Brown Spot of Rice
Large brown spots with a grey to white center appear on the leaves. The spots are surrounded by a yellow margin. As the disease progresses, whole leaves can turn yellow and die off. Brown Spot disease causes quantity and quality losses in the rice yield.
High humidity (86-100%) and relatively high temperatures (16-36°C) are favorable for the fungi. The pathogen is transmitted from plant to plant via air or through infected seeds. Therefore, the main sources of the dissemination include infected rice debris, seeds or weeds. The disease often occurs in unflooded fields with a lack of nutrients.
To be sure that the seeds are not contaminated, bathe them in hot water (53 - 54°C) for 10 to 12 minutes. To improve the results, place the seeds for 8 hours in cold water before the hot water treatment.
Treat seeds with fungicides containing Iprodione, Propiconazole, Azoxystrobin, Trifloxystrobin or Carbendazim.