Study on the infections status of Fusarium wilt disease of tobacco in Golestan province

Fusarium oxysporum f. sp. nicotianae, the causal agent of tobacco fusarium wilt, is one of the important agents that distributed worldwide and cause yield losses in tobacco growing countries. Control of this pathogen are accomplished through the use of chemical control, biological control, use of plant extracts, resistant cultivars and etc. The objective of this study was to evaluation of infections status of this disease in the tobacco fields of Golestan province. 45 tobacco fields in the five different villages of Gorgan region (Valeshabad, Taghartappeh, Jafarabad, Nodehmalek and Ghorogh) and the four different villages of Aliabad region (Baraftan, Pichakmahaleh, Elazman and Fazelabad) were selected in 2016 year. From the beginning of disease symptoms appearance, weekly surveys were done from fields and amount of disease incidence percent was recorded during the infection period. Statistical analysis were done using Stat Graphics Centurion XVI software. The results of this research showed that the based on the highest disease incidence there were no significant differences between regions, but there were significant differences (P<0.001) among fields. One field with disease incidence 48.2% in Valeshabad was highest disease incidence and combined Valeshabad with disease incidence 31.16% had the highest infection and Taghartappeh with disease incidence 18.5% had the lowest infection. Based on areas under disease progress curves, there no significant differences between regions, but there were significant differences (P<0.001) between fields. One field with under disease progress curves 1816.2 in Valeshabad had highest. In combined Valeshabad with 2700 had highest disease progress curves and Taghartappeh with 971.8 disease progress curves had the lowest. The results of this study show that Fusarium wilt disease of tobacco in all regions in Golestan province (Gorgan and Aliabad) with different rate of expansion.