Conservação pós-colheita de frutos de maracujá-amarelo por derivados de capim-limão (Cymbopogon citratus)Postharvest conservation of yellow passion fruit from lemon grass (Cymbopogon citratus) derivatives

O maracujá-amarelo (Passiflora edulis f. flavicarpa, Deg.) é uma das principais frutíferas cultivadas no Brasil. O manejo pós-colheita representa fator limitante para o maracujá-amarelo, pois ocorre aumento na suscetibilidade à doenças e à alterações físico-químicas no fruto. Objetivando aumentar a vida útil de frutos do maracujazeiro, foi avaliado o efeito de produtos alternativos derivados de capim-limão (Cymbopogon citratus) sobre as características físico-químicas de frutos do maracujazeiro em pós-colheita. Foram avaliados o óleo essencial (0,025, 0,05 e 0,1%), extrato aquoso (10%), hidrolato (5 e 10%) e citral (0,1%) em delineamento inteiramente casualizado com quatro repetições. Foram avaliados o índice de murchamento, rendimento de suco, redução de massa, diâmetros longitudinal e equatorial, coloração da casca, sólidos solúveis totais, açúcares redutores, açúcares não redutores, açúcares totais, pH, acidez total titulável, vitamina C e a relação sólidos solúveis totais e acidez total titulável. Os frutos de maracujá-amarelo foram tratados após a colheita e as avaliações foram realizadas durante 15 dias de armazenamento dos frutos sob condições de temperatura ambiente. Os derivados de C. citratus promoveram alterações nos atributos físico-químicos dos frutos de maracujá-amarelo. Melhores resultados foram obtidos com óleo essencial a 0,1% que promoveu maior rendimento de suco e menor perda de peso nos frutos tratados, representando alternativa na conservação pós-colheita. O produto citral 0,1% mostrou efeito fitotóxico, comprometendo os atributos físico-químicos relacionados à maturação e qualidade dos frutos.Abstract The yellow passion fruit (Passiflora edulis f. flavicarpa, Deg.) is one of the major fruit crops in Brazil. The post-harvest management is a limiting factor for the culture because there is an increase in susceptibility to diseases and physicochemical changes in the fruit. With the objective of increasing the shelf life of passion fruits, it was evaluated the effect of alternative products derived from lemon grass (Cymbopogon citratus) on the physicochemical characteristics of passion fruit in postharvest. It was evaluated the essential oil (0.025, 0.05 and 0.1%), aqueous extract (10%), hydrolate (5 and 10%) and citral (0.1%) in a completely randomized design with four replications. It was also evaluated the rate of wilting, the juiciness, mass reduction, longitudinal and equatorial diameters, peel color, soluble solids, reducing sugars, non-reducing sugars, total sugars, pH, titratable acidity, vitamin C and the relation between total soluble solids and titratable total acidity. The fruits of passion fruit were treated after harvest and assessments were performed during 15 days of storage of the fruits under ambient temperature conditions. The lemon Grass derivatives promoted changes in physicochemical attributes of the passion fruits. Best results were obtained with 0.1% essential oil that promoted higher juice yield and less weight loss in the treated fruits, representing alternative for the postharvest conservation of the fruits. The citral product showed phytotoxic effect, affecting the physical and chemical attributes related to maturation and fruit quality

CONTROLE DE DOENÇAS EM CULTIVO ORGÂNICO DE MORANGUEIRO COM PRODUTOS NATURAIS

O objetivo foi avaliar a eficiência do extrato de Rosmarinus officinalis e Ruta graveolens, da biomassa cítrica e do óleo de nim no controle de Colletotrichum sp. e Rhizopus sp. em morango. Para atividade antimicrobiana in vitro, os extratos (0,5%, 1%, 5% e 10%) e a biomassa cítrica e o nim (0,1%, 0,25%, 0,5% e 1%) foi avaliado crescimento micelial e esporulação. A campo, morangueiro dos cultivares Camarosa e Dover foram pulverizados nas mesmas concentrações utilizadas in vitro, tendo como testemunhas água e Super Magro (40 mL L-1 água) sendo avaliada incidência de podridões e produtividade. Biomassa cítrica, óleo de nim e os extratos apresentaram atividade antifúngica in vitro. As pulverizações reduziram a incidência de podridões e para produtividade, a arruda para o cv. Camarosa e a biomassa cítrica para o cv. Dover, apresentaram maior número de frutos planta-1, g planta-1 e ton ha-1. Verificou-se potencial no controle de doenças no morangueiro

Control of Alternaria solani and Xanthomonas vesicatoria in tomato by Pycnoporus sanguineus formulated extract

The continuous use of pesticides protecting plants from diseases can result in several damages due the environmental pollution and food residues. Thus, it is necessary the search for new plant diseases control technology. The objective of this study was to evaluate the in vitro antimicrobial activity against Alternaria solani and Xanthomonas vesicatoria and the control of early blight and bacterial spot on tomato plants, using stable formulation, as soluble powder, from Pycnoporus sanguineus. To determine the shelf life, the soluble powder was kept at 40 oC during 0, 60, 120 and 180 days and assayed with five concentrations (0, 50, 100, 150 and 200 mg L-1). When the shelf life and the best concentrations were defined, it was evaluated the time-interval of spraying of seven, 14 and 21 days. As control treatments were used the fungicides azoxystrobin (200 mg of active ingredient – a.i mL-1) to early blight and oxychloride (400 mg a.i. mL-1) to bacterial spot. There were no in vitro antifungal and antibacterial activities from extracts. The calculated concentration of P. sanguineus extract for the best control of diseases was 130 mg L-1, with 24 months of shelf live to soluble powder. In vivo, the P. sanguineus extract gave the same control of fungicides to early blight and bacterial spot, with values up to 79,31% of disease reduction, with spraying at seven days. These results show that the aqueous extract obtained from P. sanguineus soluble powder formulation, can protect tomato plants against early blight and bacterial spot, probably by resistance induction.  The continuous use of pesticides protecting plants against diseases can result in several damages due the environmental pollution and food residues. Thus, it is necessary the search for new plant diseases control technologies. The objective of this study was to evaluate the in vitro antimicrobial activity against Alternaria solani and Xanthomonas vesicatoria and the control of early blight and bacterial spot on tomato plants, using stable formulation, as soluble powder, from Pycnoporus sanguineus. To determine the shelf life, the soluble powder was kept at 40 ºC during 0, 60, 120 and 180 days and assayed with five concentrations (0, 50, 100, 150 and 200 mg L-1). When the shelf life and the best concentrations were defined, it was evaluated the time-interval of spraying of seven, 14 and 21 days. As control treatments were used the fungicides azoxystrobin (200 mg of active ingredient – a.i mL-1) to early blight and oxychloride (400 mg a.i. mL-1) to bacterial spot. There were no in vitro antifungal and antibacterial activities from extracts. The calculated concentration of P. sanguineus extract for the best control of diseases was 130 mg L-1, with 24 months of shelf live to soluble powder. In vivo, the P. sanguineus extract gave the same control of fungicides to early blight and bacterial spot, with values up to 79.31% of disease reduction, with spraying at seven days. These results show that the aqueous extract obtained from P. sanguineus soluble powder formulation, can protect tomato plants against early blight and bacterial spot, probably by resistance induction

EFEITO DE EXTRATOS DE SECREÇÕES GLANDULARES DE ANFÍBIOS NA FERRUGEM ASIÁTICA (Phakopsora pachyrhizi) E BIOMETRIA DE PLANTAS DE SOJA

The objective of this study was to analyze the effects of glandular secretion extracts from Rhaebo guttatus and Rhinella marina on TMG 132 RR soybean cultivar against the fungi Phakopsora pachyrhizi. Thirty days after seeding, a spontaneously arise of the disease was noticed and, two days after the arise of the first pustules, plants were treated with glandular secretion extracts at the concentrations 0,1; 0,2; 0,3; 0,4 e 0,5 mg mL-1, acibenzolar-S-methyl (500 L ha) and distilled water. None of the treatments resulted in statistical differences at the photosynthetic rates of the plants for chlorophyll a, chlorophyll b and total chlorophyll content. Glandular secretion extracts of R. guttatus and R. marina were not effective to reduce disease severity. There wasn’t statistical difference among treatments for defoliation percentage. For the biometrical evaluations, glandular secretion extracts of R. guttatus resulted in statistical difference only for the variable plant height but not for the remaining variables. Glandular secretion extracts of R. marina resulted in statistical difference only for number of root nodules but was not significant for the remaining variables.E Extratos de secreções de anfíbios da família Bufonidae têm sido estudados pelo potencial de controle direto de fitopatógenos, bem como na ativação de mecanismos de defesa contra doenças em plantas. Assim, este estudo analisa os efeitos de extratos de secreções glandulares de Rhaebo guttatus e Rhinela marina contra o fungo Phakopsora pachyrhizi e na biometria de plantas de soja da cultivar TMG 132 RR. Aos 30 dias após semeadura, notou-se o surgimento espontâneo da doença e, dois dias após o surgimento das primeiras pústulas, as plantas foram tratadas com extratos de secreções glandulares nas concentrações de 0,1; 0,2; 0,3; 0,4 e 0,5 mg mL-1, acibenzolar-S-metil (500 L ha) e água destilada. Com relação ao número total de trifólios, teores de clorofila a, b e total não houve diferença estatística entre os tratamentos. Nas avaliações biométricas, o extrato de secreção glandular de R. guttatus proporcionou diferença estatística apenas na variável altura de plantas. Quando as plantas foram tratadas com extrato de secreção glandular de R. marina, houve diferença estatística no número de nódulos, porém, sem diferença estatística para as demais variáveis analisadas. Conclui-se que extratos de secreções glandulares de R. guttatus e R. marina não controlam ferrugem asiática da soja; porém concentrações de 0,1mg mL-1, 0,2 mg mL-1 e 0,3 mg mL-1 de extrato de secreção glandular de R. guttatus promovem maior altura de plantas e extrato de secreção glandular de R. marina, nas concentrações de 0,1mg mL-1, 0,2 mg mL-1 e 0,4 mg mL-1, afeta negativamente o número de nódulos. Palavras-chave: altura de plantas; glândulas parotóides; Rhaebo guttatus; Rhinella marina; oleaginosa.   Effect of extracts from amphibian glandular secretions on asian rust (Phakopsora pachyrhizi) and biometry of soybean plants   ABSTRACT: Extracts from secretions of amphibians of the Bufonidae family were studied for their potential for direct control of phytopathogens, as well as for the activation of mechanism of defense against plant diseases. Thus, this study assessed the effects of glandular secretion extracts from Rhaebo guttatus and Rhinella marina against the fungi Phakopsora pachyrhizi and biometric responses on TMG 132 RR soybean cultivar. Thirty days after seeding, a spontaneously arise of the disease was noticed and, two days after the arise of the first pustules, plants were treated with glandular secretion extracts at the concentrations 0,1; 0,2; 0,3; 0,4 e 0,5 mg mL-1, acibenzolar-S-methyl (500 L ha) and distilled water. None of the treatments resulted in statistical differences at the photosynthetic rates of the plants for chlorophyll a, chlorophyll b and total chlorophyll content. For the biometrical evaluations, glandular secretion extracts of R. guttatus resulted in statistical difference only for the variable plant height variable. Glandular secretion extracts from R. marina resulted in statistical difference only for number of root nodules but was not significant for the remaining variables. The results showed that glandular secretion extracts from R. guttatus and R. marina does not control Asian soybean rust; however glandular secretion extracts from R. guttatus at the concentrations 0,1mg mL-1, 0,2 mg mL-1 e 0,3 mg mL-1 promotes greater plant height. The glandular secretion extracts from R. marina at the 0,1mg mL-1, 0,2 mg mL-1 e 0,4 mg mL-1 negatively affects the number of plant nodules. Keywords: height of plants; paratoid gland; Rhaebo guttatus; Rhinella marina; oleaginous

Atividade fungitóxica in vitro de extratos vegetais sobre o crescimento micelial de fungos fitopatogênicos

Medicinal plants have active compounds in their composition produced from secondary metabolism, which can have fungistatic and /or fungitoxic action on the development of phytopathogens. The objective of this work was to study the effect of aqueous extracts of Ocimum basilicum, Baccharis trimera and Cnicus benedictus on mycelial growth of plant pathogens. The experimental design had three medicinal plants, six concentrations of each aqueous extract (1%, 5%, 10%, 15%, 20%, 25% and 50%), five fungus - Alternaria alternata, Colletotrichum graminicola, Phytophthora sp., Rhizoctonia solani and Sclerotinia rolfsii, and four repetitions for each treatment. The variables analyzed were: inhibition of mycelial growth, mycelial growth and area under the curve of mycelial growth. The aqueous extracts in different concentrations showed significant interactions with the analyzed variables, demonstrating that they have potential to control these pathogens.Plantas medicinais apresentam em sua composição princípios ativos derivados do metabolismo secundário que apresentam ação fungistática e/ou fúngitóxica no desenvolvimento de fungos fitopatogênicos. Este trabalho teve como objetivo estudar extratos aquosos das plantas medicinais Ocimum basilicum, Baccharis trimera e Cnicus benedictus no crescimento in vitro de fitopatógenos. O delineamento experimental inteiramente casualizado contou com três espécies medicinais, seis concentrações de cada extrato aquoso (1%, 5%, 10%, 15%, 20%, 25% e 50%), cinco fitopatógenos - Alternaria alternata, Colletotrichum graminicola, Phytophthora sp., Rhizoctonia solani e Sclerotinia rolfsii, cada um com quatro repetições. As variáveis analisadas foram inibição do crescimento micelial (ICM), crescimento micelial final (CMF) e área abaixo da curva do crescimento micelial (AACCM). Os extratos aquosos em diferentes concentrações apresentaram interações significativas para as variáveis analisadas, demonstrando potencial na inibição do crescimento destes fitopatógenos

Controle de doenças foliares do milho com fosfito de potássio

Esse estudo teve como objetivo avaliar a eficiência da aplicação de fosfito de potássio (PHOS UP PK 28-26®) em diferentes doses e estádios de crescimento da planta para o controle dePhaeosphaeria maydis, Cercospora zeae-maydis e Exserohilum turcicum na cultura do milho 2a safra, bem como a produtividade dos híbridos. Dois experimentos distintos com fosfito, testemunha sem aplicação e fungicida epoxiconazole + piraclostrobina (Ópera®), foram conduzidos nas safras agrícolas, 2008/2009 e 2010, no mesmo local. O delineamento experimental foi em blocos completos, com tratamentos ao acaso e quatro repetições. Foram avaliadas a severidade das doenças com escala diagramática e a produtividade. Foram observados diferentes comportamentos de acordo com a cultivar e as safras avaliadas, no entanto, o fosfito diminuiu a severidade das doenças foliares de milho. O tratamento 2,0 L ha-¹ nos estágios V6 e V10 apresentou controle intermediário entre o fungicida e a testemunha sem aplicação, reduzindo a severidade das doenças avaliadas. Os tratamentos com fungicida promoveram incremento de produtividade

Utilização de compostos bioativos de plantas medicinais na pós-colheita de tomate

Various methods are been used to control post-harvest diseases of tomato fruits. With the increasing restrictions on the use of fungicides, due the food safety and environmental impacts, the use of alternative methods and biological control of postharvest diseases have been stimulated. The aim of this work was to investigate the effect of alternative products in post-harvest treatment of tomato “Delta” and “Debora” produced under two cropping systems: intermediate (IS) and conventional system (CS). The components evaluated were the reduction of fresh mass, pH, soluble solids (SS), titratable acidity (TA) and the pathogens incidence after being treated by immersion with acibenzolar-S-methyl (ASM), Azadirachta indica crude extract, citric biomass extract and fumigation with essential oils (EO) of Syzygium aromaticum and Citrus aurantium ssp. bergamia. The products did not affect the parameters analyzed in the fruits from the CS, regardless of cultivar. In the fruits produced in IS was observed influence of the treatments. For weight reduction, were observed the lowest values in fruits of “Debora” treated with EO and ASM. Were observed also, the highest values of SS and TA in fruits “Debora” treated with S. aromaticum EO and ASM. The fruits “Delta” had the highest pH when treated with S. aromaticum EO.Vários métodos são usados para controle de doenças em pós-colheita de frutos de tomate. Com a crescente restrição ao uso de fungicidas, por questões de segurança alimentar e impacto ambiental, tem-se estimulado o uso de métodos alternativos para controle de doenças pós-colheita. O objetivo deste trabalho foi verificar o efeito de produtos alternativos na conservação e no controle de doenças pós-colheita de tomate cv. Delta e Débora, obtidos de sistemas de cultivo convencional (SC) e em transição ao orgânico (SO). Os frutos foram tratados por imersão (1 min) com acibenzolar-S-metil (ASM), extrato bruto de Azadirachta indica e extrato de biomassa cítrica, e por fumigação com os óleos essenciais (OE) de Syzygium aromaticum e de Citrus aurantium ssp. bergamia. Após 14 dias de armazenamento em temperatura ambiente avaliou-se a perda de massa, pH, sólidos solúveis (SS), a acidez total titulável (ATT) e a incidência de patógenos. Os resultados mostraram que os tratamentos não influenciaram nos parâmetros analisados nos frutos oriundos do SC, para ambas as cultivares. Para os frutos produzidos no SO, observou-se menor perda de massa e maiores valores de SS e ATT para a cv Débora, tratados com os OEs e ASM. Os frutos da cv Delta, apresentaram os maiores valores de pH quando tratados com OE de S. aromaticum. Nenhum dos tratamentos reduziu a incidência de doenças pós-colheita

Common bean seed germination and seedling emergence under inoculation with biostimulators

Biostimulating microorganisms have protector effect against pathogenic agents, affect the stand formation, promote plant growth, and increase yield of agricultural crops. Thus, the objective of this work was to evaluate the seed germination and seedling emergence of different common bean cultivars as a function of treatments with Bacillus subtilis BV02 and Trichoderma asperellum BV10. Germination tests in paper rolls and sand were conducted in a completely randomized design, with a 2×4 factorial arrangement consisted of two cultivars, namely Campos Gerais (CG) and Estilo (ES), and four microorganism treatments, namely B. subtilis BV02 (BS), T. asperellum BV10 (TA), B. subtilis BV02 + T. asperellum BV10 (BS+TA), and Control. The variables analyzed were: germination speed index (GSI), emergence speed index (ESI), germination percentage, emergence percentage, root length, seedling height, and root and shoot fresh and dry weights. The CG cultivar had higher GSI, ESI, root length, seedling height, shoot fresh weight, root fresh weight, and shoot dry weight than the ES cultivar in the paper roll and sand tests. The common bean seed inoculation with BS+TA increased seedling height, shoot fresh weight, shoot dry weight, and root length in the ES cultivar. The CG cultivar had higher GSI, ESI, root length, root fresh weight, and root and shoot dry weights than the ES cultivar. The treatment of seeds with BS+TA is recommended to improve the performance of common bean seedlings of the ES cultivar

Utilização de compostos bioativos de plantas medicinais na pós-colheita de tomate

Various methods are been used to control post-harvest diseases of tomato fruits. With the increasing restrictions on the use of fungicides, due the food safety and environmental impacts, the use of alternative methods and biological control of postharvest diseases have been stimulated. The aim of this work was to investigate the effect of alternative products in post-harvest treatment of tomato “Delta” and “Debora” produced under two cropping systems: intermediate (IS) and conventional system (CS). The components evaluated were the reduction of fresh mass, pH, soluble solids (SS), titratable acidity (TA) and the pathogens incidence after being treated by immersion with acibenzolar-S-methyl (ASM), Azadirachta indica crude extract, citric biomass extract and fumigation with essential oils (EO) of Syzygium aromaticum and Citrus aurantium ssp. bergamia. The products did not affect the parameters analyzed in the fruits from the CS, regardless of cultivar. In the fruits produced in IS was observed influence of the treatments. For weight reduction, were observed the lowest values in fruits of “Debora” treated with EO and ASM. Were observed also, the highest values of SS and TA in fruits “Debora” treated with S. aromaticum EO and ASM. The fruits “Delta” had the highest pH when treated with S. aromaticum EO.Vários métodos são usados para controle de doenças em pós-colheita de frutos de tomate. Com a crescente restrição ao uso de fungicidas, por questões de segurança alimentar e impacto ambiental, tem-se estimulado o uso de métodos alternativos para controle de doenças pós-colheita. O objetivo deste trabalho foi verificar o efeito de produtos alternativos na conservação e no controle de doenças pós-colheita de tomate cv. Delta e Débora, obtidos de sistemas de cultivo convencional (SC) e em transição ao orgânico (SO). Os frutos foram tratados por imersão (1 min) com acibenzolar-S-metil (ASM), extrato bruto de Azadirachta indica e extrato de biomassa cítrica, e por fumigação com os óleos essenciais (OE) de Syzygium aromaticum e de Citrus aurantium ssp. bergamia. Após 14 dias de armazenamento em temperatura ambiente avaliou-se a perda de massa, pH, sólidos solúveis (SS), a acidez total titulável (ATT) e a incidência de patógenos. Os resultados mostraram que os tratamentos não influenciaram nos parâmetros analisados nos frutos oriundos do SC, para ambas as cultivares. Para os frutos produzidos no SO, observou-se menor perda de massa e maiores valores de SS e ATT para a cv Débora, tratados com os OEs e ASM. Os frutos da cv Delta, apresentaram os maiores valores de pH quando tratados com OE de S. aromaticum. Nenhum dos tratamentos reduziu a incidência de doenças pós-colheita