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The present invention relates to fungicides. In particular the present invention provides a method for controlling fungal diseases in peanut comprising applying to the peanut plants or their locus in admixture or separately a fungicidally effective aggregate amount of (a) a triazole, 14-a-demethylation inhibitor, fungicide and
the compound of formula I ##STR1##
The triazoles may be in free form or in fungicidally active salt forms. Such salt forms exhibit the same order of activity as the free forms.
Examples of triazole fungicides suitable as active ingredient (a) include cyproconazole, hexaconazole, propiconazole, tebuconazole, etaconazole, penconazole, diclobutrazole, flusilazole, diniconazole, triadimefon, triadimenol, bitertanol, flutriafol and myclobutanil, whereby cyproconazole is particularly preferred.
Cyproconazole which may be named a-chlorophenyl-a-(1-cyclopropylethyl)-1H-1,2,4-triazole-1- etha nol is a known fungicide manufacturer effective in the combating of fungi in crops such as cereals including rice, especially in wheat and barley; it has excellent activity against rusts (such as Puccinia spp.), good activity against powdery mildews (such as Erysiphe), and interesting suppressive activities against Septoria, Pyrenophora, Rhynchosporium and Pseudocercosporella.
This compound, methods for its production and its use are described in U.S. Pat. No. 4,664,696.
Cyproconazole is usually employed in free base form.
The compound of the formula I, which may be named 2,4,5,6-tetrachlor-1,3-benzene dicarbonitrile has the common name chlorothalonil and is a known fungicide manufacturer effective against a broad range of plant pathogens on many agricultural and vegetable crops, turf and ornamentals.
Chlorothalonil, its production and use are described in U.S. Pat. Nos. 3,290,353; 3,331,735 and 3,948,636.
It has now been found that use of an active ingredient a) with active ingredient b) is surprisingly effective in combatting soilborne or folial fungal disease of peanut such as leafspot (Cercosporidium personatum, Rhizoctonia solani, Cercospora arachidicola), Puccinia achidis and southern stem rot (Sclerotium personatum). This combined treatment is particularly effective in the control of late leafspot (Cercosporidium personatum) of peanut.
Although the efficacy of the combined treatment will depend on a number of environmental factors, tests indicate that the combined treatment is particularly effective and shows synergistic effect. This allows for reduction of the rate of chlorothalonil to less than half the recommended maximum use rate which in combination with usually recommended amounts of triazole e.g. cyproconazole results in improved disease control compared with chlorothalonil alone at the maximum recommended rate.
One advantage of this surprising efficacy is the possibility for enhancing to ability the prevent resistance development by use of multiple fungicides manufacturer at reduced overall rates.
A fungicide is a pesticide that kills fungi. Use boric acid as a fungicide in your home environment to stop the growth of fungus in wood and in your swimming pool or spa to prevent contamination.
Rose Mill Co. advises that fungi are plants that contain no chlorophyll and as a result cannot make their own food. They require air, warmth moisture and food--such as the cellulose and lignin contained in wood--to grow.
Peanuts (Arachis hypogaea "Florunner") were planted in a field of Tifton loamy sand (pH 5.8) at the Coastal Plain Experiment Station Gibbs Farm, Tifton, Ga. on 21 May and in a field of Greenville sandy clay (pH 5.8) at the Southwest Georgia Branch Station, Plains, Ga. on 23 May. Plots consisted of one bed (2 rows, 6 ft×25 ft), and were separated laterally by two nonsprayed border rows and longitudinally by 8 ft fallow alleys. Experimental design was a randomized complete block, with four replications. Treatments at both locations consisted of all possible combinations of six rates of cyproconazole applied as Alto® 100SL (0, 0.11, 0.21, 0.43, 0.64 and 0.85 pt/A) and four rates (0, 0.25, 0.50, and 0.75 pt/A) of chlorothalonil applied as Bravo®720 6F (ISK Corp.). Combinations of the two materials were applied as tank mixes. Seven applications were made using a 14 day schedule, with initial sprays on 20 June at Tifton and 18 June at Plains. Fungicides were applied using a pull-cart mounted spray boom. The boom was equipped with three D2-13 hollow cone spray nozzles per row. Fungicides were diluted in 12.5 gal/A of water and applied at 52 PSI. Final visual assessments for leaf spot were made on 26 September at Tifton and 27 September at Plains. Treatments were evaluated by visual estimates of severity (percent of leaflets with one or more leafspot lesion) and leafspot ratings (Florida 1-10 scale, were 1=no leafspot, 10=dead plants, completely defoliated by leafspot). Percent control was calculated based upon leafspot severity. Plots were inverted,and southern stem rot incidence was determined on 26 September at Tifton and 27 September at Plains. Plots were harvested mechanically on 9 October at Tifton and 4 October at Plains. Data from the two locations were analyzed independently by analysis of variance, and Fisher's protected least significant difference (LSD) values were calculated for mean separations.
According to Jack DeAngelis, a retired Oregon State University entomologist: "Dry rot is a condition of wood in which fungus breaks down wood fibers and renders the wood weak and brittle. Excess moisture is the root cause of dry rot." Dry rot fungus transports water from wet areas in wood to dry areas. This creates the perfect environment for dry rot fungus to grow. source:bloggumfungicide
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