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Search Results: 1 - 10 of 11971 matches for " Ivan Herman Fischer "
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Damage Caused by Psyllids and Influence of Climatic Factors in Brazilian Accesses of Guava Trees Cultivated in Organic System  [PDF]
Juliana Altafin Galli, Marcos Doniseti Michelotto, Maria Beatriz Bernardes Soares, Ant?nio Lucio Melo Martins, Ivan Herman Fischer
American Journal of Plant Sciences (AJPS) , 2014, DOI: 10.4236/ajps.2014.510158
Abstract:

The psyllid (Triozoida sp.) is the primary pest of guava tree in the Central Northern region of S?o Paulo State, Brazil. The variation of climatic factors may influence directly or indirectly the behavior of agricultural pests. The present work had objectives to evaluate the damages caused by psyllid in accesses of guava trees in order to identify materials with potential resistance to pest and the possible correlations of the damage with the meteorological factors, in an orchard of guava conducted in an organic system. Eighty-five guava accesses were evaluated. Each one was analyzed at random 10 leaves containing the symptom of the psyllid attack, through visual range of notes. The averages of the notes were compared by Scott-Knott test at 5% probability. The 25 accesses with the highest average damage of psyllid had the data submitted to correlation (Pearson), with the minimum and maximum temperature (°C), precipitation (mm) and relative humidity (%). Guava accesses used commercially were the most susceptible to the attack of psyllid, compared to the selections, with an emphasis to access “L4P14”, “L7P28” and “L8P32B”, which were the least attacked. The study of correlation between psyllid damages and meteorological factors, must be used the medium temperature, relative humidity and rainfall accumulated in the period of 14 days before the evaluations. There is a positive correlation between minimum temperasture, precipitation and relative humidity with the damage of psyllids in leaves of guava.

Desenvolvimento, produtividade e sobrevivência de maracujazeiro-amarelo enxertado e cultivado em área com histórico de morte prematura de plantas
Cavichioli, José Carlos;Corrêa, Luiz de Souza;Garcia, Maria José de Marchi;Fischer, Ivan Herman;
Revista Brasileira de Fruticultura , 2011, DOI: 10.1590/S0100-29452011005000075
Abstract: the objective of this study was to evaluate the vegetative growth, yield and survival of yellow passion fruit (passiflora edulis sims) grafted on the three rootstocks in area with description of premature death of plants. the experiment was carried out in adamantina, sp, brazil, from may 2006 to february 2007, adopting the statistical design of randomized blocks, with three treatments and seven replications. the rootstocks evaluated were passiflora edulis, p. alata and p. gibertii, using conventional cleft grafting. the variables evaluated were: stem diameter of the rootstocks, stem diameter of the grafts, length of internodes, length of the secondary branches, number of tertiary branches, number of fruits, average weight of fruits, diameter and length of fruits, yield and plant survival. the work demonstrated that the use of the grafting in yellow passion fruit is a viable option as vegetative propagation, as well as a means of controlling some soil pathogens, one problem that has limited the expansion of culture. it was observed that plants grafted on p. edulis presented better initial vegetative growth, followed of p. gibertii and of p. alata. the lowest yield was obtained in p. alata. it was observed that although the presence of fusarium solani and rotylenchulus reniformis in soil, 91% of the plants grafted on p. gibertii survival after 12 months of field planting, whereas in p. alata and p. edulis these indices were 60% and 8.6%, respectively, showing a bigger tolerance to the root diseases.
Citrus postharvest diseases and injuries related to impact on packing lines
Fischer, Ivan Herman;Ferreira, Marcos David;Spósito, Marcel Bellato;Amorim, Lilian;
Scientia Agricola , 2009, DOI: 10.1590/S0103-90162009000200010
Abstract: brazilian exports of fresh citrus represent less than 1% of the overall brazilian production. phytosanitary barriers and poor appearance stand out among the several reasons contributing to such low exporting/production ratio. the purpose of this work was to characterize postharvest injuries in 'valencia' sweet oranges and 'murcott' tangors produced for foreign markets after different processing stages in a packinghouse, as well as to identify critical points and impact extent on packing lines. sampling was performed both after pre-washing and degreening the fruits, and also at the arrival on the packing table and in the pallet. they were stored for 21 days at 25oc and 85% rh. the incidence of injuries was visually assessed every three days. an instrumented sphere with acceleration register was used to evaluate the extent of impacts (g, m/s2) at the 19 transference points of the citrus processing line. there was low rot incidence (under 3.5%) at the different stages of fruit processing, with slight increase after degreening in 'valencia' orange and a decrease after fungicides treatment in 'murcott' tangor. the main pathogens found in the oranges were lasiodiplodia theobromae and penicillium digitatum, which were surpassed by colletotrichum gloeosporioides in the tangors. impacts in the processing line were caused mainly by drops on hard surfaces, with 94.7% of them varying from 30 to 95 g. the greatest impacts were observed when fruits were transferred from the processing line to bins destined to degreening. mechanical injuries related to oleocellosis increased until the arrival of fruits at the packing table.
Produ??o de enzimas extracelulares por Fusarium solani de maracujazeiro amarelo
Bueno, César Júnior;Fischer, Ivan Herman;Rosa, Daniel Dias;Furtado, Edson Luiz;
Tropical Plant Pathology , 2009, DOI: 10.1590/S1982-56762009000500009
Abstract: in most brazilian producer states, one of the main diseases of the passion fruit is collar rot caused by fusarium solani. little is known about the physiology of this pathogen from yellow passion fruit, which mainly involves the production of extracellular enzymes. the objective of this work was to verify, in individual and appropriate culture media, the production of the extracellular enzymes amylase, lipase, cellulase, proteases (caseinase and gelatinase), lacase (oxydase) and catalase by isolates of f. solani from yellow passion fruit. the experimental design adopted was an entirely randomized two-factor scheme (nine isolates and seven enzymes) with three repetitions. all the isolates of f. solani produced, in a semi-quantitative manner, the extracellular enzymes amylase, lipase, cellulase, caseinase (protease) and lacase. however, the amount of each enzyme produced was significantly different among the isolates. the extracellular enzymes gelatinase (protease) and catalase were produced in a small amount and in an equal manner by all the isolates of the fungus.
Rea??o de cultivares de batata a Streptomyces scabies, agente causal da sarna comum profunda
Fischer, Ivan Herman;Teixeira, Ana Paula Matoso;Toffano, Leonardo;Garcia, Ely Oliveira;
Summa Phytopathologica , 2009, DOI: 10.1590/S0100-54052009000300010
Abstract: this work aimed to characterize the isolates of streptomyces, responsible for deep common scab symptoms in potato, according to morphological and physiological criteria; to evaluate the resistance of potato cultivars to the disease and the aggressiveness of bacterium isolates. the streptomyces isolates presented gray coloration on yeast extract and malt medium and spiral spore chains, produced on aerial hyphae. production of melanina occurred in tirosine-agar medium and the utilization of eight recommended carbon sources. these properties correspond to the s. scabies species. healthy potato seeds of six cultivars were planted in substratum infested with six isolates of s. scabies separately, and the plants cultivated in plastic bags and under open sky. the scab severity was evaluated with a diagrammatic scale and evaluated the tuber production (g/plant). cvs. mondial and jaete bintje were the most resistant to the common scab with average severity of 10.5% and 14.0%, respectively, followed by cv. asterix (17.4%), agata (21.8%), monalisa (23.0%) and cupido (23.3%). the aggressiveness of the isolates varied quantitatively, with higher severity for the isolate m4 (34.7%) and minor for the isolate m1 (6.2%). reduction of tuber production was verified in cv. jaete bintje in the first experiment, and when the cultivars were infected by isolates a1, m2 and m3 in the first experiment and by isolate m4 in the second experiment.
Potencial do flavedo (epicarpo) de Citrus aurantifolia cv. Tahiti no controle do bolor verde e da antracnose em citros
Toffano, Leonardo;Fischer, Ivan Herman;Blumer, Silvia;Pascholati, Sérgio Florentino;
Summa Phytopathologica , 2012, DOI: 10.1590/S0100-54052012000100010
Abstract: brazil is considered to be the biggest citrus producer and orange juice exporter. post-harvest diseases represent a great loss in the citriculture, and for many fruits to be exported they should be free of chemical residues. in relation to some pathogens of importance in post-harvest, it can be mentioned penicillium digitatum (green-mold) and colletotrichum gloeosporioides (anthracnose). because of the economical importance of these diseases for citric fruits, in terms of compromising quality and control difficulties, the search for alternative control measures that can make possible to improve the producing capacity of the producers and the obtaining of fruits with excellent quality are indispensable. therefore, it was studied the viability of the control of post-harvest diseases in valência orange fruits (citrus sinensis) by using the biotic agents flavedo (citrus auratifolia cv. tahiti), lentinula edodes, agaricus subrufescens (syn. agaricus brasiliensis), albedo (citrus sinensis cv. valência) and the abiotic agent jasmonic acid. it was possible to observe that the aqueous extracts from the flavedo (c. aurantifolia) inhibited the pathogens in valência orange fruits when treated in post-harvest, based upon symptom and sporulation reduction. on the other hand, the albedo (c. sinensis), l. edodes, a. subrufescens and jasmonic acid had no effects on p. digitatum and c. gloeosporioides in the fruits.
Doen as pós-colheita em laranja 'Pêra' produzida em sistema organico econvencional e resistência de Penicillium digitatum a fungicidas Postharvest diseases in 'Pêra' orange cultivated in organic and conventional systems and resistance of Penicillium digitatum to fungicides
Ivan Herman Fischer,Maria Cecília de Arruda Palharini,Marcel Bellato Spósito,Lilian Amorim
Summa Phytopathologica , 2013,
Abstract: As doen as pós-colheita podem ser responsáveis por perdas tiabendazol (10 mg.L-1) e imazalil (1 mg.L-1). Frutos tratados com significativas ao citricultor. Este trabalho objetivou: a) caracterizar imazalil apresentaram a menor incidência (5,4%) de doen as pós-as doen as pós-colheita em laranjas 'Pêra' provenientes de cultivo colheita, enquanto que frutos provenientes de pomares organicos organico e convencional, com ou sem tratamento pós-colheita com apresentaram a maior incidência (25,2%). As principais doen as pósimazalil, comercializadas na CEAGESP; e b) detectar a presen a de colheita foram o bolor verde em frutos produzidos em sistema isolados de Penicillium digitatum resistentes a fungicidas em frutos convencional e as podrid es pedunculares de lasiodiplodia e de com bolor verde. Frutos permaneceram em camara úmida por 24 phomopsis em frutos organicos. A frequência relativa de isolados de horas, e por mais 13 dias a 25 oC e 85% de UR. A incidência de P. digitatum resistentes ao fungicida tiabendazol foi menor em frutos doen as foi avaliada visualmente a cada 2-3 dias. A presen a de P. organicos, enquanto a frequência de isolados de P. digitatum resistentes digitatum resistente a fungicidas foi avaliada em fun o do crescimento ao imazalil e à mistura tiabendazol+imazalil foi maior em frutos que micelial em meio batata-dextrose-ágar acrescido dos fungicidas receberam tratamento pós-colheita com imazalil. Postharvest diseases may be responsible for significant losses to added of the fungicides thiabendazole (10 mg.L-1) and imazalil (1 citrus growers. This study aimed to: a) characterize the postharvest mg.L-1). Fruits treated with imazalil had lower incidence (5.4%) of diseases in 'Pêra' oranges from organic and conventional crops, with postharvest diseases, while fruits from organic crop had the highest or without postharvest treatment with imazalil, marketed in incidence (25.2%). The main postharvest diseases were green mold CEAGESP; and b) detect the presence of Penicillium digitatum isolates in fruits produced in the conventional system and Lasiodiplodia and resistant to fungicides in fruits with green mold. Fruits were kept in a Phomopsis stem-end rot in organic fruits. The relative frequency of humid chamber for 24 hours and for additional 13 days at 25 oC and P. digitatum isolates resistant to the fungicide thiabendazole was 85% RH. The disease incidence was visually evaluated at every 2-3 lower in organic fruits, while the frequency of P. digitatum isolates days. The presence of P. digitatum resistant to the fungicides was resistant to imaza
Postharvest of yellow passion fruit: effect of chemicals and storage temperature/ Efeito de produtos químicos e temperaturas de armazenamento na pós-colheita de maracujá-amarelo
Maria Cecília Arruda,Ivan Herman Fischer,Elisangela Marques Jeronimo,Michele Moraes Zanette
Semina : Ciências Agrárias , 2011,
Abstract: This study aimed to evaluate the effect of chemicals and storage temperatures on the incidence of diseases and the physicochemical quality of yellow passion fruit. Fruits were harvested with 30% of the skin colored yellow and treated with different products: sodium dichloroisocyanurate (200 mg.L-1 of active chlorine), prochloraz (1000 mg.L-1), control (fruits not treated). Treatments were applied by immersion for three minutes. The fruits were packed in expanded polystyrene trays coated with PVC 17?m and stored at 15 and 25°C, 55% RH for 10 days and analyzed periodically for: rot incidence, skin color, soluble solids, titratable acidity and ascorbic acid content. After five days of storage the visible stem mycelial growth was higher in fruits stored at 25°C than at 15°C. The fungicide prochloraz reduced the appearance of rots after ten days of storage fruit. The main fungal genera found in the stems were Cladosporium, Alternaria and Fusarium. Reduction of acidity was observed on the tenth day of storage, and found lower levels of acidity in fruits at 25°C. Regarding the skin color, reduction in the angle of color during storage indicating yellowing of skin, and the fruits stored at 25°C showed a lower angle of color. The levels of ascorbic acid in fruit decreased approximately 10% during storage. The “ratio” (soluble solids: acidity) increased during storage, being higher in fruits at 25°C, due to lower acidity. It is concluded that prochloraz was effective in controlling rots and that the use of chemicals not influence the physicochemical quality of packaged fruits. Changes of physicochemical characteristics were observed depending on temperature and time of storage. Este trabalho teve como objetivo avaliar o efeito de produtos químicos e de temperaturas de armazenamento na incidência de doen as e na qualidade físico-química de maracujá-amarelo. Frutos colhidos com 30% da superfície da casca amarela foram tratados com diferentes produtos: dicloroisocianurato de sódio (200 mg.L-1 de cloro ativo); procloraz (1000 mg.L-1); controle (frutos sem tratamento). Os tratamentos foram aplicados por imers o durante três minutos. Os frutos foram acondicionados em embalagem de poliestireno expandido revestida por PVC 17μm e armazenados a 15 e 25°C, UR 55%, por um período de 10 dias. Os mesmos foram analisados periodicamente quanto à: incidência de podrid es, cor da casca, sólidos soluvéis totais, acidez titulável e teor de ácido ascórbico. A incidência de podrid es e de crescimento micelial visível no pedúnculo foi crescente conforme o tempo de armazenamento. Após ci
Quality of minimally processed snap bean in function of rinse and sanification operations/ Qualidade de feij o-vagem minimamente processado em fun o das opera es de enxague e sanifica o
José Eduardo Peres,Maria Cecília Arruda,Mirian Souza Fileti,Ivan Herman Fischer
Semina : Ciências Agrárias , 2011,
Abstract: This work had the purpose to evaluate the quality of the minimally processed snap bean in function of rinse and sanification operations. Snap bean cv. Itatiba 2 were selected, cleaned, processed and submitted to the following treatments: T1 – rinse in water only, T2 – rinse in water, followed by immersion in chlorinated solution (100 mg.L-1) for 5 minutes, T3 – immersion in chlorinated solution (100 mg.L-1) for 5 minutes and T4 – without rinse and without immersion in chlorinated solution (control). The minimally processed snap beans were assessed for appearance, color of the section surface and microbiological characteristics. About the color of the section surface, it could be noticed from the ninth day of storage that the snap bean of the Treatment 1 showed less darkening in relation to the other treatments, and also better accepted sensorially. It wasn’t detected Salmonella and neither coliforms at 45°C in any sample of the different treatments. In relation to the total coliform counts, it could be noticed reduction with the sanification (T2 and T3) on the processing day, and, in general, an increase in the coliform counts during the storage. The total bacteria count was > 105 UFC.g-1 in the snap bean of all treatments in the sixth day of storage, except in that one, which the snap beans were rinsed and sanitized. Therefore, this treatment is recommended and guarantee six days of shelf life for minimally processed snap bean, limited by the bacteria growth. Este trabalho teve como objetivo avaliar a qualidade de vagens minimamente processadas em fun o das opera es de enxague e sanifica o. Vagens cv. Itatiba 2 foram selecionadas, higienizadas, processadas e submetidas aos seguintes tratamentos: T1 - enxágue somente em água, T2 - enxágue em água, seguido de imers o em solu o clorada (100 mg.L-1) por 5 minutos, T3 - imers o em solu o clorada (100 mg.L-1) por 5 minutos e T4 - sem enxágue e sem imers o em solu o clorada (controle). As vagens minimamente processadas foram avaliadas quanto à aparência, colora o da superfície de corte e aspectos microbiológicos. Em rela o à colora o da superfície de corte, observou-se a partir do nono dia de armazenamento que as vagens do Tratamento 1 apresentaram menor escurecimento em rela o às dos demais tratamentos, sendo também melhor aceitas sensorialmente. Salmonella e coliformes a 45oC n o foram detectados em nenhuma amostra dos diferentes tratamentos. Em rela o à contagem de coliformes totais observou-se no dia do processamento redu o com a sanifica o (T2 e T3) e em geral, aumento dos coliformes durante
Eficiência de argila silicatada no controle de Xanthomonas axonopodis pv. passiflorae, in vitro e em mudas de maracujazeiro-amarelo
Brancaglione, Priscila;Sampaio, Aloísio Costa;Fischer, Ivan Herman;Almeida, Aparecida Marques de;Fumis, Terezinha de Fátima;
Revista Brasileira de Fruticultura , 2009, DOI: 10.1590/S0100-29452009000300014
Abstract: the bacterial spot in yellow passion fruit plants, caused by the bacteria xanthomonas axonopodis pv. passiflorae, occurs in all producing areas of the country, and is responsible for great economic losses in the culture of passion fruit. this study aimed to test the efficiency of the silicate clay in the inhibition of the bacteria xanthomonas axonopodis pv. passiflorae in vitro, and in both preventive and curative control of the bacterial spot in seedlings of yellow passion fruit plants. the silicate clay was added to the growth medium at concentrations of: 0.5, 1.0, 1.5 and 2.0%, placed in petri dishes. after the culture medium was cooler, the bacterial suspension was inoculates (107 ufc.ml-1) with a handle, and left incubating at 28 ° c for three days, and then the bacterial growth was evaluated. subsequently, the product at the same concentrations above was sprayed on seedlings of 'afruvec' passion fruit, as preventive or curative. the inoculation of the bacteria was made by foliar spraying of bacterial suspension (107 ufc.ml-1), 24 hours before or after the curative and preventive treatments, respectively. the severity of the disease was measured comparing each four true leaves from bottom up, with a diagrammatic scale. in the concentrations evaluated, the silicate clay inhibited both bacteria in vitro and symptoms of bacterial spot in the curative treatment. in preventive treatment, significant results were obtained using more than 1.0% of clay silicates. based on these results, the clay silicate can be recommended, the concentration of 1.0-2.0% for the control of bacterial spot of passion fruit plants, in foliar sprays.
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