Fitopatologia - Artigos
URI permanente para esta coleçãohttps://locus.ufv.br/handle/123456789/11741
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Item Use of Pochonia chlamydosporia to control Meloidogyne javanica in cucumber(Biological Control, 2014-02) Viggiano, José R.; Freitas, Leandro G. de; Lopes, Everaldo A.This study was done to evaluate the effect of the bionematicide Pc-10, based on Pochonia chlamydosporia var. chlamydosporia, on the control of Meloidogyne javanica. The fungus was applied by two methods: (1) drenching the substrate of seedlings with an aqueous suspension of Pc-10 (0, 4.5, 9.0, 13.5 and 18.0 g/L), or (2) incorporating Pc-10 into the soil of potted plants at a rate of 5000 chlamydospores/g of soil. The soil of each pot was infested with 3000 eggs of M. javanica, and one cucumber seedling was transplanted to each pot after 1 week. Increasing the doses of Pc-10 in the seedlings reduced the numbers of galls/g and eggs/g in the roots of cucumber plants in both experiments, regardless of the application method of the fungus in the soil. The application of 18 g/L of Pc-10 in the seedlings reduced the number of galls/g of roots by 46.04% and 49.44%, and the number of eggs/g of roots by 48.32% and 40.58% in the first and second experiments, respectively. Soil application of Pc-10 reduced the number of eggs/g of roots by 19.42% in the first experiment only. Drenching the substrate of seedlings with Pc-10 at 18 g/L controls M. javanica in cucumber and does not require additional fungus application in the soil.Item Screening of Pochonia chlamydosporia brazilian isolates as biocontrol agents of Meloidogyne javanica(Crop Protection, 2012-12) Freitas, Leandro G.; Dallemole-Giaretta, Rosangela; Lopes, Everaldo A.; Pereira, Olinto L.; Zooca, Ronaldo J. F.; Ferraz, SilamarPochonia species can occur in many Meloidogyne-infested soils throughout the world. The objective of this work was to isolate Pochonia species from different Meloidogyne-infested soil locations in Brazil and to screen for potential isolates effective in controlling Meloidogyne javanica under glasshouse conditions. A total of 29 isolates were identified as Pochonia chlamydosporia. Among them, 65.52% were identified as P. chlamydosporia var. chlamydosporia and 34.48% as P. chlamydosporia var. catenulata. For the glasshouse experiments, fungal chlamydospores were incorporated into the soil (5000 g soil^−1) and one tomato seedling was transplanted in 300 mL pot. After one week, each plant was inoculated with 1000 eggs of M. javanica. The isolates 1, 2, 3, 4, 9, 10, 21, 24, 28 (from Brazil) and 64 (from Spain) were the most efficient in reducing the number of eggs of the nematode. These isolates were re-evaluated in another glasshouse experiment, this time the number of eggs was increased (3000), inoculating both eggs and chlamydospores at the same time. After one week of inoculation, a tomato seedling was transplanted in each pot. In this experiment, isolates 64 and 10 were the most efficient in reducing the number of eggs by 72% and 60%, respectively.Item Pochonia chlamydosporia var. chlamydosporia (Goddard) Zare & W. Gams for the management of lettuce infected with Meloidogyne javanica (Treub, 1885)(Chilean journal of agricultural research, 2014-12-22) Viggiano, José R.; Freitas, Leandro G.; Lopes, Everaldo A.The application of the nematophagous fungus Pochonia chlamydosporia var. chlamydosporia (Goddard) Zare & W. Gams during seedling production of vegetable crops can be an efficient approach to control root-knot nematode. The aim of this study was to evaluate the effect of treating seedlings and/or soil with bionematicide (wettable powder formulation) based on chlamydospores from isolate Pc-10 on the Meloidogyne javanica (Treub, 1885) control in lettuce (Lactuca sativa L.). Isolate Pc-10 was diluted in water and applied when watering the seedlings (0, 4.5, 9.0, 13.5, and 18.0 g L -1 ) and/or to the potted soil (5000 chlamydospores g -1 ) used for growing lettuce. The soil in each pot was infested with 3000 M. javanica eggs. The number of M. javanica eggs was reduced in lettuce roots when isolate Pc-10 was applied either to seedlings or soil; there was no interaction between application methods. The decrease in the number of eggs was proportional to the increase of isolate Pc-10 applied to seedlings with maximum reduction of 43.5% at the 18 g L -1 dose. When the fungus was applied to the soil, the number of eggs was reduced by 12.3%. Increasing doses of isolate Pc-10 reduced the number of galls up to 21% with the 18 g L -1 dose. Applying bionematicide based on P. chlamydosporia isolate Pc-10 at 18 g L -1 on seedlings controls M. javanica in lettuce.