Abstract
For application of sodium hypochlorite as a seed disinfectant to the control of bakanae disease caused by Gibberella fujikuroi in rice, we investigated the effects of sodium hypochlorite for antifungal activity, eliminating fungus from seeds and reducing disease occurrence in vitro and greenhouse. The viability of the pathogen was significantly reduced at $80{\mu}l/l$ concentration of sodium hypochlorite, and the pathogens did not grow at over $100{\mu}l/l$ concentration of sodium hypochlorite. The effect of eliminating fungus was 90% at treatment of 0.3% sodium hypochlorite solution to infected rice seeds for eight hours. When the rice seeds were soaked into 0.5% and 0.3% sodium hypochlorite solutions for twelve hours, the disease incidences of rice seedling were remarkably reduced to 4.3% and 4.7%, respectively, compared to 97.3% of non-treatment control. The rates of seedling stand were 29.1% and 26.9% higher with the sodium hypochlorite treatment than that of non-treatment control. When prochloraz and sodium hypochlorite was treated to naturally severely infested rice seeds with bakanae disease, the disinfection effect was higher than that of prochloraz alone treatment. When the seeds were soaked in sodium hypochlorite before or after prochloraz, the rate of seed contamination was low as 4.0% or 6.3%, respectively, compared to prochloraz alone as 13.7%. The disease incidence was low as 3.7% or 8.3%, respectively, compared to prochloraz alone as 14.3%. The disinfection effect of treatment with prochloraz after sodium hypochlorite was higher than that of treatment with prochloraz before sodium hypochlorite.
차아염소산나트륨의 벼 키다리병 종자소독제로서 활용 가능성을 구명하고자, 항균 활성 효과와 종자소독 효과를 연구한 결과, 차아염소산나트륨이 높은 항균 활성을 나타내어 $100{\mu}l/l$ 이상의 농도에서 균총이 형성되지 않았으며 $80{\mu}l/l$ 농도에서도 균 총형성이 현저히 낮았다. 벼 키다리병균 감염 벼 종자를 차아염소산나트륨 0.3% 농도로 8시간 침지 처리 시 종자소독효과가 90%로 높았다. 또한 차아염소산나트륨 0.5%, 0.3% 용액에 감염종자를 각각 12시간 처리하였을 벼 키다리병 발병율이 4.3%, 4.7%로 무처리 발병율 97.3%에 비해 현저히 억제되었으며, 유묘 출현율이 무처리 대비 29.1%, 26.9% 높았다. 그리고 벼 키다리병이 발생하여 자연 감염된 주남벼 종자를 사용하여 차아염소산나트륨 처리한 후 prochloraz 처리와, prochloraz를 처리한 후 차아염소산나트륨 처리의 종자 감염율이 각각 4.0%, 6.3% 로서 prochloraz 단독처리 13.7% 보다 낮은 경향을 보였으며, 벼 키다리병 발병율도 각각 3.7%, 8.3% 로 prochloraz 단독처리 14.3% 보다 낮았다. 아울러 차아염소산나트륨을 처리한 후 prochloraz를 처리한 것에서 더 높은 종자소독효과를 보였다.