Diseases of fruit plantation medicinal and aromatic crops (2+1)

Alternaria rot

Causal organism: Alternaria alternata and A. Citri.

The first symptom of the disease is seen on the fruits as watery rot. The internal damage starts much earlier and which may vary from species to species. In lemon the pulp becomes greyish brown, soft and slimy. In oranges, grapefruits and mandarins, the affected interal tissues turn black giving a common name to the disease as Black rot or Black centre rot. In Mandarin, lesions often develop on the side of the fruit and the infected skin appears brown and hence the name, Brown spot of mandarins. In some cases, the symptoms consist of corky eruptions and pits.