Storage rot of mango due to Rhizoctonia bataticola.
Sinha P., Pal R. K., Singh C. P., Agarwal D. K.
Author Affiliation: Division of Plant Pathology, I.A.R.I., New Delhi 110 012, India.
Annals of Plant Protection Sciences 11 : 329-332
Abstract : R. bataticola [Macrophomina phaseolina] was isolated from mango cv. Chausa fruits (collected in 2001-02) showing symptoms of rot. Mango fruits were surface sterilized with alcohol and inoculated aseptically with the fungus, and subsequently incubated for 24 h at 15, 20, 25, 28, 31 and 34°C. After 24 h, the fruits were stored under ambient conditions for 48 h. The efficacy of aqueous solutions of analytical grade potassium metabisulfite (KMS), sodium benzoate, sodium chloride and sodium bicarbonate at rates of 0.1, 0.2, 0.5 0.75, 1.0, 1.5 and 2% was tested against the pathogen. The effect of bavistin [carbendazim] 50 WP was also tested at rates of 0.003, 0.001, 0.05, 0.2, 0.5, 1.0 and 1.5%. Another set of experiments, comprising of sets A and B, was conducted. Fruits in set A were inoculated with the fungi, incubated at 30°C for 48 h and were dipped in bavistin at 0.05% and KMS at 1 and 2% before storage under ambient conditions. In set B, fruits were either not washed or washed in water and chlorinated water, before dipping in bavistin at 0.05% and KMS at 1 and 2%. Among the different aqueous solutions, only KMS showed toxic effects on the fungi (at 0.2%). KMS was 1000 times less toxic than bavistin against the fungi. Dipping in KMS 1 or 2% (without prior inoculation) was effective in controlling the pathogen, regardless of washing treatment. Bavistin 50 WP at 0.05% controlled the fungi on washed fruits only, but did not control the fungi on unwashed fruits. The ED50 and ED90 against the pathogen were estimated as 3460 and 10?100 µg/ml, respectively.