Pg. 46-49 Evaluation of prochloraz and fludioxonil fungicides, alone and in combination, to control post-harvest decay on litchi fruit

Prochloraz and fludioxonil alone and in different combinations were evaluated, as dip treatments in fungicide solutions at ambient temperature (22°C) and heated (55°C), for short (30 sec) and long (5 min) exposure times, for their ability to reduce post-harvest decay of litchi fruit. Fruit were stored at 3 ± 1°C (RH > 85%) for 40 days to simulate export conditions and thereafter at 10 ± 2° C in order to evaluate disease development during shelf life. The percentage disease free fruit at 0, 4 and 8 days after removal from storage at 3 ± 1°C were determined. Results showed that fungicide mixtures, sometimes at concentrations as low as 50% of individual fungicides, were the most effective to reduce post-harvest decay. A mixture of 405 ppm prochloraz and 300 ppm fludioxonil gave the best results, especially when fungicide solutions were heated and fruit were dipped for 30 sec. In general dip treatments in heated fungicide solutions for 5 min was less effective. Pericarp browning remained a problem on fruit in all treatments.