Journal of Food, Agriculture and Environment

Vol 11, Issue 1,2013
Online ISSN: 1459-0263
Print ISSN: 1459-0255

Compatibility of entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin with fungicide thiophanate-methyl assessed by germination speed parameter


Carlos Eduardo S. Fabrice 1, Rafael L. Tonussi 1, Ravely C. Orlandelli 1, Daniela A. L. Lourenço 2, João Alencar Pamphile 1*

Recieved Date: 2012-08-29, Accepted Date: 2013-01-12


The biocontrol agent Metarhizium anisopliae is efficient to combat more than three hundred species of insect pests and can be used in biological- chemical combinations with chemical defensives maintaining the inoculum source of fungi in the field. Studies of conidiogenesis in M. anisopliae are fundamental, considering that conidia are the main form of inoculum for biological control. Among the pesticides applied in pastures for pest control, to prevent and control plant diseases, is thiophanate-methyl. Due to the importance of M. anisopliae as a microbial agent of a wide variety of insect pests, it is of critical importance to evaluate the effect of chemical products on this fungus, considering the conidia germination speed parameter, which is directly associated with virulence. Therefore, this study aimed to verify the effect of different concentrations of thiophanate-methyl on the conidia germination speed of MT (Mato Grosso) strain of M. anisopliae. Conidia were incubated with thiophanate-methyl in concentrations of 200 µg/ml (T1), 20 µg/ml (T2), 2 µg/ml (T3) and 0.2 µg/ml (T4) at 28ºC and sampled throughout 24 hours. The control was performed without the pesticide. Bayesian analysis showed an inhibition of conidia germination in the presence of 200 and 20 µg/ml of thiophanate-methyl. The curve of conidia germination speed showed that until 14 h of incubation, there was an increase in the germination speed of control and all treatments. Shortly afterwards, this speed decreased in T2 and T3 but it remained stable for C and T4. A stronger inhibition of conidia germination was caused by T1. The compatibility observed in concentrations of 20 and 2 µg/ml indicates that this fungicide could be mixed with M. anisopliae in biological-chemical combinations, maintaining the viable fungal inoculum after its application. To confirm it, third-instar larvae of sugarcane borer (Diatraea saccharalis) were infected with a combination of a conidia solution of MT strain and thiophanate-methyl in concentration of 20 µg/ml. As controls, water, conidia solution and the fungicide were applied separately. Food was offered ad libitum and larvae were monitored daily throughout 7-12 days at 25ºC and the factors of living larvae, larvae in pupal stage and dead larvae were evaluated. As results, the thiophanate-methyl did not affect the D. saccharalis larvae, but when these larvae were treated with M. anisopliae conidia mixed with the pesticide, it was observed a reduction of larvae mortality of 26.8% when compared with the use  of M. anisopliae only (without pesticide). 


Vegetative development, biological-chemical combinations, entomopathogen, conidia, Bayesian analysis, biological control, sugarcane borer, pupal stage, mortality

Journal: Journal of Food, Agriculture and Environment
Year: 2013
Volume: 11
Issue: 1
Category: Agriculture
Pages: 368-372

Full text for Subscribers

Note to users

The requested document is freely available only to subscribers/registered users with an online subscription to the Journal of Food, Agriculture & Environment. If you have set up a personal subscription to this title please enter your user name and password. All abstracts are available for free.

Article purchasing

If you like to purchase this specific document such as article, review or this journal issue, contact us. Specify the title of the article or review, issue, number, volume and date of the publication. Software and compilation, Science & Technology, all rights reserved. Your use of this website details or service is governed by terms of use. Authors are invited to check from time to time news or information.

Purchase this Article:   20 Purchase PDF Order Reprints for 15

Share this article :