Traditional Fungicides Research Articles

Eco-efficiency improvement of a crop protection product: the perspective of the crop protection industry

The purpose of the underlying research for this paper was to obtain a better understanding of the eco-efficiency improvements of a crop protection product from the perspective of the crop protection industry in the context of sustainable agricultural development. The environmental impacts of an innovated and a traditional fungicide treatment were explored by applying two different product-oriented environmental life cycle analysis methods. One method (product life cycle-oriented energy balance) assessed the use of resources during the whole product life cycle, whereas the other method focused on the potential damage of the active ingredients for the environment and for humans. The functional unit and basis for comparison was defined as ‘treating 1 ha of citrus crop for foot- and root rot and trunk cankers’ during one crop season. Treatment with the innovated product resulted in relatively higher impacts per tonnage within the crop protection industry itself. However, outside the crop protection industry relatively fewer resources are needed and there are fewer potential releases into the environment. The innovated product fulfills its function more eco-efficiently or more sustainable than the traditional product.

Evaluation of Electrolyzed Oxidizing Water for Management of Powdery Mildew on Gerbera Daisy.

Powdery mildew has been a major concern for greenhouse growers. Acidic electrolyzed oxidizing (EO) water was evaluated for the management of powdery mildew on gerbera daisy. EO water significantly reduced percent powdery mildew when sprayed twice a week and when sprayed every other week, alternating with fungicides. Studies were completed to determine if EO water could be used in an integrated management system. EO water was compatible with several fungicides and insecticides in an in vitro assay. However, EO water was not compatible with thiophanate methyl at the full rate and acephate at both the half and full rates. EO water is a viable option for controlling powdery mildew on gerbera daisies and provides growers an additional tool to reduce the use of traditional fungicides in greenhouses.

Evaluation of Biorational Products for Powdery Mildew Management in Cornus florida

Abstract Between 1997 and 1999, 21 biorational products were evaluated for powdery mildew control on dogwood seedlings and compared with the traditional fungicides Banner® (propiconazole), ConSyst™ WDG (chlorothalonil and thiophanate methyl) and Cleary's 3336 F® (thiophanate-methyl) in a shadehouse environment. Selected products were also evaluated in rotation with Banner®, where Banner® application was made once for every three applications. Among the biorational products the household soaps, Palmolive®, Ajax®, and Equate®, the potassium bicarbonate salt Armicarb™, and the antitranspirant Vapor Gard® were most effective in reducing powdery mildew severity. However, Vapor Gard® stunted plant growth, and Palmolive® caused some phytotoxicity. While Safer Soap®, M-Pede®, Triact™, Neem Gold®, Kaligreen™, and Ultrafine® oil were not as effective in controlling powdery mildew as the fungicides, the increase in plant growth was similar. Spray regimes that included the biorational and Banner® generally gave better disease control and enhanced plant growth over the biorational products alone. While Banner® and ConSyst™ were highly effective in controlling powdery mildew, Cleary's 3336 F® gave inconsistent results and proved only moderately effective. Overall, plant growth correlated negatively with powdery mildew severity for the biorational products (r = −0.58) and biorational/Banner rotation (r = −0.54).

Hydroxyl radical scavengers inhibit sclerotial differentiation and growth in Sclerotinia sclerotiorum and Rhizoctonia solani

The effect of hydroxyl radical scavengers dimethyl sulphoxide, p-nitrosodimethylaniline, ethanol, benzoate, salicylate and thiourea was studied on sclerotial differentiation and growth of Sclerotinia sclerotiorum and Rhizoctonia solani. There is a correlation between both scavenger concentration and scavenger-hydroxyl radical reaction rate with delay and inhibition of differentiation at growth-noninhibiting scavenger concentrations. Growth-inhibiting scavenger concentrations further increased delay and inhibition of differentiation, and eventually stopped fungal growth, acting as antifungal antioxidant alternatives to traditional fungicides. p-nitrosodimethylaniline (with the highest hydroxyl radical reaction rate) was the most effective inhibitor of sclerotial differentiation and growth. The results strongly support the theory that oxygen free radicals induce differentiation in sclerotium-producing phytopathogenic fungi.

Hydroxyl radical scavengers inhibit lateral-type sclerotial differentiation and growth in phytopathogenic fungi

The effect of certain hydroxyl radical scavengers (dimethyl sulfoxide, p-itrosodimethylaniline, ethanol, benzoate, salicylate and thiourea) was studied on lateral sclerotial differentiation and growth of Sclerotium rolfsii and Sclerotinia minor. At low growth noninhibiting scavenger concentrations there was a scavenger dose-and reaction rate-correlation with increased sclerotial differentiation delay and inhibition. Higher scavenger concentrations further inhibited sclerotial differentiation and finally arrested growth, providing antioxidant antifungal alternatives to traditional fungicides. Salicylate and pnitrosodimethylaniline (with the highest hydroxyl radical reaction rates) were the most effective inhibitors of sclerotial differentiation and growth. These data strongly support our theory which suggests that oxygen free radicals are responsible for sclerotial differentiation in fungi.

Sclerotial development, melanin production and lipid peroxidation bySclerotium rolfsii

Melanin pigments constituted 13.9% (W/W) of sclerotial walls ofSclerotium rolfsii. The lipid and ash contents in sclerotial walls were twice those in hyphal walls of the fungus. Progress in culture age and maturation of sclerotia were always accompanied by increased levels of lipid peroxidation products and melanin. Lipid peroxidation and melanin formation may thus proceed in parallel during sclerotial biogenesis and maturation. Both these processes are strongly affected by Fe2+ and by antioxidant vitamins (ascorbic acid), microelements (selenium) and mercapto compounds (glutathione). Myceliogenic germination and lytic activityvia melanin production can thus be affected by (anti)oxidants that could potentially be used for controlling sclerotia-producing fungi without using traditional toxic fungicides.