Abstract: To develop an effective preparation for controlling the base rot disease of Bambusa pervariabilis × Dendrocalamopsis grandis, the fungi were isolated from the rhizosphere soil of healthy bamboo by the dilution plate method. The strain RS05 was screened by the plate confrontation method and identified as Trichoderma spiralis by the morphological and molecular biological analyses. Based on the optimization of basic medium and fermentation conditions, the optimum carrier and additive of water-dispersible granule were screened. The results showed that the optimum medium for RS05 was PSA. The fermentation conditions were as follows: inoculation amount 8%, pH 6, fermentation time 6 d, 180 r/min, light culture at 26 ℃～27 ℃. The best prescription of water-dispersible granules were comprised 3% Tween 20 (wetting agent), 0.3% dextrin (UV protection agent), 3% soluble starch (binding agent), 5% sodium chloride (disintegrating agent), 0.3% calcium carbonate (stabilizer), 20% spore suspension, and silica gel (carrier) complemented 100%. The results of pot experiments indicated that the control effect of RS05 water-dispersible granules was higher than 88% when diluted less than 200 times, slightly higher than 86% of commercially available chemical preparations, and significantly higher than 64% of commercially available biocontrol preparations. In conclusion, the water-dispersible granules of T. spiralis RS05 has excellent control effect on the base rot disease of B. pervariabilis×D. grandis.

Key words: Trichoderma spiralis, water-dispersible granule, fermentation, control effect, base rot