Rice leaf blight disease symptoms appear 5-6 weeks after infection. The symptoms are:
1. Disease symptoms on rice leaves
(i) In the initial stage, wet, semi-transparent and elongated spots are formed on the leaves.
(ii) Wet spots 5-10 mm long are seen on petioles, main veins and margins.
(iii) The spots coalesce to form white or yellow striped spots.
(iv) The spots become progressively yellow and gray and become large in size. It is called Kresek.
(v) Diseased leaves gradually dry up and curl up.
(vi) Affected areas appear wavy.
(vii) White sticky sap accumulates on the leaves.
(viii) Milk-colored sticky droplets accumulate on the leaves in the early morning and later dry up to form small orange beads.
(ix) Diseased leaves dry up quickly and plants die.
2. Disease symptoms in rice seeds
(i) Attack of the disease occurs at the time of emergence of the rice grain.
(ii) The glume of paddy becomes scorched by water retention and becomes straw-like in colour.
(iii) Water-soaked small and round lesions are seen on infected paddy shoots.
(iv) Diseased paddy is sterile, the paddy is stunted and yield is reduced by 60%.
(v) Diseased rice grains do not bear fruit.