Oomycetes fungicides

Table VIII Progress Achieved by the New Oomycetes Fungicides...

Since zoxamide has a different mode of action from other products used in the Oomycete market, there is no likelihood of cross-resistance to existing products such as metalaxyl, dimethomorph, cymoxanil or strobilurins. Consequently, zoxamide provides a unique tool for resistance management in the Oomycete fungicide market. 

The glyoxylic acid derivatives 53 (Fig. 18.10) were discovered by Bayer in 1994 as a new class of Oomycete fungicides by derivatization of advanced research project compounds with broad fungicidal activity [6]. 

Fluopicolide, a new Anti-oomycetes Fungicide with a New Mode of Action inducing Perturbation of a Spectrin-like Protein... 

The action of anti-oomycete fungicides on spectrin-like protein(s) localization was compared with that of fluopicolide. Different times of treatment were tested, from 3 min to 24 h. Figure 19.6 illustrates the results obtained after 2 h of treatment. None of the fungicides tested (iprovalicarb, fenamidone, dimethomorph, metalaxyl and zoxamide) induced spectrin-like protein redistribution. Unlike for... 

Fluopicolide-induced delocalization of spectrin-like proteins represents a new mode of action that is different to that of known anti-oomycete fungicides on the market. Spectrin-like proteins are poorly characterized in fungi and oomy-... 

One related compound, the corresponding sodium salt (fosetyl-sodium), also reached an advanced stage of development as an Oomycetes fungicide, however did not make it to market introduction. Moreover, other salts and the parent compound itself, ethyl phosphite or fosetyl, are also active against Oomycetes. 

Until about ten years ago, protectant foliar fungicides (such as ethylene bis-dithiocarbamates and phthalimides) and soil sterilants (such as vapam or methylbromide) were the only chemical means of controlling diseases caused by Oomycetes. These compounds are nonspecific biocides affecting many vital cell processes of both the pathogen and the host plant. This means that they are non-selective,... 

Within the past ten years, the market introduction of several new types of fungicides has significantly improved the prospects of controlling the Oomycetes. They belong to five different chemical classes the carbamates, the isoxazoles, the cyanoacetamide oximes, the etheyl phosphonates, and the acylalanines and related compounds. The chemical structures of those chemicals that have reached the commercial level are shown in Figures 3-5 (29, revised). Trade names, formulations and first reports are summarized in Table II (29, revised). The biological characteristics of these new fungicides and their impact on disease control have been reviewed by several authors (10, 16, 27, 28, 29, 33). 

In conclusion, all the new systemic fungicides against Oomycetes had an immediate need for mixing partners. It can be assumed that this will also hold true for future systemic fungicides. This use concept calls for flexibility both on the part of industry, national registration authorities, and the extension services to make safe and powerful products available for plant protection. 

Schwinn, F.J., Staub, T., and Urech, P.A. 1977. A new type of fungicide against diseases caused by Oomycetes. Meded. Fac. Landbouwwet. Rijksuniv. Gent 42, 1181-1188. 

Professor Schwinn discussed new advances in the chemical control of plant parasitic Oomycetes and Peronosporales. Some of the most devastating foliar and root diseases are caused by these fungi, hut they are often not controlled by systemic fungicides which control... 

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