This study aimed to assess the ability of silicon (Si) to potentiate defense enzyme activities in rice leaf sheaths and thus reduce sheath blight, caused by Rhizoctonia solani, development. Rice plants of BR-Irga 409 and Labelle cultivars were grown in a hydroponic solution containing 0 (-Si) or 2 mM (+Si) Si and inoculated with R. solani. Silicon concentration in the leaf sheaths was significantly higher in the +Si plants than the -Si plants by 727% for BR-Irga 409 and 714% for Labelle. The area under relative lesion expansion progress curve was significantly lower for +Si plants than -Si plants, by 34.2% for BR-Irga 409 and 30.59% for Labelle. Increases in the activities of phenylalanine ammonia-lyases, peroxidases, polyphenoloxidases and chitinases in the leaf sheaths of plants supplied with Si, especially of those from BR-Irga 409, led to reduced progress of sheath blight lesions.

Soil fumigation with the synthetic essential oil of mustard (93% allyl isothiocyanate) (EOM) was evaluated as a substitute of bio-fumigation with cruciferous plant species, using Sclerotium rolfsii and Sclerotinia sclerotiorum as test pathogens, together with its non-target effect on the general population of soil microorganisms. The mortality of the sclerotia of both fungi was dependent upon the concentration of EOM and the exposure period. Exposure to the EOM vapors delayed in vitro germination of the sclerotia.Total germination of the control sclerotia of S. rolfsii, after 120 h incubation, was 94%, of which 88% germinated within 48 h. In contrast, to the total germination of 77% or 47%, less than 3% germinated in 48 h when exposed for 4 or 7 days to 50 µl EOM/L. Exposure to 100 µl/l for 4 or 7 days resulted in the mortality of 50 and 100% sclerotia, respectively. The tendency for delayed germination and mortality was similar for the sclerotia of S. sclerotiorum. No viable sclerotia of either fungus were detected to the depth of 10 cm in the air dried, moist or wet soil fumigated for 7 days with the EOM at the rate of 150 µl/L. In the field plots, no viable sclerotia of S. rolfsii were detected after 7-day exposure to the EOM applied to the upper soil layer at the rate of 9, 12, or 18 ml/m² and covered with a plastic sheet, while 73, 50 and 15%, respectively, were recovered from uncovered plots. In field plots, the fluorescein diacetate hydrolysis decreased by EOM treatment. However, the colony forming units of actinomycetes and bacteria increased, but those of fungi decreased significantly. Soil fumigation with EOM can be used with several advantages, as a substitute of bio-fumigation with cruciferous plant species.

A ferrugem, causada por Hemileia vastatrix, é a principal doença e a que mais reduz a produção do cafeeiro no Brasil. Novos métodos de controle que podem reduzir a intensidade da ferrugem e serem integrados com a resistência genética e o controle químico precisam ser investigados para aperfeiçoamento do seu manejo. Considerando que várias espécies de plantas supridas com silício (Si) apresentam aumento da resistência a diversos patógenos, este estudo examinou o possível efeito do Si em aumentar a concentração de ácido clorogênico (AC) em folhas de cafeeiro e, consequentemente, o nível de resistência à ferrugem. Plantas de cafeeiro (cv. "Catuaí Vermelho IAC 44") crescidas por 35 dias em solução nutritiva contendo 0 (-Si) e 2 mM Si (+Si) foram inoculadas com H. vastatrix. A concentração foliar de Si foi de 0,36 e 0,42 dag/kg e a área abaixo da curva do progresso da ferrugem foi de 154,5 e 119,4, respectivamente, para os tratamentos -Si e +Si, mas não houve diferença significativa entre os dois tratamentos. Para plantas não inoculadas com H. vastatrix, a concentração foliar de AC total e ácido quínico-cafeoil (AQC) foi similar entre os tratamentos -Si e +Si. Embora tenha ocorrido aumento de 236,4 e 257,1%, respectivamente, para AC total e AQC para o tratamento +Si quando comparado ao tratamento -Si aos 30 dias após inoculação com H. vastatrix, a severidade da ferrugem não decresceu, pois o fungo já havia colonizado os tecidos foliares. Assim, independente do aumento na concentração foliar de AC, a resistência do cafeeiro à infecção por H. vastatrix não foi potencializada pelo Si.

Rust, caused by Hemileia vastatrix, is the main disease that decreases coffee production in Brazil. New and enhanced methods to reduce rust intensity that can be integrated with modern genetic and chemical approaches need to be investigated. Considering that many plant species supplied with silicon (Si) show increased resistance to several pathogens, this study examined the possible effect of this element in increasing chlorogenic acid (CA) concentrations in coffee leaves and, consequently, increasing the level of resistance to rust. Plants (cv. "Catuaí Vermelho IAC 44") were inoculated with H. vastatrix after growing for 35 days in a hydroponic culture amended with 0 (-Si) or 2 (+Si) mM Si. Concentration of Si in leaf tissues was of 0.36 and 0.42 dag/kg for -Si and +Si treatments, respectively, but without a statistically significant difference. The area under rust progress curve was 154.5 and 119.4 for -Si and +Si treatments, respectively, but without significant statistical difference. For non-inoculated plants, the concentrations of total CA and caffeoyl-quinic acid (CQA)compounds (diCQA) were similar between -Si and +Si treatments. Even though there was an increase of 236.4 and 257.1%, respectively, for total CA and diCQA for +Si when compared to -Si treatment at 30 days after inoculation with H. vastatrix, reduction on rust severity was not obtained once the fungus had already colonized the leaf tissues. Therefore, regardless of the increase in the concentrations of chlorogenic acid on leaves, coffee resistance to H. vastatrix infection was not potentialized by Si.

A ferrugem, causada por Hemileia vastatrix, é a principal doença do cafeeiro. Este trabalho avaliou o efeito do silício (Si) em alguns componentes de resistência do cafeeiro à ferrugem e o possível aumento na atividade de quitinases (QUI), β-1,3-glucanases (GLU) e peroxidases (POX). Mudas de cafeeiro (cv. Catuaí vermelho 44) foram crescidas em solução nutritiva de Clarck modificada, aerada, contendo 0 (-Si) ou 2 mmol L-1 Si (+Si) por 45 dias e inoculadas com H. vastatrix.Não houve diferença significativa entre os tratamentos -Si e +Si para o teor foliar de Si, mas o teor desse elemento nas raízes foi significativamente maior para o tratamento +Si. Os tratamentos -Si e +Si não foram estatisticamente diferentes para o período de incubação, período latente, número de pústulas por folha, área pustular, expansão de pústulas e área abaixo da curva do progresso da ferrugem. A atividade de QUI, GLU e POX aumentou após a inoculação com H. vastatrix, embora com aumentos e decréscimos durante as épocas de coletas. O Si não teve efeito pronunciado em maximizar a atividade dessas enzimas, salvo incrementos em épocas de coletas específicas. Os resultados deste estudo indicaram que o cafeeiro foi ineficiente em translocar o Si das raízes para a parte aérea, restringindo-o exclusivamente ao sistema radicular o que não garantiu o aumento da resistência do cafeeiro à ferrugem.

Coffee leaf rust, caused by Hemileia vastatrix, is the most important disease on coffee. This study aimed to evaluate the effect of silicon (Si) on some components of coffee resistance to rust and to determine if it could increase the activity of chitinases (CHI), β-1,3-glucanases (GLU), and peroxidases (POX). Coffee plants (cultivar "Catuaí vermelho 44") were grown on aerated Clarck’s nutrient solution containing 0 (-Si) or 2 mmol L-1 Si (+Si) for 45 days and inoculated with H. vastatrix. There was no significant difference between the -Si and +Si treatments for Si content in leaf tissue, but Si content in root tissue was significantly higher for the +Si treatment. The -Si and +Si treatments were not significantly different for incubation period, latent period, number of pustules per leaf, pustule size, pustule expansion, and area under rust progress curve. The activity of CHI, GLU, and POX increased after inoculation with H. vastatrix, even with increase or decrease in activities during the sampling times. There was not a pronounced effect of Si in increasing the activity of these enzymes, except for rare increases in specific sampling times. Results from this study indicated that coffee plants were inefficient in uptaking Si from the nutrient solution and translocating it to the shoot. Silicon was exclusively restricted to the root system, which did not guarantee an increase in coffee resistance to rust.

Diagnosticou-se o perfil dos consumidores de supermercados em Pato Branco (PR), com relação às suas preferências pelas plantas medicinais e condimentares, como subsídio à produção por pequenos produtores rurais. Os consumidores preferem produtos orgânicos, observam a aparência e o preço do produto, e vão ao mercado uma vez por semana, preferencialmente aos sábados. As dez plantas medicinais preferidas, em ordem decrescente, são camomila, anis, boldo, carqueja, guaco, malva, poejo, espinheira-santa, menta e sálvia. As dez plantas condimentares preferidas, em ordem decrescente, são cebola, cravo, canela, orégano, alho, nóz-moscada, pimentão, cebolinha, endro e salsinha.

The profile of supermarket users in Pato Branco city, Paraná State, Brazil, was obtained, related to their preference for medicinal and spice plants, as a subsidy to production by small farmers. The consumers prefer organic products observing the appearance and price of the product, and they go once a week to the market, preferably on Saturdays. The ten favorite medicinal plants are Chamomilla recutita, Pimpinella anisum, Vernonia condensata, Baccharis sp., Mikania sp., Malva sp., Cunilla sp., Maytenus sp., Mentha sp. and Salvia officinalis. The ten favorite spices are: Allium cepa, Eugenia caryophyllata, Cinnamomum zeylanicum, Origanum vulgaris, Allium sativum, Myristicia fragans, Capsicum annuum, Allium schoenoprasum, Anethum graveolens and Petroselinum crispum.