Evaluation of the Rouin1 biological fungicide in management of Rhizoctonia root rot of sugar beet

In this study, the efficacy of the biological material named as Rouin1 based on Bacillus subtilis BS106 in controlling Rhizoctonia root rot disease of sugar beet was evaluated. The experiment was carried out as split plots in the pattern of randomized complete block design in two research farms in Kermanshah county. The major factor was seed coating with Rouin1 at various conditions. The minor factor was irrigating and not irrigating the plots with Rouin1 solution. All of the plants were inoculated with R. solani RS 124 inoculum 8 weeks after planting. The results of this study showed that major factor as seed coating had no effect on disease severity or crop yield in different forms, but minor factor as irrigating with bacterial solution reduced disease severity and increased crop yield at 1% probability level. By applying irrigation treatment of Rouin1 commercial material at the rate of 200 g/ha at two stages of 45 and 90 days after planting, the average disease index decreased from 4.4 (average control treatment) to 3.58 (average irrigation treatment). As a result, the disease index decreased by 0.82 units (approximately equivalent to 8.2% of the infection rate). Also, the average yield increased from 39,560 kg in the control treatment to 48080 in the irrigation treatment, which is equivalent to 17.72% of production increasing per hectare.