scholarly journals Alternativas de control en la pudrición radical de cebolla para el Valle de la Trinidad, Baja California

2018 ◽  
Vol 3 (1) ◽  
pp. 97-112
Author(s):  
Armando Pulido-Herrera ◽  
Emma Zavaleta-Mejía ◽  
Lourdes Cervantes-Díaz ◽  
Onécimo Grimaldo-Juárez

La pudrición radical en cebolla es la enfermedad más importante en el Valle de la Trinidad, Baja California, México. Con el propósito de evaluar estrategias de control para la enfermedad se realizaron tres experimentos durante 2007, 2008 y 2009. En el experimento I (2007) los tratamientos fueron: 1) Tiofanato metílico; 2) Smicobac (Trichoderma + Bacillus sp. + Azospirillum sp. + Pseudomonas sp.); 3) estiércol de bovino (EB); 4) residuos de cebolla (RC); 5) solarización plástico transparente (SPT), 6) solarización plástico negro (SPN); 7) SPT + EB; 8) SPT + RC; 9) SPN + EB; 10) SPN + RC; 11) Trichodef (Trichoderma harzianum); y 12) testigo. En el experimento II (2008), los tratamientos fueron los mismos excepto el tratamiento 2, sustituido por protector (extractos vegetales); y en el experimento III (2009) los tratamientos fueron: 1) SPT + estiércol de ovino (EO); 2) SPN + EO; 3) SPT; 4) SPN; 5) control biológico (Trichoderma spp.); y 6) control químico (2- (tiocianometiltio) benzotiazol 30%. Los resultados indicaron que los tratamientos solarización plástico transparente con o sin enmiendas orgánicas, presentaron incrementos significativos (p< 0.05) de 22 a 34% en el rendimiento y diámetro del bulbo con respecto al control biológico y químico; sin embargo, en estos dos últimos tratamientos la incidencia y severidad se redujo significativamente (p< 0.05), por lo que la solarización con plástico transparente y el control biológico, son alternativas viables para el control de la pudrición radical en cultivos de cebolla en Baja California, México.

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 347
Author(s):  
Elżbieta Patkowska

The principles of good agricultural and horticultural practice, considering both environmental protection and high yielding of plants, require modern cultivation methods. In modern agriculture, it is possible to use biostimulants that protect the soil against degradation and plants against phytopathogens and stress. The purpose of 3-year field and laboratory studies was to determine the effect of Trichoderma harzianum T-22 and other biostimulants on the health status of scorzonera (Scorzonera hispanica L.) plants and microorganism populations in the rhizosphere of this plant. For this purpose, Biosept Active (a.s.—grapefruit extract), Timorex Gold 24 EC (based on tea tree oil), Trianum P (spores of Trichoderma harzianum Rifai T-22) and Zaprawa Nasienna T 75 DS/WS fungicide (a.s.—tiuram) were applied for the pre-sowing seed dressing of scorzonera cv. “Duplex”. The number of seedlings and the health status of scorzonera plants were determined during three growing seasons. In each year of the study, mycological analysis of seedling roots and roots after scorzonera harvest was conducted to establish the quantitative and qualitative composition of fungi colonizing these parts. Moreover, microbiological analyses of scorzonera rhzisphere soil were conducted and served as the basis to determine the total population of fungi and bacteria (including Pseudomonas sp. and Bacillus sp.). Antagonistic activity of rhizosphere bacteria Pseudomonas sp., Bacillus sp. and fungi was determined based on laboratory tests on selected scorzonera soil-borne fungal pathogens (Alternaria scorzonerae, Fusarium culmorum, Fusarium oxysporum, and Rhizoctonia solani). The experiments showed that Trianum P most effectively protected the roots of scorzonera against infection by Alternaria alternata, A. scorzonerae, Neocosmospora solani, Fusarium spp., Sclerotinia sclerotiorum, Rhizoctonia solani, and Botrytis cinerea. The rhizosphere population of Bacillus sp. and Pseudomonas sp. in the treatments with Trianum P or Zaprawa Nasienna T 75 DS/WS was larger than in the other experimental treatments. A reverse relationship was observed in the population of rhizosphere fungi. The application of grapefruit extract, tea tree oil and Trichoderma harzianum T-22 increased antagonistic activity of Pseudomonas sp., Bacillus sp. and selected saprotrophic fungi against soil-borne fungal pathogens, especially Alternaria sp., Rhizoctonia sp., and Fusarium sp. In summary, Biosept Active, Timorex Gold 24 EC and Trianum P can be recommended as plant biostimulants in Scorzonera hispanica cultivation.


Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1637
Author(s):  
Elżbieta Patkowska ◽  
Elżbieta Mielniczuk ◽  
Agnieszka Jamiołkowska ◽  
Barbara Skwaryło-Bednarz ◽  
Marzena Błażewicz-Woźniak

The principles of good agricultural and horticultural practice, which consider both giving environmental protection and high yielding of plants, require modern cultivation methods. Modern cultivation of horticultural plants uses, for example, cover crops, living mulches, plant growth-promoting microorganisms (PGPMs), plant growth regulators (PGRs) and other biostimulants protecting the soil against degradation and plants against phytopathogens and stress. The purpose of field and laboratory studies was to determine the effect of Trianum P (containing Trichoderma harzianum Rifai T-22 spores), Beta-Chikol (a.s.—chitosan), Timorex Gold 24 EC (based on tea tree oil) and fungicide Zaprawa Nasienna T 75 DS/WS (a.s.—tiuram 75%) on the health of carrot (Daucus carota L.) plants and the microorganism population in the rhizosphere of this plant. Moreover, the antagonistic effect of rhizosphere fungi on selected carrot fungal pathogens was determined. Laboratory mycological analysis allowed one to determine the qualitative and quantitative composition of fungi colonizing the underground parts of carrot plants. In addition, the total population of fungi and bacteria was determined (including Bacillus sp. and Pseudomonas sp.) based on the microbiological analysis of the rhizosphere soil. The application of the plant growth-promoting fungus (Trichoderma harzianum T-22), chitosan and tea tree oil positively influenced the growth, development and health status of carrot plants. T. harzianum T-22, chitosan and fungicide most effectively protected carrots against infection by soil-borne fungi from the genus Alternaria, Fusarium, Haematonectria, Sclerotinia and Rhizoctonia. The rhizosphere population of Bacillus sp. and Pseudomonas sp. in the treatments with Trianum P or Zaprawa Nasienna T 75 DS/WS was bigger than in the other experimental treatments. A reverse relationship was observed in the population of rhizosphere fungi. T. harzianum T-22, chitosan and tea tree oil promoted the growth of antagonistic fungi (Albifimbria sp., Clonostachys sp., Penicillium sp., Talaromyces sp. and Trichoderma sp.) in the carrot rhizosphere. Antagonistic activity of these fungi towards Alternaria dauci, Alternaria radicina, Sclerotiniasclerotiorum and Rhizoctonia solani was higher after the application of the preparations compared to control. Consequently, Trianum P, Beta-Chikol and Timorex Gold 24 EC can be recommended as plant biostimulants in ecological agricultural production, including Daucus carota cultivation.


2017 ◽  
Vol 11 (2) ◽  
pp. 378-386
Author(s):  
Paula Mesa ◽  
Celsa García ◽  
Alba Marina Cotes

Entre las principales problemáticas que se presentan en la producción de papa se encuentra Spongospora subterranea (Wallr.) Lagerheim f. sp. subterranea, agente causal de la sarna polvosa y camanduleo, enfermedades que afectan los tubérculos, las raíces, que no cuentan con prácticas de manejo efectivas. Con el fin de generar una alternativa de manejo se evaluó el efecto en la reducción del camanduleo de microorganismos potencialmente biocontroladores de los géneros Trichoderma spp., Pseudomonas sp., Bacillus sp. y Streptomyces spp. Así mismo, se evaluó el biocarbón, la quitina y el quitosán, aditivos orgánicos que han demostrado actividad de control en otros patosistemas. Inicialmente, se estableció un ensayo para obtener el desarrollo de agallas en dos ambientes diferentes (Mosquera y Subachoque, Cundinamarca) y dos concentraciones de inóculo del protozoo. La evaluación se realizó 8 semanas después de la siembra (SDS), midiendo la severidad expresada como número de agallas por planta. Dado el consistente desarrollo de la enfermedad, se decidió establecer los ensayos en el Municipio de Subachoque, usando suelo naturalmente infestado con 1×103 esporosoros/gde suelo. Al aplicar los biocontroladores, se observó disminución (P>0,05) en el desarrollo de agallas con la mayoría de los microorganismos, siendo Streptomyces misionensis Ac006 el que más redujo la enfermedad en un 51,41%. Por otra parte, entre los aditivos evaluados, fue el quitosán al 0,5% con el que se obtuvo una mayor reducción (P≤0,05) en el número de agallas 62,58%. Estos resultados permiten sugerir el uso de estos tratamientos para el manejo del camanduleo de la papa.


2011 ◽  
Vol 104 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Tamer A. Mashtoly ◽  
Assem Abolmaaty ◽  
Mohamed El-Said El-Zemaity ◽  
Mohamed I. Hussien ◽  
Steven R. Alm

2001 ◽  
Vol 31 (6) ◽  
pp. 947-951 ◽  
Author(s):  
Marcio Voss ◽  
Robert Wayne Stefen Phillip Thomas
Keyword(s):  

A bioacumulação de metais por microrganismos se deve principalmente a fenômenos de superfície, ocorrendo adsorção, de forma estequiométrica, com os radicais aniônicos dos envoltórios celulares, seguido ou não de precipitação dos metais. Para estudar condicionantes da sorção de metais por bactérias vivas, quantificou-se o Cu2+ e Mn2+ retirados por um Bacillus sp. e uma Pseudomonas sp., isolados da rizosfera de trigo, de uma solução de cloreto dos metais, determinando-se a quantidade de metal restante no sobrenadante, após centrifugação. Usou-se delineamento experimental inteiramente casualizado, com três repetições. Ensaiaram-se efeito dos teores de Cu2+ e Mn2+, do pH e do tempo de crescimento bacteriano. O Bacillus sorveu mais Cu2+ e Mn2+ do que Pseudomonas. em todas as concentrações desses metais. A sorção de Cu2+ por ambas as bactérias apresentou maiores incrementos do que Mn2+ com aumento dos teores desses metais na solução. A alteração do pH 5,0 para 3,0 diminuiu a sorção dos dois metais. Com o tempo de cultivo de 90 horas a Pseudomonas apresentou maior sorção de cobre e de manganês do que no tempo de 16 horas. Os resultados obtidos assemelham-se aos fenômenos de troca de cátions em colóides.


2020 ◽  
pp. 1-4
Author(s):  
Opara C N ◽  
◽  
Anumudu C K ◽  

Lipases form an important group of relevant enzymes which have applications in various fields including; food, pharmaceutical, detergent, textile and cosmetic industries. Lipases can be produced from diverse sources including microorganisms. This study evaluated the potential of bacteria isolates from fresh-water clam Mercenaria Mercenaria to produce lipolytic enzymes. Ten samples of Clam (Mercenaria Mercenaria) were screened for the presence of lipase producing bacteria using classical culture methods. Eleven bacteria species were obtained, of which six (Actinomyces sp., E. coli, Bacillus sp., Pseudomonas sp., Clostridium sp. and Klebsiella sp.) produced lipases that had lipolytic activity in breaking down olive oil used in media supplementation. The best culture media and conditions for optimal production of lipases was studied and it was shown that supplementation of growth media with 2% dextrose at neutral pH gave the greatest yield of lipases when lipase producing isolates were grown in shake flasks. Measurement of biomass by culture and turbidimetric methods indicates that the highest cell mass was recorded by Pseudomonas sp at 7.8 x 105 CFU/ml, closely followed by Actinomyces sp. and Bacillus sp., at 6.2 x 105 CFU/ml and 5.3 x 105 respectively. The produced lipases were partially purified by precipitating with ammonium sulphate followed by dialysis. The total protein content of produced lipases was evaluated by the Lowry’s method, showing that estimated protein content followed the same trend as cell biomass with the highest recorded by Pseudomonas sp. at 1.53mg/ml, followed by Actinomyces sp. and Bacillus sp. at 1.47mg/ml and 1.32mg/ml respectively. The results obtained in this study shows that isolates obtained from freshwater clam can produce potent lipases which can be employed for industrial, food and other diverse uses


2016 ◽  
Vol 19 (1) ◽  
pp. 11 ◽  
Author(s):  
Wilis Arii Setyati ◽  
Ahmad Saddam Habibi ◽  
Subagiyo Subagiyo ◽  
Ali Ridlo ◽  
Nirwani S ◽  
...  

Pesatnya kegiatan budidaya perikanan dengan penerapan sistem intensif dalam beberapa tahun terakhir, telah memunculkan permasalahan berupa penurunan daya dukung tambak bagi kehidupan organisme budidaya. Dampak lanjut yang ditimbulkan adalah terjadinya serangkaian penyakit dan kerusakan kondisi lingkungan. Langkah antisipatif melalui penerapan bioremediasi merupakan solusi untuk mencegah kerusakan yang lebih serius. Dalam proses bioremediasi, enzim memainkan peran katalis yang mempercepat reaksi biokimia di kolam tanah dan air. Bakteri yang berasosiasi dengan spons memiliki beragam senyawa bioaktif yang dapat menghambat pertumbuhan bakteri patogen. Tujuan dari penelitian ini adalah isolasi dan skrining bakteri yang berasosiasi dengan spons yang memiliki aktivitas enzim ekstraseluler (proteolitik, amilolitik, selulolitik, dan lipolitik) dan aktivitas antibakteri, serta mengetahui interaksi sifat antagonisme antar isolat terbaik, dan identifikasi spesies bakteri secara fenotipik. Penelitian ini dilakukan dalam 4 tahap: koleksi sampel, isolasi, seleksi, dan identifikasi. Hasil penelitian menunjukkan bahwa total bakteri simbion spons yang diperoleh 15 isolat dengan potensi 15 isolat proteolitik, 12 isolat amilolitik, 12 isolat lipolitik, dan 4 isolat selulolitik. Terdapat 10 isolat memiliki aktivitas antibakteri terhadap Vibrio harveyi dan 2 isolat memiliki aktivitas antibakteri terhadap Vibrio alginolyticus. Isolat bakteri terbaik SP.1.3, SP.5.1, dan SP.5.3 tidak memiliki aktivitas saling antagonis antar ketiganya. Identifikasi fenotipik dari 3 isolat diduga bahwa isolat SP.1.3, SP.5.1, dan SP.5.2 diidentifikasi sebagai Bacillus sp., Acinetobacter sp., dan Pseudomonas sp. Kata kunci:  Bakteri simbion spons, enzim ekstraseluler, bioremediasi, vibriosis


2015 ◽  
Vol 39 (1) ◽  
pp. 167-176 ◽  
Author(s):  
Daniele Franco Martins Machado ◽  
Antonio Padilha Tavares ◽  
Sidinei José Lopes ◽  
Antonio Carlos Ferreira da Silva

Neste trabalho, o objetivo foi avaliar o efeito de isolados de Trichoderma spp. na emergência de plântulas e no crescimento de mudas de cambará (Gochnatia polymorpha). Utilizou-se, em casa de vegetação, substrato esterilizado e não esterilizado, sendo avaliados os efeitos de quatro isolados de trichoderma: TSM1 e TSM2 de Trichoderma viride, 2B2 e 2B22 de Trichoderma harzianum mais um mix preparado com a mistura desses quatro isolados, além de dois produtos comerciais à base de trichoderma. A análise dos dados permitiu concluir que os isolados de trichoderma testados não interferem na emergência das plântulas, mas os isolados 2B2 e 2B22 de T. harzianum apresentam potenciais como promotores de crescimento de mudas de cambará.


Economica ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 183-189
Author(s):  
Tamás Gáspár ◽  
Anita Dudás ◽  
Zsolt Kotroczó ◽  
Heléna Wass-Matics ◽  
Bence Trugly ◽  
...  

Az elmúlt évtizedekben a műtrágyák, növényvédő szerek, talajfertőtlenítők és más vegyipari agrokémiai termékek látványosan növelték a mezőgazdaság termelékenységét. Napjainkra a sokszor gondatlan és túlzott használat – pozitív hatásaik mellett – a talajok szerkezeti romlását, savanyodását, a talajélet nagyfokú csökkenését is magával hozta. A fenntartható szemléletű termesztéshez olyan mikrobiális oltóanyagok, bioeffektor termékek nagyobb fokú felhasználására van szükség, amelyek képesek javítani a növény mennyiségi és minőségi tulajdonságait. Munkánk során Európában már bevezetett kereskedelmi oltóanyagok alkalmazásának hatásait vizsgáltuk tenyészedényes kísérletben, három bioeffektor (BE) termékkel: BE1 - Trichoderma harzianum T 22; BE2 - Pseudomonas sp.; BE3 - Bacillus amyloliquefaciens Rhizovital 42 F1. Tenyészedényes kísérletben kerestük a termékek közti különbségeket, az alkalmazás módjától és idejétől, illetve a foszfor-formák felvehetőségétől függően is. A bioeffektorokat a gyártók által javasolt módon a vetéssel egy időben adagoltuk. Megállapítottuk, hogy azok a gyomok gyorsabb kelése miatt a gyomok biomasszáját növelték, megelőzvén a paradicsomot. A leghatékonyabbnak, a P-felvételt javítani képes BE 3 oltóanyag bizonyult. A bioeffektorok alkalmazásánál ezért a növény és az alkalmazott törzsek élettani igényei, potenciálja mellett a technológiai alkalmazási lehetőségeket is javasolt figyelembe venni.


Author(s):  
A. A. S. P. R. Andriani ◽  
Idris Sharif ◽  
Bohari M Yamin ◽  
S. A. M. P. Suryani ◽  
Krisnawan Kalimutu

Abstract. Although Trichoderma spp has been widely used in the SRI technique of rice cultivation the sources of Trichoderma that can adapt well to the local environment have been an interesting issue for quite some time.  It is commonly agreed that the local Trichoderma is much more preferred to be used for rice cultivation. In the present study, the Trichoderma from the soil of a rice field in Sukawati District,  Bali where conventional fertilizer and pesticide has been applied for a very long time was isolated.  After macroscopic observations (green color and sweet coconut smell ) the single isolated fungi have very much resembled Trichoderma Harzianum. 2 mL of the Trichoderma Harzianum solution was introduced in a plastic container containing 200 g half-boiled rice. After seven days the rice in the plastic appeared green. This sample will be used to produce more T. Harzianum for rice cultivation. One of the T.Harzianum treated rice hosts was coated with gold and subjected to SEM observation. Very high populated T. Harzianum fungi were observed. It was  dominated by hyphae. No conidia and conidiophores were spotted. Instead, quite a high density of spherical and oval shape spores was observed. Such a high density of T.Harzianum will certainly meet the requirement for an efficient application in the cultivation field. It would also be interesting to see the interaction between such a highly populated T.Harzianum  with other fungi or pathogens in understanding the role of Trichoderma as an antipathogen


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