Explanation:

Ufra Disease a disease of deepwater rice caused by feeding damage of the nematode Ditylenchus angustus. As early as in 1913, Butler first reported this disease from Noakhali. Normally, the disease is observed in deepwater rice-growing areas such as Barisal, Dhaka, Sirajganj, Faridpur, Jessore, Khulna, Noakhali, Patuakhali and Sylhet districts. Susceptible varieties of rice suffer most.The ufra nematode feeds ectoparasitically on the inner surface of unmerged leaves, sheaths, buds, and developing panicles. Typical symptoms are a mosaic or chlorotic discoloration of emerging or emerged leaves; yellowish or pale green splash-patterns on affected leaves and sheaths; and appearance of brown to dark brown spots on leaves.