Video narration
How can one brown spot on a rice leaf become the source of many more? Like mold spreading across damp bread, rice blast begins when a spore of Pyricularia oryzae lands on a moist leaf. Moisture helps it germinate. It forms an appressorium, a specialized structure that helps the fungus force entry through the leaf surface. Inside, the fungus spreads through the tissue until a blast lesion appears—the brown spot you notice. But that spot is not the finish. It is the launch point. The lesion produces new spores: this is sporulation. Wind, rain, or splashing water carries them across to new rice tissue. There, with suitable moisture, another spore germinates, penetrates, and starts a new infection. So, can one spot become an outbreak? Yes—when its lesion releases spores that reach new leaves nearby, the cycle begins again.