Study On Bioassay Method And Compound Of Jinggangmycin

Rice sheath blight caused by Thanatephorus cucumeris is one of the major rice diseases in the world. In Hunan Province, rice sheath blight is the main obstacle to limit high and rice, stable yield. In this study, different combined ratio of carbendazim, thiram, Manshui, Jinggangmycin were used to investigate their effecacy to rice sheath blight approved through the laboratory bioassay and field experiment . The results are as follows:1. In vitro stem with soaking is the best method for expression of the biological activity of Jinggang mycinThree bioassay methods mycelium growth inhibition test, in vitro stem absorption test and in vitro stem soaking Jinggangmycin were used to text activity of Jinggangmycin to T. cucumeris. The results showed that the Ec50 value of Jinggangmycin is largest for the in vitro stem absorbtion test, mycelium growth inhibition test is the second. The smallest Ec50 value is the in vitro stem soaked test, reflecting the field control of Jinggangmycin.2. In Laboratory test, this research studied the toxicity test of diferent pestiside The result indicate Carbendazim, Thiram and well-being of more than sheath blight fungus has a strong inhibitory effect, Ec50 values were 2.68μg/mL, 3.05μg/mL, 1.80μg/mL ,The values of two virulence factor were 164.9. The Ec50 value of the Jinggangmycin, Shui Po and the mixture were 17.94μg/mL, 0.1789μg/mL, 0.9727μg/mL, a total of two virulence factor of 1097.8, much better than the former mixture. Therefore choose Jinggangmycin Shui Po as a mixture of the field trial.3. The mixture of Man Sui and Jinggangmycin (M-J) has high effect to protect rice sheath blight, and is better than Jinggangmycin alone. when reduce the dosage, M-J has the same effect with Man Sui in a recommended amount. This also can save the costs and reduce pesticide pollution. Although the control effect of M-J 1 (87.5 %) is higher than that of the M-J 2 (84.6%), but for increasing rice production, B-J 1 is better than M-J 2. According to these results, we recommend that it is suitable to use M-J 2, (Man Sui mixed with Jinggangmycin by 1:100 of active ingredients), 50mL/667m2 , add water 50Kg for spraying.