Stratego~(R) DC 250 - a new means of control for Pyricularia oryzae, Rhitoctonia solani, and other important rice-disease pathogens in Colombia

摘要

Among the cultivated cereal species rice is of increasing importance and is making an ever larger contribution to meeting the world's food requirements. In areas where this crop is grown intensively it is necessary to use appropriate technology and genetic material (appropriate varieties chosen and selected tor resistance or tolerance to the various pathogens encountered in rice). The crop should be sown at the optimal density, and good soil management and a balanced use of fertilizers are required.Proper use of water and other agronomic practices contributes notably to the control of the various crop-protection problems in rice, and, in particular, the pathogens that cause important diseases such as blast disease (Pyricularia grisea), leaf-sheathrot (Rhizoaonia solani and Acrocylin-drium oryzae), and grain spot (a fungal complex including Helminthosporium oryztie, Alternaria padwicki, Curvularia lunata, Fuxarium sp., etc.). These rice diseases, which are common in Colombia, were subject of control for various new fungicides of Bayer CropScience in various regions and locations over a period of 2 years. It was found that the new product Stratego~(R) DC 250 applied at rates of 0.1875-0.250 kg a.i./ha, corresponding to 0.75 to 1 litre commercial product/ha, can control most of these diseases very effectively. This new fungicide is a combination of 2 active ingredients: trifloxystrobin, a strobilurin of the new generation of "oximinoacetates", which acts by intervening in complex III, the coenzymeQcytochrome c reductase complex and so inhibiting electron transport across the mitochondrial membrane (such substances also being known as QoI products or quinone outside inhibitors), and the triazole propiconazole, a classic ergosterol synthesis inhibitor. New fungicides such as Stratego DC 250 are the result of intensive research and should be used in accordance with good practice guidelines as established in integrated crop management so that the effective lifecycle of the product is preserved foras long as possible.