The fungal genus Curvularia is associated with a number of diseases in plants, commonly producing foliar spots in forage grasses. The objective of this study was to characterize the morphological and molecular diversity of the isolates of Curvularia sp. associated with Andropogon seeds, and to assess both their capacity to transmit disease and the pathogenicity of this fungus to crop. Ten isolates of Curvularia sp. were sourced from Andropogon seeds from agricultural producing regions in the Brazilian states Tocantins and Pará. Morphological characterization was achieved by observing fungus colonies and conidia and molecular characterization by DNA extraction and amplification with sequence-specific primers.
The aim of this study was to determine the most adequate stocking density for tambatinga during the initial grow-out phase in net pens
Weeds compete with agricultural crops for water, light, nutrients and space, besides having an extensive seed bank. However, another aspect to be considered relates to few studies pointing out weeds as hosts of phytopathogenic fungi. Many fungi, the main cause of diseases in plants, are known to use seeds as an efficient means of survival and dispersal. The objective of this work was to evaluate the health of weed seeds and the pathogenicity of fungi associated to plants of agricultural importance. The seeds were collected manually in Cerrado areas located in the municipality of Gurupi, Tocatins, Brazil. The blotter test method was used to evaluate seed health. The incidence of fungi was evaluated through an individual analysis of seeds using a stereoscopic and an optical microscope. The pathogenicity of fungi from weed seeds was evaluated by inoculation in plants of agronomic interest and, when pathogenic, we inoculated them in the host plant of the fungus. Weed seeds have been identified in fungi of the genus Alternaria, Aspergillus, Bipolaris, Cladosporium, Curvularia, Fusarium, Nigrospora, Papularia, Rhizopus and Pythium. The seeds of Acanthospermum australe, Bidens pilosa, Cenchrus echinatus, Digitaria horizontalis, Echinochloa crus-pavonis, Eleusine indica, Ipomoea sp., Pennisetum setosum, Sida rhombifolia, Spermacoce latifolia, Tridax procumbens and Vernonia polyanthes carry and disseminate fungi that, once inoculated, cause infection in plants of agricultural importance, such as Oryza sativa, Phaseolus vulgaris, Vigna unguiculata, Zea mays and Glycine max.
Brazil is the largest producer, consumer, and exporter of forage seeds in the world. However, the high incidence of pathogens threatens the seed production system, resulting in decreases in production and quality. Currently, the emphasis has been placed on the use of alternative products as a way of maintaining productivity and environmental sustainability. Thus, the objective of this study was to evaluate the mycoflora associated with the commercial seeds of Brachiaria brizantha and Panicum maximum treated with chemical and alternative fungicide. To test with chemical and alternative treatments, seeds were subjected to fluazinam + thiophanate-methyl, fludioxonil + metalaxyl-M, noni essential oil, rosemary pepper essential oil, sulfuric acid. There was also an untreated control. The most efficient products in the control of incident fungi were, in decreasing order, fluazinam + thiophanate-methyl, fludioxonil + metalaxyl-M, noni essential oil, rosemary pepper essential oil, and sulfuric acid. Fungicides mainly controlled the genera Alternaria, Aspergillus, Bipolaris, Chaetomium, Cladosporium, Colletotrichum, Curvularia, Fusarium, Penicillium, Phoma and Rhizopus. Essential oils showed positive effects in controlling Bipolaris, Curvularia, and Fusarium. Sulfuric acid reduced the incidence of Bipolaris, Colletotrichum, Curvularia, Fusarium, Phoma, and Rhizopus. Seed treatment is one of the promising strategies for obtaining seeds of a healthy quality. As a result, the fungicides and botanical components listed above were promising in reducing fungi associated with forage seeds and can be used for seed treatments and in the development of new products with a natural base through essential oils.
Em um campo de produção de sementes de soja, as características relacionadas a qualidade das sementes não são uniformes e apresentam variação dentro da área de produção. O objetivo deste trabalho foi identificar a distribuição espacial da produção, da qualidade e do potencial de armazenamento de sementes de soja obtidas em condições de várzea tropical, na região de Lagoa da Confusão (Tocantins, Brasil). Adotou-se uma amostragem sistemática e malha amostral regular com distância de 100x100 m entre cada ponto (um ponto por hectare). Na colheita, as plantas foram trilhadas com as sementes sendo limpas, pesadas, secas e armazenadas até o momento das análises fisiológicas e sanitárias, realizadas à 50, 100, 150 e 200 dias após o armazenamento (DAA). Foi determinada a umidade atual do solo no momento da colheita. Os resultados mostraram que: a produtividade das sementes apresentou variação de 13,03% (195-342 g.m-²); os testes de germinação e do envelhecimento acelerado apresentaram aumento da variação com o tempo de armazenamento, com maior variabilidade neste último (24% a 96%) a 200 DAA; as propriedades analisadas apresentaram forte grau de dependência espacial, sendo possível identificar regiões com maior e menor qualidade de sementes de soja relacionadas ao vigor e também uma maior variação e distinção na área de estudo de acordo com o período de análises pós-colheita.
As plantas apresentam mecanismos complexos de defesa estrutural e bioquímica que podem ser ativados antes ou após o ataque de microrganismos fitopatogênicos. Dentre esses mecanismos, estão as proteínas relacionadas à patogênese (PRP) e a resposta hipersensível através da produção de espécies reativas de oxigênio (ERO), as quais auxiliam na defesa contra os fitopatógenos e redução da toxicidade dos radicais livres. A ativação deste sistema pode ser por fatores bióticos ou abióticos que podem estimular a atividade bioquímica, denominadas substâncias elicitoras, como óleos essenciais e seus constituintes. Estudos na área são necessários para aprofundar conhecimento e atingir a viabilidade técnica e econômica de seu uso em benefício da agricultura sustentável. Objetivou-se avaliar a atividade enzimática de plantas de meloeiro submetidas à aplicação de óleo essencial de noni (OE) e ácido octanóico (AO). Foram testadas diferentes concentrações dos tratamentos e como testemunhas: fungicida Cerconil® (0,2%) e estimulante vegetal Yantra®. As enzimas com atividade avaliada foram superóxido dismutase (SOD), quitinase (QUIT), ascorbato peroxidase (APX) e catalase (CAT). O ácido octanóico (0,1%) e óleo essencial (0,5%) foram os maiores ativadores da SOD dentre os tratamentos testados. A APX teve sua produção aumentada pela aplicação de ácido octanóico à 0,1%. O OE foi o maior ativador da CAT na concentração de 2%. Confirmando a atividade dos metabólitos secundários de Morinda citrifolia como ativadores do sistema de defesa e provável ação imediata contra microrganismos. Considerando assim compostos potenciais para o desenvolvimento de um bioproduto como substituto de defensivos agrícolas. Palavras-chave: bioprodutos, compostos naturais, Cucumis melo L., espécies reativas de oxigênio, óleo essencial.
Tropical and subtropical fruit production plays an important role in the country’s economic scenario and has been affected by root-knot nematode. The jaboticaba tree is a plant widely cultivated in Brazil, and among the problems of the crop is the root-knot nematode of the genus Meloidogyne. This study aimed to evaluate the hostability of jaboticaba tree cv. ‘Sabará’, in different inoculum concentrations of Meloidogyne incognita and Meloidogyne javanica. The inoculum used in the experiment was obtained from the roots of tomato cv. ‘Santa Cruz’. Jaboticaba trees were subjected to inoculation with concentrations of 0, 2000, 4000, and 8000 eggs + juvenile plant-1, for both species of nematodes. The plants of jaboticaba cv. ‘Sabará’ showed resistance concerning the development of M. incognita and M. javanica root-knot nematode with Reproduction Factor (RF) <1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.