18.What are the symptoms of the black arms in cotton? [A] dark red to black lesions [B] dark brown to black lesions [C] dark green to black lesions [D] None of these
the black arm symptom is characterized by dark brown to black lesions which may coalesce and the extended necrosis then girdles the stem with blockage of the vascular system at infected sites which hinder the movement of water and nutrients though the plant system.
