Chemical control on the causal agent of tobacco blue mold disease

The Peronospora tabacina Adam fungi causes blue mold disease in the tobacco seedbed and fields. The purpose of this project was a survey of fungicides performance on the management of the tobacco blue mold. The experiments were carried out in the tobacco field with the cultivar HBT8 in 8×5 m plots with 8 treatments in 4 replications in a randomized complete block design in the village of Esbokola Sari (Mazandaran province) through 2019. Experimental treatments included fungicides: 1. Infinito (Propamocarb (62.5%)+ Flopicolide (6.25%) Infinfito, SC 68.75) at concentration of 0.5/1000, 2. Infinito at concentration of 1/1000, 3. Infinito at concentration of 1.5/1000, 4. Ridomil-mancozeb (metalaxyl) at concentration of 0.5/1000, 5. Ridomil-mancozeb at concentration of 1/1000, 6. Ridomil-mancozeb at concentrations of 1.5 /1000, 7. Dithane M45 at concentration of 2.5/1000, 8. control (spray with water). As the first symptoms of the disease was observed, spraying was performed and the results were compared with water control. The disease severity was assessed when the disease percentage in the control treatment was estimated at 50%. Design data was analysed with MSTAT-C software and mean comparison was done by LSD. The results of variance analysis showed a significant difference among the treatments at the 1% probability level. The fungicides of Infinito (1 and 1.5/1000), Ridomil-mancozeb (metalaxyl 1 and 1.5/1000), Dithane M45 (2.5/1000) and Infinito and Ridomil-mancozeb at concentrations of 0.5/1000 respectively, with 90, 88, 87, 82, 80, 75 and 70 percent controlled Tobacco blue mold disease in field. Therefore, fungicides of Infinito (1 and 1.5/1000), Ridomil-mancozeb (1/1000) are recommended for the management of Tobacco blue mold disease in field.