APS Abstract of Presentation

Control of black rot of pineapples with calcium oxide
R. CARVALHO (1)
(1) EMEPA (Empresa Estadual de Pesquisa Agropecuária da Paraíba) - João Pessoa - Paraiba - Brazil
Phytopathology 98:S31

The black rot of pineapple (Ananas comosus var. comosus) is an important post-harvest disease which is common in almost all producing areas of the world. It is caused by the fungus Chalara (Thielaviopsis) paradoxa which penetrates mainly through wounds made on the fruit base during harvest. Infection is rapidly followed by large dark lesions and by a huge rot which characterize this disease. Different from other pineapple pests and diseases which are treated with pesticides some months before the harvest, the control of black rot of pineapple requires the application of fungicides immediately after the harvesting process, leaving a short time between spraying and consumption with high risks of contamination. This work had the objective of studying the effect of alternative products on the control of this disease, including the use of liquid wax, tannins, citrus extracts, food preservatives (used in bakery and fruit juice industries) and calcium oxide (lime). This research was carried out at the Pineapple Research Station in Sapé, Paraíba, Brazil, in 2007, in a completely randomized experimental design. Most of the alternative products were incapable of preventing the development of the disease. However, it was found out that the use of calcium oxide (lime) applied as a paste as well as in a powdered form did not allow the establishment of the disease nor the development of lesions. Therefore, this research has shown that an environment friendly alternative control of black rot of pineapple can be achieved by using only calcium oxide (lime). Furthermore, since each pineapple fruit must be individually sprayed with chemical fungicides immediately after harvesting in order to prevent infection through the wounds, this lime approach will avoid the risk of contamination to consumers, besides being an old technique turned into a rediscovered contribution to a modern integrated Phytopathology.