‘Azhukal’ is a serious problem in cardamom plantations and is a major constraint in the successful cultivation of cardamom in Kerala and elsewhere. The disease is caused by Phytophthora nicotianae var. nicotianae and P. meadii. During heavy and incessant rainfall conditions, crop loss as high as 40 per cent occurs.
The disease is characterized by the formation of pale discoloured patches on the middle portion of the tillers, which lead to dry rot. As a result of the infection, the tillers become weak and break off at the point of infection. The partially broken tillers bend downwards and hang from the point of breakage (Fig. 5). When the infection occurs at the collar region, the tillers fall of giving a lodged appearance. In the affected tiller leaves and leaf sheaths dries off. Spraying with Bavistin (0.2 per cent) or Hexaconazole (Contaf) 0.2 per centcan manage the disease.