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Passos J.L.,Federal University of Viçosa | Barbosa L.C.A.,Federal University of Viçosa | Demuner A.J.,Federal University of Viçosa | Barreto R.W.,6570 000 Vicosa MG | And 2 more authors.
Planta Daninha | Year: 2010

The present study combines the examination of toxins produced by C. cassiicola and the effects of the fungus colonization on L. camara. C. cassiicola was cultivated on solid media and the crude extracts CAE and CE were produced. Both extracts were submitted to a seed germination and growth assay utilizing Physalis ixocarpa, Trifolium alexandrinum, Lolium multiflorum and Amaranthus hypochodriacus. The effect of the extracts on the ATP-synthesis in isolated spinach chloroplasts was also tested. Bioassay guided chromatographic fractionation identified the most active extract (CAE). From this extract ergosta-4,6,8(14),22-tetraen-3-one (C1) and fatty acids were isolated. The C1 compound reduce ATP synthesis in isolated spinach chloroplasts. The interference of fatty acids with ATP synthesis and also with weed growth provides one explanation of the phytogrowth-inhibitory properties of such fungal extracts. Histological observations involving fungus-plant interaction were made on L. camara plants inoculated with C. cassiicola conidia suspension. After inoculations, fragments of the leaf blades were prepared for observation by light and scanning electron microscopy. Fungal colonization of Lantana camara was typical of a necrotroph and penetration initiated a hypersensitive response. L. camara reacted to the pathogen penetration through thickening of the epidermis walls, cytoplasm granulation and a cicatrisation tissue.

Fiorini V.A.C.,Federal Rural University of Rio de Janeiro | da Silva D.J.H.,6570 000 Vicosa MG | Mizubuti E.S.G.,6570 000 Vicosa MG | de Barros J.S.,6570 000 Vicosa MG | And 3 more authors.
Horticultura Brasileira | Year: 2010

In this research we evaluated tomato lines for resistance to late blight. An amount of 72 genotypes (70 tomato lines F8 plus the accesses of BGH-UFV '184'and '1497') was evaluated. The lines were derived from interspecific crossing between Solanum lycopersicum ('Santa Clara') and Solanum habrochaites f. glabratum (access BGH-UFV '6902'). The experiments were conducted in field in the randomized blocks design with two and three replications in the first and second experiment, respectively. The plants were inoculated with a sporangia blend of Phytophthora infestans from the six different tomato producing cities of Zona da Mata, Minas Gerais State, Brazil, in a concentration of 103 sporangia mL-1. We evaluated the percentage of disease severity, presented as an area under the disease progress curve (AUDPC). In both experiments 10 tomato lines plus the access BGH-UFV '1497' were selected. The lines identified as 50 I, 90 J, 127 F, 145 B and 164 G presented medium values of AUDPC inferior to the resistant witness. It was possible the introgression of late blight resistance genes present in S. habrochaites f. glabratum in S. lycopersicum.

Costa F.B.,Ufcg Unid Academy Tecnol Alimentos | Duarte P.S.,6570 000 Vicosa MG | Puschmann R.,6570 000 Vicosa MG | Finger F.L.,UFV Depto Fitotecnia
Horticultura Brasileira | Year: 2011

The aim of this work was to study the physical, chemical, physiological and microbiological changes during the flow chart of fresh-cut strawberry. Strawberry cvs. Camarosa, Dover and Tudla, derived from experimental area of the Universidade Federal de Viçosa, were selected by color (red 3/4) and absence of wound. Afterwards, the minimal processing was evaluated, as follows: fast cooling, water and ice, removal of the calyx followed by conservation at 5±0.5°C and 90-95% RH for 13 days, sanitation, drainage, cut in halves. Removal of the calyx did not result significant difference for fresh weight, total soluble solids, total titratable acidity, pH and ratio TSS/TTA. The rapid cooling resulted in lower electrolyte leakage and respiratory rate, especially sanitized fruits. Sanitization by immersion in chlorine solution slowed the growth of fungi and yeast. Drainage for 20 minutes eliminated practically all water on the surface of the fruits. The fresh-cutting did not affect the visual and nutritional quality of strawberries like appearance, microbiot, vitamin C, anthocyanins and phenolic compounds, consisting of alternative market potential economically viable.

Pereira F.H.F.,Federal University of Campina Grande | Puiatti M.,6570 000 Vicosa MG | Finger F.L.,6570 000 Vicosa MG | Cecon P.R.,6570 000 Vicosa MG
Horticultura Brasileira | Year: 2011

In this experiment we evaluated the growth, partition of assimilates and yield of melons type hybrid Charenthais 'Fleuron' under different shading nets. The experiment was conducted at Federal University of Viçosa, from November 24, 2003 to March 11, 2004. The treatments consisted of four growth environmental conditions, as follows: control (full sun), and under Aluminet® 30%-O, Cromatinet® 30%-O, Sombrite® 30%, with reduction of photosynthetic active radiation (PAR) of 30.85%, 35.9% and 32.0%, respectively. The experiment was arranged in a complete random design with four replicates. For the periodically evaluated characteristics we used a sub divided parcel 4 x 7 with the growing conditions in the parcel and the evaluations on the sub parcel (0, 14, 28, 42, 56, 70 and 84 days after transplantation). Among the shading nets, overall growth was superior under Aluminet® 30%-O, with similar plant height, length and number of internodes, number of leaves per plant, leaf dry weight, total and commercial yield of fruits and greater leaf area per plant compared to control at full sun. The low number of daily radiation (4.47 hours) and the good growth and yield of the melon when shaded by 30.85% with Aluminet® 30%-O, are indicatives that this culture does not require elevated levels of radiation as mentioned before. The growth of melon under partial restriction of light is promising, opening opportunities to production in new environments as agroforestry systems and associated cultivations.

Simoes A.N.,Federal Rural University of Pernambuco | Moreira S.I.,6570 000 Vicosa MG | da Costa F.B.,6570 000 Vicosa MG | de Almeida A.R.,UFV Depto Fitotecnia | And 2 more authors.
Horticultura Brasileira | Year: 2010

The quality of baby carrots may be associated to the standard of the raw material that in turn, may be influenced by agronomic practices. Thus, the effect of planting density and harvest age were assessed on physical and morphological characteristics, yield and end quality of intact and minimally processed carrots in the form of baby carrots. A randomized block experimental design was used with the density in the plots (4 × 20 cm and 4 × 7.5 cm) and the harvest age in the subplots (50, 57, 64, 71, 78, 85, 92, 99 and 106 days), with five replications. The experimental unit consisted of 25 plants. The assessments of diameter, length, yield, secondary phloem translocation with the cambio and total carotenoids were decisive in selecting the carrot harvest age for baby carrot manufacture. Under the 4 × 20 cm and 4 × 7.5 cm adensed conditions, harvested between 85 and 92 days, carrot roots became thinner and more orange in color (with maximum carotenoid accumulation), larger and with satisfactory yields and therefore more acceptable for minimal processing in the form of baby carrots. Thus the decision of populational density associated to harvest age will depend on the market demand, on price, quality and other variables. The use of adensed cropping with early harvests may lead to obtain carrots and respective baby carrots that are more acceptable for commercialization.

do Simoes N.A.,Ufrpe Unid Academy Serra Talhada | Puiatti M.,UFV Depto.Fitotecnia | Salomao L.C.C.,UFV Depto.Fitotecnia | Mosquim P.R.,6570 000 Vicosa MG | Puschmann R.,6570 000 Vicosa MG
Horticultura Brasileira | Year: 2010

The storage of minimally processed vegetables at low temperatures, in association with proper packaging, represents one of the available technological solutions to mitigate the variations that hinder the quality of final products during storage. We studied the physicochemical variations that occur straight after minimal processing, as well as those that occur during the storage of minimally processed and intact leaves of collard greens (Brassica oleracea var. acephala), stored in 50-μm thick polypropylene bags, with 810-μm diameter perforations. Leaves were stored for 15 and 9 days, at 5 and 10±1°C, respectively. There were losses of total chlorophyll, soluble sugars, starch, and soluble amino acids immediately after the minimal processing. The rates of degradation and/or use of chlorophyll, ascorbic acid, soluble sugars, and starch during storage were similar on minimally processed and intact leaves, independently of the storage temperature. On contrary, fresh mass loss was almost two fold larger in minimally processed leaves after nine days of storage, regardless of temperature. We also observed a transient increase in the content of soluble amino acids at the end of storage in minimally processed leaves. The increase in the storage temperature to 10°C enhanced the chemical variations both in minimally processed and intact leaves. As consequence, the rates of degradation and/or use of chlorophyll, ascorbic acid, sugars and starch mounted, and the accumulation of soluble amino acids was stimulated. We concluded that it is necessary to keep on searching for alternative packaging for minimally processed collard greens, and to associate it with storage at low temperatures, but mimicking distribution and commercialization conditions of the cold-chain. Thus, we can succeed in adequately reducing the physicochemical variations that induce quality losses in minimally processed vegetables.

Gomes D.P.,6570 000 Vicosa MG | da Silva A.F.,6570 000 Vicosa MG | Dias D.C.F.S.,6570 000 Vicosa MG | Alvarenga E.M.,6570 000 Vicosa MG | And 2 more authors.
Horticultura Brasileira | Year: 2012

We evaluated the effect of the priming with polyethyleneglicol (PEG) 6000 followed or not of drying on two lots of eggplant seeds with medium and low vigor respectively. The seeds were submitted to the treatments of priming with PEG 6000 in the osmotic potentials of -0.6, -0.9 and -1.2 MPa during 48 or 96 hours of priming with and without subsequent drying. For the soaking of seeds in osmotic solutions, these were placed over three sheets of paper boxes such germitest gerbox conditioning moistened with each solution in a 3:1 ratio. The control group was represented by unprimed seeds. The priming for both lots provided higher values in relation to the vigor through the first counting of germination, seedlings and primary root length, germination and emergence rates, emergence and dry weight of seedlings when compared to the non-primed seeds. These results were not verified for germination; significant differences practically were not observed in relation to the controls. Improvements in relation to the vigour were not higher on lot 2 than those obtained on lot 1. The priming with PEG 6000 with subsequent drying increased the vigor of eggplant seeds of the cultivar Morro Grande in relation to those non-primed, however, without differences in the germination.

Muniz M.A.,6570 000 Vicosa MG | Barbosa J.G.,6570 000 Vicosa MG | Garde G.P.,6570 000 Vicosa MG | Alves C.M.L.,6570 000 Vicosa MG
Horticultura Brasileira | Year: 2013

The cultivation of gerbera is spread all over the country, but little information is available about nutritional requirements for this crop. In order to evaluate the effect of potassium and harvesting times for gerbera during the year, an experiment was carried out in a greenhouse with the cultivar Dinamyte in a completely-randomized split-plot design. The plots consisted of five doses of potassium (0, 2, 4, 6 and 12 g/plant/year) and the sub-plots were seven harvesting times of inflorescences (12, 15, 19, 23, 25, 28 and 31 weeks after the beginning of the treatment) with five replications. At harvest we evaluated length, diameter, fresh weight and longevity of the inflorescence and concentration of nutrients in leaf tissue. A significant interaction was observed between rates of potassium and harvest seasons for length of stem, fresh weight and diameter of inflorescence, and 6 g potassium/ plant/year provided the best inflorescence diameter, length and fresh weight of stem in weeks 25 and 31. The highest longevity was obtained with 7.8 g of potassium/plant/year and highest production of stems classified as extra was obtained with 7.1 g potassium/plant/ year. The best quality of flower's stem was obtained with a dose of 6 g/plant/year and the quality of the flowers was variable during the year without influence of the rates of potassium on the concentration of the other nutrients.

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