Abstract:
Leaf and nut blight (Cryptosporiopsis sp.) of cashew is a very common and destructive
disease in Tanzania. Symptoms coincide with flushing of shoots and flowering from July to
December. Cashew leaf and nut blight infects young tender shoots, pseudo-fruits and nuts. Initially,
the disease appears in the form of small, scattered brown spots on the leaf lamina. Later, these spots
increase in size and coalesce covering larger leaf area, with dark brown margin. The first symptoms
of the disease are chlorotic spots on both sides of the youngest tender leaves. Leaf spots vary in
size, shape and colour between different varieties of cashew. The spots are brown, with a dark
brown border, spreading necrotic lesions leading to leaf blight; circular, irregular or angular 1–2 cm
in diameter; irregular roughened or corky lesions with eruption and necrosis of epidermal tissue,
sometimes localized along veins. The diseased leaves curl and can be totally defoliated.
