The study of some plant extracts on tobacco Sore Shin disease

Tobacco Sore Shin caused by Rhizoctonia solani is an importatnt agent that distributed worldwide and causes yield losses in tobacco growing countries. One of the new methods of plant disease control is application of plant extracts. This research was performed to evaluate the antifungal activity of plant extracts on the causal organism of tobacco Sore Shin disease. The study was conducted on a completely randomized block design with 7 treatments and four replications in Tirtash Research and Education Center in 2014. Treatments included catmint, tobacco varieties (Burley21, K326 and Basma 178-2) extracts with concentrations of 2 per 1000, nicotine with concentrations of 1 per 1000, Thiophanate methyl fungicide with concentration of 25 gram in 100 liter water and the check sprayed with water. The results of variance analysis showed that the effect of plant extracts on control percentage of tobacco Sore Shin disease agent was significantly different at 1% probability level. Mean comparison of treatment showed that Thiophanate methyl fungicide, catmint and tobacco, Burley 21 cultivar extracts had the most effect in disease control with 84.95, 78.32 and 73.3 percent respectively. Therefore, the extracts of catmint and tobacco can be considered as natural fungicide for control of causal agent of tobacco Sore Shin.