| Objective:To control branch wilt disease in Lonicera japonica Thunb.with safe and effective fungicides,fungicide screening experiment was carried out following quality analysis of Flos Lonicerae.Methods:Proper fungicides were screened through the inhibition effect of honeysuckle branch wilt fungus in laboratory and the controlling effect in the field.Quality test of honeysuckle and honeysuckle stem from different fungicide treatments was conducted according to the honeysuckle and honeysuckle stem detection method in the China pharmacopoeia(2015 edition).Two broad-spectrum fungicides,tebuconazole and difenoconazole,were used in Lonicera japonica Thunb.for root irrigation treatment in this study.Recommended dose,double recommended dose of fungicides for twice and triple times were used to control the disease and the final fungicide residues were analyzed post 15 days of the last irrigation.Results: 1.Fungicide screening and their control effects on honeysuckle branch wilt diseaseThe honeysuckle wilt branches were placed in the bottle with fungicide.The better effects of different fungicides to the fungus causing honeysuckle wilt branch disease were from the treatments with 10% difenoconazole WG of 6000 times,25% tebuconazole WP of 1200 times,30% hexaconazole WP of 2500 times.Three kinds of fungicides were used in honeysuckle field with irrigation in the root,which was 10% of difenoconazole WG of 4000 times,25% tebuconazole WP of 1000 times,30% hexaconazole WP of 2000 times.The honeysuckle branch wilt disease was investigated fifteen days post fungicide treatment.The control effect of three kinds of fungicides was 66.67%,61.90% and 76.19%,respectively.The best controlling effect is from the treatment with 25% tebuconazole WP of 1000 times(97.56%),with significant difference.The controlling effect from 10% difenoconazole WG of 4000 times was 58.56%,which was reduced compared with controlling effect from 15 d post applying fungicide.Under different fungicides treatments,the production of honeysuckle with 25% tebuconazole WP of 1000 times was 11.179 g/strain,which was higher than other treatments.Yield of honeysuckle varied in fungicide treatment of honeysuckle branch wilt disease,but the difference was not remarkable.2.Fungicide residue detection in honeysuckleFungicide residues in the samples were detected using LC-MS8050.Difenoconazole detection is based on the standard SN/T 1975-2007,with the detection limit 5.0 ?g/kg.Tebuconazole and hexaconazole detection are based on the standard GB/T 20769-2008,with the detection limit 0.56 ?g/kg.According to the results,the residues of fungicides in this study was not detectable.In different doses of honeysuckle healthy plants,difenoconazole residues were not detected in the first batch of flowers in each treatment.The residues of tebuconazole in the second batch of flowers was 0.14 0.22 mg/kg.The residues of tebuconazole from the treatment of 25% tebuconazole WP of 1000 times in root for 2 times,3 times were 0.14 mg/kg and 0.16 mg/kg,respectively.The residues of tebuconazole from the treatment of 25% tebuconazole WP of 500 times in root for 2 times,3 times was 0.16 mg/kg and 0.22 mg/kg,respectively.3.The quality detection of honeysuckle and honeysuckle stemThe chlorogenic acid and luteolin-7-O-glucoside were detected which represent the quality of honeysuckle stem according to the Chinese pharmacopoeia(2015 edition).The results show that in Feng Qiu,the highest content of chlorogenic acid was in the healthy plants CK(2.298%).There was no significant between 30% hexaconazole WP of 2000 times(2.284%)and strain(2.283%)in the control group in chlorogenic acid content in the bud.The content of chlorogenic acid in Flos Lonicerae with 10% difenoconazole WG of 4000 times handling was the lowest(1.922%).The content of luteolin-7-O-glucoside in the healthy plants CK was the highest(0.0522%),and 25% tebuconazole WP of 1000 times(0.0431%),30% hexaconazole WP of 2000 times(0.0411%),the disease plants CK(0.0417%)the content of luteolin-7-O-glucoside,which had no significant differences,but lower than that of healthy plants CK.In Yuan Yang areas honeysuckle chlorogenic acid content was higher than that of healthy plants CK(0.140%),chlorogenic acid content of the honeysuckle with drugs was higher than the disease plants CK(0.206%),dealing with 25% tebuconazole WP of 1000 times of honeysuckle chlorogenic acid content was the highest(0.302%).The honeysuckle chlorogenic acid content was the highest(0.00157%)with the treatment of 10% of difenoconazole WG of 4000 times.The contents of luteolin-7-O-glucoside of honeysuckle was lower than that from other treatment 25% tebuconazole WP of 1000 times(0.00037%).It showed that the content of the loganin of Honeysuckle stem,25% tebuconazole WP of1000 times(0.106%)and 30% hexaconazole WP of 2000 times(0.104%)in the contents of loganin of honeysuckle stem was significantly higher than other treatment.The contents of loganin of disease plants CK(0.084%)was lowest.It showed that there was no significant difference in five processing the content of chlorogenic acid in honeysuckle stem.Conclusion:Through the study of control effects of the fungicide on honeysuckle branch wilt disease,and effects of the fungicide on the quality of honeysuckle,and fungicide residue,two safe and effective fungicide were screened,25% tebuconazole WP of 1000 times and 30% hexaconazole WP of 2000 times.The two fungicide should be used in rotation during the prevention and control of honeysuckle branch wilt disease in the field,each fungicide was limited to use two to three times,with an interval of 10 d,samples were taken 15 days after the last using fungicide.The fungicide dosage and freguency of use should be strictly controlled,in order to effective protection of honeysuckle. |
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