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Alvindia D.G.,Philippine Center for Postharvest Development and Mechanization PhilMech
International Journal of Pest Management | Year: 2013

An integrated approach using hot water treatment (HWT) and salt in the control of crown rot disease and preservation of quality in banana was investigated. The efficacy of HWT and either sodium carbonate (SC), sodium bicarbonate (SBC) or sodium hypochlorite (SH) applied alone or in combinations was evaluated against cultures of Lasiodiplodia theobromae, Thielaviopsis paradoxa, Colletotrichum musae and Fusarium verticillioides. The in vitro efficacy of salt was enhanced by 36.85-62.05% following HWT. Postharvest application, involving fruit dipped for 30 min in 1% (w/v) SC following HWT (50°C, 20 min), and storage for 14 d at 22-25°C and 90-95% relative humidity, maintained the overall quality of bananas and reduced the incidence of crown rot by 87.99%, which was comparable with that of treatment with fungicide at 89.60%. Other treatment combinations were capable of reducing crown rot to a lesser extent such as 80.64% by HWT + SH and 77.59% by HWT + SBC. Individual treatments were significantly lower at 70.07% for SH, 64.32% for SC, and 59.67% for SBC. HWT alone showed the lowest efficacy in controlling fruit decay at 52.15%. © 2013 Taylor & Francis. Source

Alvindiaa D.G.,Philippine Center for Postharvest Development and Mechanization PhilMech | Hirookab Y.,Tokyo University of Agriculture
Mycology | Year: 2011

Species of Clonostachys and Trichoderma isolated from the surface of bananas were highly antagonistic to crown rot- causing fungal pathogens of banana, such as Lasiodiplodia theobromae, Thielaviopsis paradoxa, Colletotrichum musae, and Fusarium verticillioides. Cultural and morphological examinations revealed that the fungal antagonists were similar to C. byssicola and T. harzianum, with some characters overlapping with closely related species.Molecular identification is recommended since the fungal isolates could not be differentiated adequately by cultural and morphological methods. Accurate taxonomy of these fungal antagonists was essential for the subsequent biological control studies. The tub2 region of β-tubulin genes of Clonostachys and 5.8S rDNA with the ITS regions of Trichoderma isolates were analyzed to determine their phylogenic placement. Molecular and phylogenetic analyses revealed 100% homology of Clonostachys (accession number AB308539) to C. byssicola (accession number AF358154) and 99% identity of Trichoderma (AB308540) to T. harzianum (accession number AY625068, AF443927). The identity of the fungal isolates was confirmed as Clonostachys byssicola Schroers and Trichoderma harzianum Rifai. © 2011 Mycological Society of China. Source

Alvindia D.G.,Philippine Center for Postharvest Development and Mechanization PhilMech
Crop Protection | Year: 2012

The efficacy of hot water treatment (HWT), as an alternative to chemical treatment, to control crown rot and maintain postharvest quality in cv. Buñgulan was studied. We examined the effects of hot water on mycelium growth and spore germination of Colletotrichum musae, Fusarium verticillioides, Lasiodiplodia theobromae and Thielaviopsis paradoxa, the most active crown rot-causing fungi involved in crown rot of cv. Buñgulan. HWT is ineffective in killing dormant spores of the pathogens but do cause a significant delay in mycelium growth and conidia germination. The optimum exposure for cv. Buñgulan is 50°C for 20min. Beyond this exposure, HWT caused fruit injury such as scalding, shriveling, and failure to soften. HWT delayed ripening and prolonged the green-life of fruit. It also improved the over-all appearance of banana, reduced weight loss, and improved firmness of the fruit. HWT lessened crown rot severity by 50% after 7 days and 33% after 14 days. © 2011 Elsevier Ltd. Source

Alvindia D.G.,Philippine Center for Postharvest Development and Mechanization PhilMech
Crop Protection | Year: 2013

The efficacy of Bacillus amyloliquefaciens DGA14, sodium carbonate (SC), sodium bicarbonate (SBC) and sodium hypochlorite (SH), applied alone or in various combinations, was evaluated invitro and invivo. DGA14 had variable responses in 1% (w/v) salts such as normal cell growth in SBC, reduction of cell cultivability by 1000-fold in SC and total inhibition by SH. DGA14 as stand-alone treatment controlled pathogens invitro by 70% while SC, SBC or SH by 20-45%. DGA14+SC restricted the mycelium growth of pathogens by 88%, DGA14+SBC by 83% and DGA14+SH by 52%. The efficacy of DGA14 against pathogens invitro was enhanced by 21% and 15% with the amelioration of SC and SBC, respectively. Postharvest application showed that fruit dipped for 30min in DGA14+SBC reduced crown rot by 93%, DGA14+SC by 70% and DGA14+SH by 9%. Our result indicates that the combination of B.amyloliquefaciens DGA14 with SBC managed crown rot disease comparable with synthetic fungicides without negative effects on fruit quality 14 days after treatment. © 2013 Elsevier Ltd. Source

Alvindia D.G.,Philippine Center for Postharvest Development and Mechanization PhilMech | de Guzman M.F.,Philippine Center for Postharvest Development and Mechanization PhilMech
Mycotoxin Research | Year: 2016

In 2012 to 2014, Philippine green coffee beans from Coffea arabica in Benguet and Ifugao; Coffea canephora var. Robusta in Abra, Cavite, and Ifugao; and Coffea liberica and Coffea excelsea from Cavite were collected and assessed for the distribution of fungi with the potential to produce ochratoxin A (OTA). The presence of fungal species was evaluated both before and after surface sterilization. There were remarkable ecological and varietal differences in the population of OTA-producing species from the five provinces. Aspergillus ochraceus, A. westerdijkiae, and Penicillium verruculosum were detected from Arabica in Benguet and Ifugao while Aspergillus carbonarius, Aspergillus niger, and Aspergillus japonicus were isolated in Excelsa, Liberica, and Robusta varieties from Abra, Cavite, and Davao. Contamination by Aspergillus and Penicillium species was found on 59 and 19 %, respectively, of the 57 samples from five provinces. After disinfection with 1 % sodium hypochlorite, the levels of infection by Aspergillus and Penicillium fell to 40 and 17 %, respectively. A total of 1184 fungal isolates were identified to species level comprising Aspergillus sections Circumdati (four species), Clavati (one), Flavi (one), Fumigati (one), Nigri (three), and Terrie (one). Within section Circumdati, 70 % of A. ochraceus produced OTA as high as 16238 ng g−1 while 40 % of A. westerdijkiae produced maximum OTA of 36561 ng g−1 in solid agar. Within section Nigri, 16.76 % of A. niger produced OTA at the highest 18439 ng g−1, 10 % of A. japonicus at maximum level of 174 ng g−1, and 21.21 % of A. carbonarius yielded maximum OTA of 1900 ng g−1. Of the 12 species of Penicillium isolated, P. verruculosum was ochratoxigenic, with a maximum OTA production of 12 ng g−1. © 2016 Society for Mycotoxin Research and Springer-Verlag Berlin Heidelberg Source

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