Zoology - Biotechnology and Its Applications Question with Solution | TestHub

Citrus canker is a bacterial disease. It is caused by bacteria Xanthomonas citri which is aerobic, rod shaped and monotrichous. It is a world wide disease of most Citrus plants but the most susceptible are grape fruits, sweet orange, lime and lemon. The symtoms first appear on the undersurface of leaves as small watery slightly raised, round light green spots that finally rupture to form corky crater like lesions or canker. Twigs, fruits, also develop lesions. The disease reduces the quantity and quality of fruits. Powdery mildew is caused by Erysiphe sp, red rot of sugarcane by Colletotrichum falcatum and wilt disease by Fusarium sp. Thus, they are all fungal diseases.