Abstract only

Lack of attention towards seed treatment in recent years caused wide expansion of wheat diseases such as common bunt, fusariosis and helminthosporiosis root rotes. This effect is observed as in Georgia so in other CIS countries (Abelenzev, 1997; Pavlova, 1998). We have focused on new seed treatments of the triazole group: Dividend (diphenoconazole), Raxil (tebuconazole), Premis (trityconazole), blend pesticide Vincit (jlutriaphole + thibendazole) and Kolfugo (carbendazime group). Data on effectiveness of the above listed treatments is found in papers of Bolbat et al. ( 1997), Pavlova (1998), Chulkin et al. (1997) and others. We have carried out laboratory and field tests of these pesticides on seeds of the winter wheat variety Bezostaja 1. Field tests were carried out at the Martkopi experimental station of the Georgian RI of Plant Protection. Tests were performed as in the natural environment, so at the sites artificially infected by spores of common bunt. Fungitoxic effect of pesticides was investigated on germination of spores in laboratory environment (Golyshin, 1970). TMTD served as a model and distilled water as check. LC50 (lethal concentration) rates were determined. The following LC50s rates were recorded for fusarium: Dividend 0,008; Premis 0,03; Vincit 0,006; Kolfugo 0,002; TMTD 0,0025; for spores of common bunt: Dividend 0,0006; Premis 0,0035; Vincit 0,004; Kolfugo 0,003; TMTD 0,02. Thus, the high toxicity of Dividend towards spores of common bunt was ascertained. Grain germination ratio 93% was registered upon treatment with Dividend. The shoots developed intensively and were of distinct dark-green color. At the infected sites in field conditions the portion of seeds infected by common bunt was as high as 40% in cases when the chemical treatment was not used. In variant with Kalfugo Super and Raxil treatments only 3% of seeds were infected, while at Dividend treatment development of common bunt was not observed. In field conditions Dividend showed high effectiveness as well. The data on biological and economic effectiveness of some seed treatment chemicals is quoted in the table below. The effect of Dividend on yield was a combined result of extinction of pathogens and direct positive influence of the chemical on the growth and development of winter wheat. "Ecotox rating" (Melnikov, Belan, 1998) of Dividend is 0.0017, while that of TMTD is 0.019. This fact proves the undoubted advantages of Dividend as of environment-friendly and economically efficient wheat pesticide. New chemicals of the triazole group and some blend seed treatments proved their high effectiveness in control of the pathogens found as at the surface or inside the grains, so in soil.

English

0409|AGRIS 0401|AL-Wheat Program

Juan Carlos Mendieta

CIMMYT Publications Collection