Sensibilidade de Metarhizium anisopliae à temperatura e umidade em três tipos de solos
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Data
2009-02-01
Autores
Lanza, Lourenço Maurício [UNESP]
Monteiro, Antonio Carlos [UNESP]
Malheiros, Euclides Braga [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Federal de Santa Maria (UFSM)
Resumo
Este trabalho teve como objetivo investigar o efeito da temperatura e do teor de umidade do solo na sobrevivência de Metarhizium anisopliae (Metsch.) Sorok. em três tipos de solos. Foram utilizados o Latossolo Vermelho textura argilosa, Latossolo Vermelho textura média e Argissolo Vermelho Amarelo textura arenosa média. As temperaturas empregadas foram 21,5; 26,8 e 31,5°C, e os teores de umidade foram 35, 65 e 100% de saturação. A sobrevivência do fungo foi avaliada após zero, 20, 40, 60, 80, 100 e 120 dias de incubação em cada temperatura estudada. Na análise do efeito do teor de umidade, a sobrevivência foi avaliada após zero, 14, 28, 42, 56, 70, 84, 98 e 112 dias de incubação à temperatura de 27,0±1,0°C. em ambos os ensaios, foi determinado o número de unidades formadores de colônias (UFC) em placa de Petri. Houve influência significativa da temperatura e do teor de umidade na sobrevivência do fungo. O maior crescimento e a maior sobrevivência ocorreram nas temperaturas de 21,5 e 26,8°C, enquanto que, no solo incubado a 31,5°C, o fungo cresceu pouco, e a população declinou rapidamente. No teor de 65% de umidade, houve rápido crescimento do fungo, mas no 112° dia foi observado um declínio da população nos três tipos de solos. Nos teores de 35 e 100% de umidade, o crescimento foi menor, mas obteve-se maior sobrevivência do fungo no solo.
The aim of this research was to evaluate the effect of soil temperature and soil water saturation on Metarhizium anisopliae survival in three soil types. The fungus survivorship was determined in the following soils types: Oxissol with clay texture, Oxissol with medium texture and Alfissol with medium sandy texture. The temperatures tested were 21.5; 26.8 and 31.5°C and the soil water saturation were 35, 65 and 100%. The fungus survivorship was evaluated at zero, 20, 40, 60, 80, 100, 120 days after soil incubation in each temperature accessed. In the assay for water saturation studies, the survival was evaluated after zero, 14, 28, 42, 56, 70, 84, 96, 112 days of incubation at 27.0±1.0°C. In both the assays, the colonies forming units (CFU) was determined in Petri dishes. The fungus survival was significantly influenced by the soil temperature and soil moisture. An increase in the number of CFU was observed in soil held at 26.8 and 21.5°C. The highest temperature (31.5°C) was more detrimental to fungus growth and survival than the lowest ones. The fungus grew quickly in the 65% soil water saturation but afterwards a decrease in the soil fungal population in the three soil types was observed. The 35 and 100% soil water saturations favored the fungus survivorship in the soil but was less favorable for the fungus growth.
The aim of this research was to evaluate the effect of soil temperature and soil water saturation on Metarhizium anisopliae survival in three soil types. The fungus survivorship was determined in the following soils types: Oxissol with clay texture, Oxissol with medium texture and Alfissol with medium sandy texture. The temperatures tested were 21.5; 26.8 and 31.5°C and the soil water saturation were 35, 65 and 100%. The fungus survivorship was evaluated at zero, 20, 40, 60, 80, 100, 120 days after soil incubation in each temperature accessed. In the assay for water saturation studies, the survival was evaluated after zero, 14, 28, 42, 56, 70, 84, 96, 112 days of incubation at 27.0±1.0°C. In both the assays, the colonies forming units (CFU) was determined in Petri dishes. The fungus survival was significantly influenced by the soil temperature and soil moisture. An increase in the number of CFU was observed in soil held at 26.8 and 21.5°C. The highest temperature (31.5°C) was more detrimental to fungus growth and survival than the lowest ones. The fungus grew quickly in the 65% soil water saturation but afterwards a decrease in the soil fungal population in the three soil types was observed. The 35 and 100% soil water saturations favored the fungus survivorship in the soil but was less favorable for the fungus growth.
Descrição
Palavras-chave
Biological control, Microbial control, ecology, Entomopathogenic fungus, Controle biológico, Controle microbiano, Ecologia, Fungo entomopatogênico
Como citar
Ciência Rural. Universidade Federal de Santa Maria (UFSM), v. 39, n. 1, p. 6-12, 2009.