These potato leaves display typical symptoms of early blight, which is caused by Alternaria solani. (photo: Francois van Deventer)
By Francois van Deventer:Technical product expert, fungicides and herbicides, Syngenta South Africa
Syngenta’s exciting new fungicide, MIRAVIS® Duo, originally made its market debut for exceptional preventative control of early blight (Alternaria solani) on potatoes. Since then, its label has been expanded to also include the control of early blight on tomatoes, and powdery mildew (Leveillula Taurica and Oidium neolycopersici) on both tomatoes and peppers.
Powdery mildew is rightly referred to as the dry-weather disease, due to the fact that its spores do not require free water to germinate. High humidity is sufficient. This characteristic explains why the disease is such a major headache on tomatoes and sweet peppers that are cultivated in tunnels or greenhouses.
Yield losses are directly correlated to the extent to which powdery mildew destroys photosynthesising leaf surface. In high-pressure situations, it can even cause leaves to die, resulting in as much as 50% of crops being lost.
Early blight on tomatoes is another disease of economic importance. It is caused by the fungus Alternaria solani – the same pathogen that causes early blight on potatoes. A. solani does require free water on the plant surface in order to infect it. Under favourable conditions, the disease cycle can repeat itself during the season, resulting in re-infection. The first signs of infection are small black or brown spots. As the lesions grow, the concentric circles that are so typical of early blight, become more visible. Lesions can develop on the leaves, stems or fruit and, depending on the location, cause severe foliage losses, premature weaning of fruit or damage to plant stems. In fields where the disease pressure had been particularly high, yield losses of almost 80% have been observed.
MIRAVIS® Duo is a combination of ADEPIDYN™ technology and difenoconazole, specifically formulated to provide excellent control of powdery mildew and early blight when applied correctly. MIRAVIS® Duo is recommended as a preventive treatment, given that ADEPIDYN™ technology has poor curative action.
Although the combination of different active ingredients in MIRAVIS® Duo helps with resistance management, the product should be used as part of a programme that includes active ingredients with different modes of action.
MIRAVIS® Duo is a superior product in an optimal formulation that guarantees easy and convenient use. The fact that it was extensively tested under a variety of conditions by Syngenta’s experienced team of local and international development researchers, assures producers of consistent results when MIRAVIS® Duo is applied correctly. In addition, clients can always count on the Syngenta commercial team’s expert advice.
READ THE PRODUCT LABEL FOR FULL DETAILS
MIRAVIS® Duo contains ADEPIDYN™ technology (pydiflumetofen) and difenoconazole (triazole) (Reg. no. L10750, Act 36 of 1947) HARMFUL.
MIRAVIS® Duo and ADEPIDYN™ technology are registered trademarks of a Syngenta Group company. Syngenta South Africa (Pty) Limited, Private Bag X60, Halfway House, 1685. Tel. (011) 541 4000.