Abstract:

In order to screen the effective fungicides applicable for control of litchi pepper spot disease and for green food production, the field experiment was carried out to evaluate five fungicides, focusing the control effect on litchi pepper spot disease and postharvest preservation potential. The results showed that the treatments of kasugamycin 5%+copper oxychloride 45% WP at dilution ratio of 500-fold and kasugamycin 4.5%+oxine-copper 40.5% SC at dilution ratio of 1200-fold had optimal field control effects at 74.25%-87.48% after being applied preventatively for three to four times, and control effects of four times of application were much better than that of three times. The control effects of two treatments still reached 73.10%-76.27% on 5^th day of storage, indicating the good postharvest preservation effect. In contrast, although the 750-fold solution of 50% chlorobromoisocyanuric acid SP had a certain field control effect (66.18 % -68.77%), the control effect decreased rapidly to less than 22 % during postharvest storage. Bacillus subtilis 100 billion CFU/g WP at dilution ratio of 750-fold and kasugamycin 2% AS at dilution ratio of 400-fold had poor control effect at less than 52% both in the field and in the postharvest storage period. In conclusion, the study showed that kasugamycin 5%+copper oxychloride 45% WP and kasugamycin 4.5%+oxine-copper 40.5% SC could be the valuable potential fungicides for controlling litchi pepper spot disease.

Key words: litchi pepper spot disease, control effect, Bacillus subtilis, kasugamycin, copper oxychloride, oxine-copper, chloroisobromine cyanuric acid