Bacterial Leaf Blight| बॅक्टेरियल लिफ ब्लाईट
Bacterial blight is caused by Xanthomonas oryzae pv. oryzae. It causes wilting of seedlings and yellowing and drying of leaves.
Wilting and yellowing of leaves, or wilting of seedlings (also called kresek). On seedlings, infected leaves turn grayish green and roll up. As the disease progresses, the leaves turn yellow to straw-colored and wilt, leading whole seedlings to dry up and die.
On older plants, lesions usually develop as water-soaked to yellow-orange stripes on leaf blades or leaf tips or on mechanically injured parts of leaves. Lesions have a wavy margin and progress toward the leaf base.
On young lesions, bacterial ooze resembling a milky dew drop can be observed early in the morning. The bacterial ooze later on dries up and becomes small yellowish beads underneath the leaf.
Bacteria Xanthomonas oryzae pv. Oryzae cause the disease.this is a rod shaped bacteria, germ negative and optimum temperature for growth is 25-300 C. Motility of the bacteria is by a single polar flagella. Development of the favored by temperature above 250 C. severe kresek development occurs at temperature 30-350 C (Maximum) and 24-260C (Minimum) and RH at 64-84%. Seed is the major is the source of primary inoculum.