Aline José Maia

Efeito do extrato de alho na quebra de dormência de gemas de videiras e no controle in vitro do agente causal da antracnose (Elsinoe ampelina Shear)

Considering the reduction or elimination of synthetic compounds used in sustainable fruit production systems, this work aimed to search for new alternatives for bud break dormancy and diseases control in grapevines. Single-bud cuttings of grapevines were sprayed with the following treatments: 1) control, 2) 1% SO (soybean oil), 3) 3% GE (garlic extract), 4) 3% GE + 1% SO. After that, the cuttings were kept in a growth chamber (25±2.5oC) for 56 days. The unique treatment that stimulated sprouting of grapevines cv. Isabel Precoce was 3% GE + 1% S), that reached 35% sprouting, differing statistically from the control (12.5%), 1% SO (17.5%) and 3% GE (15.0%). Probably, the stage of deep endodormancy of buds, after only 90 chilling hours (< 7.0oC), avoided better results of bud breaks treatments. Three experiments were carried out in vitro, with different garlic extract doses aiming to evaluate the control of the fungus Elsinoe ampelina. In all trials, there were quadratic effects on mycelial growth, without differences between garlic extract treatments, evidencing its fungicide effect, even for the lowest dose of 0.0615% GE.

Extrato de alho e óleo vegetal no controle do míldio da videira

O objetivo deste trabalho foi verificar o efeito do extrato de alho e do oleo vegetal no controle do mildio da videira cv. Isabel (Vitis labrusca). A severidade da doenca, expressa pela area abaixo da curva de progresso da doenca (AACPD), e a germinacao de esporângios de seu agente causal Plasmopara viticola foram as variaveis avaliadas. Os tratamentos consistiram em 0; 5; 10; 15; 20; 25 ou 30 mL L-1 de extrato de alho adicionados de 2,5 mL L-1 oleo vegetal, calda bordalesa (1:1:100) e testemunha (sem tratamento). No teste de germinacao, utilizou-se mancozebe (2 g L-1) como tratamento-padrao. Em condicoes de campo, observou-se reducao da severidade do mildio com o oleo vegetal, sendo que o extrato de alho, a partir de 20 mL L-1, potencializou tal acao biocida. A germinacao dos esporângios de P. viticola variou em funcao do tempo de exposicao ao extrato de alho, nao apresentando boa eficiencia quando comparada ao tratamento com calda bordalesa e mancozebe. O oleo vegetal nao influenciou na germinacao dos esporângios desse patogeno.

Chitosan action on Plasmopara viticola and Elsinoe ampelina development in vitro and in grapevines cv. Isabel

This work aimed to evaluate the effect of chitosan on the control of fungi Elsinoe ampelina and Plasmopara viticola, the causal agents of downy mildew and anthracnose in grapevines, respectively. The concentrations of 0, 20, 40, 80 and 160 mg L-1 chitosan were used in the following trials: mycelial growth, spore germination, and experiment in field conditions. For the last two trials standard treatments with mancozeb and bordeax mixture were added. There was a reduction in E. ampelina mycelial growth and the highest chitosan concentration (160 mg L-1) decreased by 57% the fungus development at 192 hours after incubation. In the germination tests, the concentration of 160 mg L-1 chitosan reduced spore germination in E. ampelina by approximately 98% and P. viticola by 60%, not differing from the treatments with bordeaux mixture and mancozeb. In the field trial the highest chitosan concentrations (80 and 160 mg L-1) decreased anthracnose severity between 93 and 81%. For downy mildew, the concentration of 160 mg L-1 decreased the disease by approximately 81%. Based on these results, chitosan has a great potential for the control of downy mildew and anthracnose in grapevines.

Development of Forestry Species Inoculated with Trichoderma spp. Fertilized with Rock Phosphate

The study aimed to determine the effects of inoculation of Trichoderma spp. on the development and extraction of nutrients from Eugenia pyriformis Cambess. (uvaieira) and Myrcianthes punges (O.Berg.) (guabiju) subjected to fertilization with rock phosphate. The treatments used at planting were: Control; Trichonat PM; Trichoderma sp. FS1; Rock phosphate; Trichonat PM + Rock phosphate; and Trichoderma sp. FS1 + Rock Phosphate. The following characteristics were evaluated at 540 days after planting: plant height, crown diameter, branch insertion points, biomass, and nutrient content. The uvaieiras inoculated with Trichonat PM and Thrichoderma spp. showed higher vegetative growth and higher values of N, P, K, Ca, Mg and S, respectively. For guabijuzeiros, the treatment with Trichoderma spp. presented the highest insertion point of the branches without phosphorus fertilization However, the treatments did not affect nutrient extraction. Thus, Trichoderma spp. inoculants have the potential to promote vegetative growth and nutrient extraction in plants.

Antimicrobial activity of Agaricus brasiliensis on Plasmopara viticola and its effect on the induction of resistance to the control of downy mildew on ‘Isabel Precoce’

Arq. Inst. Biol., v.85, 1-8, e0052017, 2018 RESUMO: Agaricus brasiliensis possui compostos bioativos que apresentam atividade antimicrobiana e induz mecanismos de defesa em plantas contra patógenos. O objetivo deste trabalho foi avaliar a aplicação da suspensão miceliada aquosa de A. brasiliensis no controle do míldio (Plasmopara viticola) e indução de resistência em videi‐ ras Isabel Precoce. Os tratamentos foram: 0, 1, 5, 10, 15 e 20% da suspensão miceliada aquosa de A. brasiliensis, além do tratamento com acibenzolar‐S‐metil. As variáveis analisadas foram: germinação de esporangiósporos; severidade da doença, representada pela área abaixo da curva de progresso da doença; atividade da enzima cata‐ lase; peroxidase e polifenoloxidase. As doses 10, 15 e 20% de sus‐ pensão miceliada aquosa de A. brasiliensis proporcionaram redução de aproximadamente 80% na germinação dos esporangiósporos de P. viticola. Os tratamentos não apresentaram efeitos significativos na redução da área abaixo da curva de progresso da doença do míl‐ dio e na atividade da enzima polifenoloxidase. A dose de 10% da suspensão miceliada aquosa de A. brasiliensis reduziu a atividade de catalase e induziu a atividade da peroxidase. A suspensão miceliada aquosa de A. brasiliensis apresentou efeito fungitóxico na germina‐ ção de esporangióporos, entretanto não foi suficiente para reduzir a severidade do míldio da videira Isabel Precoce, mesmo atuando na atividade das enzimas catalase e peroxidase. Assim, experimen‐ tos deverão ser realizados para verificar a viabilidade das estruturas reprodutivas do patógeno exteriorizadas nas videiras quando trata‐ das com suspensão miceliada aquosa de A. brasiliensis.

Indução da brotação de gemas de macieiras com aplicação de óleos vegetais e mineral

Objetivou-se determinar a eficiencia de oleos vegetais, em mistura com oleo mineral, na inducao da brotacao, na atividade das enzimas catalase e peroxidase do guaiacol em gemas e na produtividade de macieiras. A pesquisa foi conduzida na Universidade Estadual do Centro-Oeste (Unicentro), em Guarapuava, PR, em plantas em formacao e inicio de producao (safras 2013/2014 e 2014/2015, respectivamente), com as cultivares de macieira Gala Real II e Fuji Suprema. Os tratamentos constaram da aplicacao de oleo mineral e misturas deste com oleo vegetal emulsionavel, oleos vegetais de soja e de girassol e cianamida hidrogenada. As avaliacoes consistiram na verificacao da brotacao e atividade enzimatica das gemas, do desenvolvimento vegetativo, da fenologia da floracao e das caracteristicas produtivas. Em macieiras cv. Fuji Suprema, a mistura de oleo mineral 2% e oleo vegetal emulsionavel 4% apresenta potencial para inducao da brotacao, reducao do vigor das plantas, concentracao e antecipacao da florada e aumento do numero de frutos por planta e da produtividade. A mistura de oleo mineral e vegetal tem menor eficiencia para inducao da brotacao de macieiras cv. Gala Real II, quando comparada ao oleo mineral e cianamida hidrogenada. A aplicacao de oleo vegetal e mineral nao altera a atividade da enzima catalase e nenhum dos produtos testados altera a atividade da enzima peroxidase do guaiacol, 24 horas apos a aplicacao.

Extrato de Lentinula edodes no controle da antracnose do feijoeiro

Extract of Lentinula edodes in the control of anthracnosis in bean Anthracnose (Colletotrichum lindemuthianum) is one of the main diseases of bean, as it affects the quality and production of the bean. In the research we searched for substances with potential in the control of this disease, especially basidiomycetes. The aqueous extract of the mushroom Lentinula edodes was sprayed at concentrations of 0, 5, 10 and 20% on common bean plants, totaling three applications, and after 24 hours of the first spray C. lindemuthianum (105 conidia mL-1). With the beginning of the first symptoms the severity of the disease was evaluated weekly, totalizing four evaluations. With these results it was possible to calculate the Area Under the Disease Progress Curve (AUDPC). Peroxidase activity was evaluated 24 hours after application of the treatments and 24 hours after inoculation of the pathogen. It was verified that the aqueous extract of the mushroom was not efficient in the control of the anthracnose, in spite of allowing the increase of the peroxidase activity. New studies must be performed to confirm these results, to better elucidate the data, taking the experiment to field.

Influência de diferentes extratos aquosos de plantas medicinais no desenvolvimento de Colletotrichum gloeosporioides e de Fusarium moniliforme

The objective of this study was to evaluate the influence of aqueous extracts of the medicinal plants rosemary, garlic, clove, sage, lemongrass, oregano and black pepper in the in vitro development of Colletotrichum gloeosporioides and Fusarium moniliforme. The extracts were obtained by infusing 60 g of each medicinal plant in 200 mL of boiling water. Each aqueous extract was fractionated in the concentrations of 0, 5, 10 and 20% (w:v) and incorporated into the PDA (potato dextrose agar) culture medium before sterilization by autoclaving. Later, an 8 mm diameter disc of each pathogen mycelium was transferred to the center of the Petri dishes. After 24, 48 and 96 hours of incubation in a growth chamber at 22 ± 2 oC and a photoperiod of 12 hours, we evaluated the mycelial growth of F. moniliforme, and C. gloesporioides. In the last period of incubation, we quantified the production of conidia of each fungus. For the germination test, we added, into the wells of an ELISA test plates, a 40 µL aliquot of each extract at the concentrations of 0, 5, 10 and 20% and another aliquot of a suspension of conidia of each pathogen. After 24 hours at 22 ± 2 oC in the dark, the germination of the fungi was stopped with the addition of 20 µL of lactophenol. Then, we evaluated the germination of conidia. The experiments followed a completely randomized 7 x 4 factorial design (medicinal plants x concentrations) with four replications. For both pathogens, the aqueous extract of garlic and clove showed a greater or total inhibition of the mycelial growth, when compared to the other extracts. For the C. gloeosporioides, the clove extract showed a lower number of conidia at all concentrations tested, and the garlic extract at 20% showed not conidial germination. The garlic extract was efficient to reduce the conidial number and germination of F. moniliforme at 20%. Extracts of rosemary, clove, oregano and black pepper, in the highest concentrations, had positive effect in reducing the production of spores of the same fungus.