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XSGrowth Home Fungicides An Insight Into Quinone Outside Inhibitor (QoI) Fungicides

An Insight Into Quinone Outside Inhibitor (QoI) Fungicides

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M. P. Srivastava, FNAS, Chairperson, International Working Group on Plant Health Clinic

Quinone outside inhibitor fungicides are synthetic derivatives of naturally occurring strobillurin compounds introduced in the late 1990s and represent a novel group of fungicides, highly active against a broad range of fungi belonging to Oomycetes, Ascomycetes, Basidiomycetes and Deuteromycetes. They are mitochondrial respiration inhibitors (MRI) which inhibit fungal respiration at the Quinone “Outside” (Qo) binding site of the cytochrome bc 1 complex. Being site-specific, they are at risk from the development of resistance in the target plant pathogens.

QoIs are not cross resistant with other fungicide groups, but there is a cross resistance among all active ingredients within QoI group which includes azoxystrobin, kresoxim-methyl, demoxystrobin, fluoxastrobin, metaminostrobin, orysastrobin, picostrobin, pyraclostrobin, trifloxystrobin, and the non-strobilurins, famoxadone (oxazoldinone compound/oxazole fungicide) and fenamidone (imadizilinone compound/imadizole fungicide). QoI group of fungicides were previously known as STAR (Strobilurin-Type Action and Resistance/ Strobilurins And Related compounds) fungicide.

In order to minimize the likelihood of resistance development, resistance guidelines provided by FRAC must be followed, which involves following key points:
•    In cereal crops the number of QoI containing sprays must not exceed two.
•    QoI products must always be used in combination with a product, other than QoI, recommended for the control of same disease.
•    QoI product should be used preventively or as early as possible in the disease cycles keeping aside reliance on curative ability.

It is therefore vitally important that all users of QoI fungicides adhere to the latest resistance management guidelines for cereal and other crops available from FRAC. For latest updates, consult the web page, http://www.frac.info/.
Some solo and coordinated products commercially developed for various QoI fungicides are given below:


Commercially available QoI fungicides

Company / Common Name                 
Solo Product
Coordinated Products




Abound, Amistar, Heritage,                     


Uniform (azoxystrobin + mefanoxam)

Quilt (azoxystrobin + propiconazole)

Quadris Opti (azoxystrobin + chlorothalonil) 

Du Pont


Famoxate Tanos 50 DS (famaxadone + cymoxanil)

Bayer CropScience



Reason, Fenstar

Fenomen, Sonata, Sereno 


Arysta LifeScience


Disarm, Evita  






Sygnus, Sovran, Stroby  

Collis (kresoxim-methyl + boscalid) 

Allergo (kresoxym-methyl + epoxiconazole) 

Bayer CropScience






Du Pont






Cabrio, Headline, Insignia


Pristine (pyraloclostrobin + boscalid)

Bayer CropScience


Compass, Flint, Gem, Twist   Stratego (Trifloxystrobin + propiconaz 

1 Excellent against Blast of rice

2 Recommended against Blast and Sheath blight of rice

Last Updated on Monday, 06 July 2009 06:49  


International Technological Achievements Award Conferred on Dr. M. P. Srivastava

Global consultant on plant health and former Director Planning & Head, Plant Pathology of Haryana Agricultural University, Prof. M.P. Srivastava has been bestowed upon with “International Technological Achievements Award” on February 9, 2014.

Photo: Dr M P Srivastava [Extreme R] receiving the award

The award was given in recognition of his internationally acclaimed contribution on Plant Healthcare Technology and its dissemination towards mitigating crop losses and promoting plant health clinic worldwide. The award instituted by EET CRS, was given to him by presenting a memento and Certificate of Excellence in a glittering function in Noida on 9th of February 2014. Dr Srivastava has shared his innovations in reducing crop losses and strengthening food security at several occasions in India and at International Congresses at Edinburgh 1998, New Zealand 2003, Beijing 2013.