. We observed that the treatments with potassium chloride presence showed worse vegetative characteristics compared with treatments which did not have KCl in its composition. Moreover, with the increase of the wastewater dosage, it happened a decrease in the vegetative characteristics, however an addition in the chemical characteristics of the compound. Also, the treatments without KCl presence and with 0% and 25% of coffee wastewater had been statistically equal, showing the viability in the use of the ARC in the production of coffee plants, since the compound does not contain KCl and that the water used in the composition is a mixture of 25% of ARC with 75% of common water.

Effect of different pulse treatments on vase life of inflorescences of oncidium varicosum 'Samurai'

Oncidium varicosum is a species of orchid that is prevalent in South America. This species produces yellow flowers, which are commonly named golden shower, ballet dancer and Anita's flower. The study of the post-harvest physiology of flowers involves examination of factors related to quality loss of cut flowers, which is related not only to several physiological processes but also to interactions between the floral components and qualitative factors. In this context, our research involved the study of physiological aspects of the post-harvest physiology of cut inflorescences of Oncidium varicosum ('Samurai') after treatment with pulsing solutions containing silver salts, 8-HQC and sucrose. A reduction of relative water content of Oncidium flowers treated with pulsing STS (2 mM) was observed. The soluble carbohydrates and reducing sugars content decreased, and higher contents were measured in flowers treated with STS (2 mM). All parameters related to flower coloration were reduced in all treatments. Similar results were obtained for carotenoid content, except for the STS treatment (2 mM), which differed significantly from the other treatments on the 8th and 12th days of vase life. The inflorescences' longevity varied from 12 days (distilled water) to 15 days (STS 2 mM).

Controle em pós-colheita de Penicillium digitatum em laranja-pera com microrganismos e tratamento térmico

The consumer market demands food without pesticide residues. Therefore, this study focused on evaluating the control of green mold in Pera orange trees with biocontrol agents (Bacillus subtilis, Bacillus licheniformis and Bacillus subtilis (QST 713)), associated or not with heat treatment. The fruit was obtained in packinghouse before processing, being washed and disinfected with the use of Sodium Hypochlorite. Fruits submitted to these treatments were stored from 11 to 28 days at temperature of 10 °C and RH 90%±5 or for eight days at 20 °C and 90%±5. In general, the heat treatment reduced the disease severity determine by the area under the disease progress curve in the fruit and the incidence of natural postharvest disease in Pera oranges. On the other hand, biocontrol agents did not control the disease, showing that the organisms tested did not present curative activity against the green mold.

Avaliação de microrganismos antagônicos, Saccharomyces cerevisiae e Bacillus subtilis para o controle de Penicillium Digitatum

Citrus fruits are affected by diverse diseases, mainly the fungal infections, which affect productivity and quality, especially when it targets the market of fresh fruit. Among the fungal diseases that occur in postharvest, there is the green mold caused by Penicillium digitatum. The control measures are based mainly in the treatment of fruits with different combinations of fungicides in packing-house. Due to restrictions on the presence of residues of fungicides in citrus fruits and the increasing development of resistant strains of pathogens to the fungicide used, it is necessary to search for control alternatives such as biological control. Therefore, this study aimed to: (i) verify the antagonistic effect of biological control agents (BCA), being 13 isolates of Bacillus subtilis and 06 isolates of Saccharomyces cerevisiae against P. digitatum, (ii) study in vitro interactions between pathogen and BCA (iii) determine the effect of integration of antagonists with sodium bicarbonate and carnauba wax in the control of green mold. The results showed that the majority of the isolates, and all yeast isolates inhibited the mycelial growth of the phytopathogen. Only one isolate of B. subtilis (ACB-84) was able to inhibit the germination of P. digitatum (72% of inhibition), whereas ACB-K1 and ACB-CR1 (S. cerevisiae) were the most effective with inhibition from 78 and 85.7% respectively. The addition of sucrose (0.5%) favored the inhibition of conidia germination by the yeast isolates. The results from the in vivo control showed the viability of S. cerevisiae ACB-K1 and ACB-CR1 to control P. digitatum in 'Tahiti' lime fruits and orange 'Hamlin' fruits, respectively. The combination of sodium bicarbonate and biocontrol agents did not result in improvements in the curative control of the green mold. Carnauba wax (18% of TSS) favored the antagonistic activity of S. cerevisiae, and this effect depended on the variety of fruits in the study and of the yeast isolate used for the biocontrol.

Multiple ornamental uses of Costus stenophyllus standi. & L.O. Williams

Costus stenophyllus or bamboo costus, despite its high ornamental potential, is still little known in the cut flower and ornamental plant market. The bamboo costus is a spiral ginger admired for its beautiful stems that are lined with brown colored alternating bands. This costus has rather straight and upright stems. Conical red inflorescences, which resemble the head of a snake, emerge from the base of the plants. The flowers are light yellow and emerge between the red scales on the rather long-lasting, attractive inflorescences. This study was carried out to evaluate the possibility of using these species as a garden plant, cut flower and cut stem. Thus, the characterization was made based on 28 characters of the plant, the leaves, the flower stem, the flowers, as well as season blooming characteristics and flower postharvest longevity.

Polyphenoloxidase activity in peaches after vibration

The vibration during transportation is one of the main causes of fruit damage. The actual methodologies used for damage evaluation in fruits seem to be subjective, since most of them are based on visual evaluation. In this study the effect of vibration, for one and two hours, on polyphenoloxidase (PPO) activity in peach pulp was investigated. The relation among PPO activity variation, postharvest time and resting time were also considered. Results showed that vibration affects PPO activity. However, it was not possible to correlate PPO activity variation and vibration.

Lâminas de irrigação e cobertura do solo na produção e qualidade de frutos da gravioleira

The crop of soursop has been known for presenting great potential for the domestic market and good prospects for export. In this context, an experiment was conducted in the municipality of Remigio in the state of Paraiba, in order to evaluate the effects of irrigation depths applied weekly on the productive behavior and postharvest quality of fruits of soursop 'Morada' in the soil with and without mulching with crop residues. Treatments were arranged in randomized blocks with three replications and three plants per plot, using a factorial arrangement 5×2, referring to the soil with and without mulching with crop residues, and five irrigation depths of 0, 4.3, 8.6, 12.9 and 17.2 mm plant1. Irrigation was performed manually, once a week from September 2008 to March 2009. The presence of mulch on the soil and increasing depths of irrigation elevated the values of mean mass, production per plant and yield of soursop 'Morada', and decreased the levels of soluble solids.

Storage of sugarcane stalks (Saccharum officinarum cv. SP 79-1011) in low oxygen atmospheres and the effects on enzymatic browning

Although sugarcane consumption is very popular worldwide there are few studies regarding the postharvest storage of stalks that focus on controlling enzymatic browning. The objective of this study was to evaluate the quality of sugarcane stalks stored at 10±1°C in controlled atmosphere with various oxygen (O2) levels (1kPa, 5kPa, 10kPa, 15kPa, and 21kPa) and to verify the effect of this storage on the activities of polyphenoloxidase (PPO) and peroxidase (POD). At 1kPa and 5kPa O2, the stalks' respiratory rate, POD activity, and reducing sugar content were significantly less (P<0.05) than at higher O2 concentrations. In contrast, low O2 levels did not affect PPO activity or influence cane coloration. These results can be used to guide the choice of plastic films, making it possible to store sugarcane stalks in a controlled atmosphere. © 2013 Elsevier B.V.

Conservação pós-colheita de atemóia cv. Thompson

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Isolamento, purificação e caracterização da peroxidase de yacon (Smallanthus sonchifolius)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Conservação refrigerada de uva Itália com utilização da irradiação e atmosfera modificada

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)