College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471003 Henan Province, China.
University Key Laboratory of Microbiology Resources Development and Utilization, Henan University of Science and Technology, Luoyang 471023, China.
Plant Dis. 2024 Sep;108(9):2830-2837. doi: 10.1094/PDIS-01-24-0153-RE. Epub 2024 Aug 26.
Tree peony black spot (TPBS), mainly caused by , is a common leaf disease on the ornamental peony, which poses a great threat to the flower buds in the current year and the flowering quality in the next year. However, there is only one fungicide registered for the control of this disease, difenoconazole. In order to avoid the severe problem of pathogen resistance caused by long-term use of difenoconazole, it is necessary to screen more chemical fungicides for the prevention and control of TPBS. In this study, the biological activities of flutolanil, phenamacril, pyraclostrobin, and boscalid on mycelial growth, conidial germination, germ tube elongation, and sporulation quantity of . were determined, and the field control efficacy was tested to evaluate the preventive and therapeutic activities. Difenoconazole was used as a control simultaneously. The results showed that pyraclostrobin had the strongest inhibitory effects on the conidial germination, mycelium growth, germ tube elongation, and sporulation quantity, with the average EC values of 0.0517, 0.5343, 0.0008, and 0.8068 μg/ml, respectively. The inhibitory activity of flutolanil on the four developmental stages of . was weaker than that of the other three fungicides. Compared with flutolanil, boscalid, the other succinate dehydrogenase inhibitor, had more strong inhibitory effects on the mycelial growth and sporulation quantity, with the average EC values of 3.8603 and 1.4760 μg/ml, respectively. Phenamacril had a moderate inhibitory level and had more inhibitory activity on conidial germination and germ tube elongation, with the average EC values of 31.5349 and 5.2597 μg/ml, respectively. All of the four fungicides had no significant effects on the shape of spores and germ tubes. The control fungicide difenoconazole had the strongest inhibitory activity on mycelial growth, and the average EC value was only 0.3297 μg/ml. However, its inhibitory activity on the other three growth stages was not high. In the field trials, pyraclostrobin had high control efficacy on TPBS even at low concentrations, reaching a minimum of 62.6293%, which was higher than that of difenoconazole. The other three fungicides had higher control efficacy at high concentrations but decreased significantly at low concentrations. Considering the dosage and control efficacy, pyraclostrobin was the first choice for the control of TPBS. Pyraclostrobin is the preferred alternative fungicide to difenoconazole for the prevention and control of TPBS in production.
牡丹黑斑病（TPBS）主要由引起，是观赏牡丹的一种常见叶部病害，对当年花蕾和次年开花质量构成严重威胁。然而，目前仅有一种杀菌剂被登记用于防治该病害，即苯醚甲环唑。为避免长期使用苯醚甲环唑导致病原菌抗药性严重的问题，有必要筛选更多的化学杀菌剂来防治 TPBS。本研究测定了氟唑菌酰胺、苯醚甲环唑、吡唑醚菌酯和肟菌酯对的菌丝生长、孢子萌发、芽管伸长和产孢量的生物活性，并测试了田间防治效果，以评估其预防和治疗活性。同时使用苯醚甲环唑作为对照。结果表明，吡唑醚菌酯对孢子萌发、菌丝生长、芽管伸长和产孢量的抑制作用最强，平均 EC 值分别为 0.0517、0.5343、0.0008 和 0.8068μg/ml。氟唑菌酰胺对的四个发育阶段的抑制活性弱于其他三种杀菌剂。与氟唑菌酰胺相比，另一种琥珀酸脱氢酶抑制剂肟菌酯对菌丝生长和产孢量的抑制作用更强，平均 EC 值分别为 3.8603 和 1.4760μg/ml。苯醚甲环唑具有中等抑制水平，对孢子萌发和芽管伸长具有更强的抑制活性，平均 EC 值分别为 31.5349 和 5.2597μg/ml。四种杀菌剂对孢子和芽管的形态均无显著影响。对照杀菌剂苯醚甲环唑对菌丝生长的抑制活性最强，平均 EC 值仅为 0.3297μg/ml。然而，其对其他三个生长阶段的抑制活性不高。在田间试验中，吡唑醚菌酯即使在低浓度下对 TPBS 也具有较高的防治效果，最低防治效果达 62.6293%，高于苯醚甲环唑。其他三种杀菌剂在高浓度下具有较高的防治效果，但在低浓度下显著下降。考虑到剂量和防治效果，吡唑醚菌酯是防治 TPBS 的首选药剂。吡唑醚菌酯是苯醚甲环唑的首选替代杀菌剂，可用于生产中防治 TPBS。
