What are the symptoms of sesame stem blight?

(Agricultural Wealth Network) Sesame can be affected by this disease throughout its life, but there are mainly two periods of damage: the first is from 3 to 7 days after emergence to the budding stage; the second is from topping to maturity. The disease symptoms are: at the seedling stage, the cotyledons turn yellow, and the roots become water-soaked and rot, causing death; after flowering, brown spots first appear on the roots and quickly become yellow-brown spindle-shaped patches girdling the stem. The edges of the lesions have no obvious boundary with healthy tissue, and the center of the lesion is grayish-white, densely covered with many small black granules. Because the cortex and phloem tissues of the roots and stems of diseased plants rot, leaving only fibers, they lose their conductive function and cannot absorb water and nutrients; the pith of the stem becomes hollow, and the stem breaks very easily.