Lilian Maria Arruda Bacchi

Atividade antifúngica de extratos vegetais sobre o desenvolvimento de fitopatógenos

The formation of an ecological conscience and the search for the preservation of the environment have generated the need to test natural products, targeting an alternative control of plant pathogens. In this way aimed at evaluating the potential of ten aqueous extracts on the in vitro development of phytopathogenic fungi. Were conducted six experimental trials in a completely randomized design with 11 treatments and 10 replications for each assay. The treatments consisted of crude aqueous extracts of garlic, rue, cinnamon, clove, horsetail, eucalyptus, mint, jabuticaba, melon-of-sao-caetano and neem in the concentration of 20%, more the control treatment (only PDA). The trials were carried out with the fungus Aspergillus sp., Penicillium sp., Cercospora kikuchii, Colletotrichum sp., Fusarium solani and Phomopsis sp. The extracts were filtered in paper wathman no 1, put in the water bath at 65oC for 1 hour, incorporated in PDA medium and after poured into Petri dishes, transferred to mycelial discs of pathogens (0.3 cm of diameter). Was determined the mycelial growth of the colony, the percentage of inhibition and the rate of growth of fungi. It was observed that the PDA medium containing the extracts of clove, garlic and cinnamon showed most antifungal activity on the plant pathogens, when compared to other extracts used, highlighting for the extract of clove, which inhibited the development of all pathogens tested.

Influência de diferentes metodologias de esterilização sobre a atividade antifúngica de extratos aquosos de plantas medicinais

Three experiments were conducted in the Laboratory of Phytopathology of Federal University of Grande Dourados, Mato Grosso do Sul State, Brazil, to evaluate in vitro the antifungal activity of aqueous extracts of garlic, cinnamon and clove subjected to different processes of disinfection and/or sterilization against the development of Fusarium solani. The experimental design for each trial was completely randomized, with 5 treatments and 8 replicates. Aqueous extracts at a concentration of 20% were subjected to the methods of filtering (FI), water bath at 65oC (WB), autoclaving at 100oC (AT1), autoclaving at 120oC (AT2) and control treatment (PDA alone). Subsequently, the extracts were incorporated into PDA medium, added to Petri dishes, to where F. solani mycelium discs of 0.3cm diameter were transferred. Then, the plates were incubated at 25oC with 12-h photoperiod. The treatments were analyzed as to mycelial growth of the colony, percentage of inhibition and growth rate of F. solani. Increased fungal growth was observed for the control treatment, demonstrating the antifungal potential of the extracts. The sterilization method influenced the efficiency of garlic and cinnamon extracts. For garlic, FI led to the best results, whereas for cinnamon extract there were no differences among the methodologies FI, WB and AT1. The different methods used did not interfere with the efficiency of the aqueous extract of clove.

Germinação carpogênica de Sclerotinia sclerotiorum sob diferentes resíduos e extratos de plantas cultivadas

The effects of crop residues and their extracts on Sclerotinia sclerotiorum are not well documented. Three experiments were conducted with crop residues and their ethanol and partition extracts. Oat, vetch, bean, pearl millet, corn and wheat were assessed under controlled conditions. Sclerotia covered with oat, vetch, bean and pearl millet residues did not germinate carpogenically. Ethanol extracts of oat and vetch residues were efficient in inhibiting carpogenic germination whereas pearl millet and wheat did not differ from control. All partitioned ethanol extracts inhibited germination. Crop residues negatively affected the number of apothecia per sclerotium.

Relação de massa e localização do escleródio no solo com germinação carpogênica de Sclerotinia sclerotiorum

Sclerotia of Sclerotinia sclerotiorum allow the fungus to conserve its pathogenic power for several years on the soil; however, there are incipient studies that relate the sclerotium mass and location on the soil to its pathogenicity. Thus, the aim of this study was to assess if the sclerotium mass and location on the soil can interfere in the carpogenic germination of S. sclerotiorum. Sclerotia were weighed and classified into six classes, (C1) sclerotia with mass inferior to 0.01 g, (C2) 0.01<0.02 g, (C3) 0.02<0.03 g, (C4) 0.03<0.04 g, (C5) 0.04<0.05 g, and (C6) 0.05<0.06 g. Then, they were stored in gerbox containing soil moistened up to 100% saturation and were allocated to the soil surface and buried to a 3-cm depth. Gerboxes were incubated in a BOD chamber, temperature of 20oC and 12 h photoperiod. The percentage of carpogenic germination was higher for sclerotia that were placed on the soil surface in all analyzed classes. Carpogenic germination tended to increase with the increase in the sclerotium mass; for the sclerotia placed on the soil surface, germination was 37.5, 62.5, 75, 87.5, 100 and 100%, while for buried sclerotia, it was 0, 37.5, 37.5, 62.5, 62.5 and 62.5% in C1, C2, C3, C4, C5 and C6, respectively. At the end of evaluations, buried sclerotia had fewer stipites and apothecia. On the soil surface, C4, C5 and C6 sclerotia originated more stipites and apothecia, while for buried sclerotia only C5 and C6 provided larger number of stipites and apothecia per sclerotium.

Avaliação da atividade fungicida de extratos e óleos essenciais sobre ferrugem asiática da soja

Os extratos e oleos essenciais extraidos de plantas tem grande potencial no controle de fitopatogenos, por sua acao fungitoxica direta, inibindo o crescimento micelial e a germinacao de esporos, e pela capacidade de induzir o acumulo de fitoalexinas nas plantas. Objetivou-se com esse trabalho avaliar o efeito de diferentes extratos metanolicos e oleos essenciais sobre a ferrugem asiatica da soja (Phakopsora pachyrhizi). O experimento foi realizado em casa-de-vegetacao e sala de incubacao. Utilizou-se o delineamento inteiramente casualizado com sete tratamentos e dez repeticoes. A cultivar de soja utilizada foi a BRS 245RR; os tratamentos constaram de oleos essenciais e extratos metanolicos dos generos Schinus terebinthifolius (aroeira-pimenteira), e Trichilia silvatica (quebra-machado, catigua-vermelho), surfactante Tween 80 a 1% (v/v) e a testemunha agua. As plantas foram pulverizadas com os respectivos tratamentos e inoculadas artificialmente com o fungo cerca de 24 horas depois. As caracteristicas analisadas foram: numero de foliolos/parcela; indice de clorofila; altura de plantas; intensidade da ferrugem asiatica da soja; numero de foliolos com ferrugem; numero de foliolos com aspecto queimado. As plantas pulverizadas com extrato de Schinus a 5% (m/v) e oleo de Schinus a 1% (v/v) mostraram maior intensidade da doenca, comparadas as pulverizadas com agua. Estes dois tratamentos e o oleo de Trichilia a 1% provocaram uma maior incidencia de foliolos queimados, indicando fitotoxicidade a cultura.

Associação de adjuvantes à picoxistrobina + ciproconazol no controle da ferrugem asiática da soja

ABSTRACT Atualmente, o Brasil e o segundo maior produtor de soja do mundo.Na safra 2011/2012, o Brasil produziu 75 milhoes de toneladas em 25milhoes de hectares com uma produtividade de 3.100 kg ha -1 .Aproximadamente, 10 milhoes de toneladas foram produzidas noestado de Mato Grosso do Sul (5).Entre os principais fatores que limitam a obtencao de altosrendimentos em soja estao as doencas. Os danos anuais na producaodevido as doencas sao estimados em cerca de 15% a 20%, entretanto, RESUMO Palavras-chave adicionais: Glycine max , Phakopsora pachyrhizi , surfactantes O principal problema fitossanitario da soja no Brasil e a ferrugemasiatica. O uso de fungicidas e uma medida eficiente no controle dadoenca. Substâncias adicionadas a calda, como os adjuvantes podeminfluenciar a eficacia do fungicida. Testou-se nas safras 2008/09 e2009/10 o efeito de seis adjuvantes (Assist  , Aureo , Break Thru , Joint  , Natur´l Oil e Silwet  ) adicionados a picoxistrobina +ciproconazol, alem da testemunha (sem fungicida) e da testemunhapadrao (Nimbus

Atividade de óleos e extratos vegetais sobre germinação carpogênica e crescimento micelial de Sclerotinia sclerotiorum

Te efect of methanolic extracts of Annona cacans, A. coriacea, A. crassiflora, A. dioica, A. sylvatica, Geophila repens, Guettarda viburnoides, Palicourea crocea, Schinus terebinthifolius e Trichilia silvatica, and A. cacans hexane, ethyl etila, aqueous and chloroform fractions and the essential oil of S. terebinthifolius on mycelial growth and carpogenic germination of Sclerotinia sclerotiorum was evaluated. Te concentrations are 1,000 ppm for the extracts and 100 ppm for the fractions. To evaluate the germination, carpogenic, extracts and fractions were incorporated in agar-water that was poured into gerboxes where 20 sclerotia were distributed. To evaluate the mycelial growth, essential oil of S. terebinthifolius in concentrations of 0, 100 and 1,000 ppm was incorporated into the PDA and then poured into Petri dishes, to where pathogen mycelial discs were transferred. Extracts of G. repens, P. crocea and S. terebinthifolius and fractions ethyl acetate and chloroform of Annona cacans reduced the carpogenic germination of sclerotia of S. sclerotiorum and the extract of A. cacans reduced the number of apothecia formed. Mycelial growth showed 10% inhibition at the highest concentration of essential oil of S. terebinthifolius.

Soybean production and carpogenic germination of Sclerotinia sclerotiorum under different cover crops

O trabalho teve por objetivo avaliar a influencia de diferentes coberturas vegetais de solo sobre a germinacao carpogenica de Sclerotinia sclerotiorum e sobre o desenvolvimento e rendimento da cultura da soja. Os tratamentos constaram da palhada de braquiaria, canola, cartamo, crambe, girassol e nabo forrageiro, mais um controle sem cobertura. As culturas de cobertura foram semeadas em vasos contendo 4,4 dm³ de solo do tipo Latossolo Vermelho Distroferrico. Apos 45 dias o material vegetal foi cortado em pedacos de modo a padronizar a quantidade de palha para 2800 kg ha-1. Posteriormente, sementes de soja foram semeadas e sete dias apos a emergencia das plântulas foram alocados dois esclerodios de S. sclerotiorum por vaso. Em relacao a germinacao carpogenica, foi analisado o tempo para a germinacao dos esclerodios e formacao dos apotecios, numero de estipes e apotecios por esclerodio e a porcentagem de apotecios formados. Na cultura da soja foi determinada a altura de plantas no florescimento e na colheita, indice relativo de clorofila, massa seca da parte aerea e de raiz, numero de vagens por planta, numero de sementes por vagem, rendimento, numero de nodulos por planta e a massa seca de nodulos. Com excecao ao cartamo, constatou-se que o uso de cobertura vegetal do solo reduziu a formacao de estipes e apotecios de S. sclerotiorum . As coberturas com braquiaria, girassol e nabo forrageiro aumentaram em 16, 10 e 6 dias respectivamente o periodo para a formacao do apotecio, porem, somente braquiaria reduziu a porcentagem de apotecios formados. A cobertura do solo com palha de girassol prejudicou o desenvolvimento e o rendimento da cultura da soja.

Fungicide association in the control of anthracnose in the soybean in Mato Grosso do Sul

The soybean is a worldwide agricultural product, and therefore justifies investments in reducing those factors that are unfavourable to production, such as anthracnose caused by Colletotrichum truncatum. Three experiments were carried out with the aim of evaluating the control of anthracnose by fungicides, either singly or in combination, in soybean shoots sown on two dates in the 2011/12 season, under the conditions found at Dourados and Maracaju in the State of Mato Grosso do Sul. An experimental design of randomised blocks with five replications was used. The treatments were: control, carbendazim 250 g a.i. ha-1, pyraclostrobin 66.5 g a.i. ha-1 + epoxiconazole 25 g a.i. ha-1, picoxystrobin 60 g a.i. ha-1 + cyproconazole 24 g a.i. ha-1, carbendazim 250 g a.i. g-1 + pyraclostrobin 66.5g a.i. ha-1 + epoxiconazole 25 g a.i. ha-1 and carbendazim 250 g a.i. ha-1 + picoxystrobin 60 g a.i. ha-1 + cyproconazole 24 g a.i. ha-1. Two fungicide applications were performed, the first when the disease was detected at development stage R2, and the second 19 days later. The following were evaluated: incidence and average severity, defoliation, plant height, first pod height, number of pods, productivity and thousand grain weight. Seed pathology was carried out focusing on the incidence of C. truncatum. The use of carbendazim, singly or combined, controlled anthracnose in the shoots and seeds of the soybean. The application of fungicides resulted in reduced defoliation, a lower percentage of diseased petioles, a greater number of pods, greater plant height and gains in productivity. Carbendazim + cyproconazole + picoxystrobin occasionally displayed greater control than did single carbendazim.

Germinação de uredinosporos de Phakopsora pachyrhizi e Puccinia kuehnii sob diferentes adjuvantes

In Brazil Phakopsora pachyrhizi and Puccinia kuehnii are important pathogens of soybeans and sugar cane, respectively. In vitro experiments were carried out in order to evaluate P. pachyrhizi and P. kuehniiurediniospore germination under different adjuvants used in fungicide sprays to control rust diseases. Petri dishes (80 mm diameter) containing 10 mL of agar-water (1.7%) were used. In each plate 1 mL of a spore suspension with 5x105 urediniospores and 1 mL solution of adjuvants with twice the concentratation for field sprays was added. Assist(r), Veget Oil(r), Natur Oil(r), Break Thru(r)Aureo(r), Silwet(r) and Nimbus(r) were evaluated. There was a control check treatment with water. P. pachyrhiziurediniospore germination was negatively affected by all adjuvants after 2 hours of exposition. Urediniospores of the Asian soybean rust exposed to Assist(r), Break Thru(r), Aureo(r) and Nimbus(r) had lower germination rates. Germination of P. kuehnii urediniospores was lower in all adjuvant treatments after 4 hours of exposition. At 8 hours of Veget Oil(r) and Break Thru(r) exposure urediniospores of the orange rust pathogen had 96.6 and 94.8% reduction in germination compared to control check treatment.