胡麻炭腐病之研究

Study on the charcoal rot disease of Sesame

吳雅芳(Wu, Y. F.) ； 林國詞(G. C. Lin) ； 吳盈慧(Y. H. Wu) ； 鄭安秀(A. H. Chen)

《臺南區農業改良場研究彙報》 71期 (2018/06) Pp. 70-83

摘要

胡麻炭腐病是由Macrophomina phaseolina感染所引起，在田間常造成嚴重的損失。病原菌的菌絲在30 ～ 35℃生長快速，藥劑篩選結果以三得芬、免得爛、四氯異苯腈對病原菌菌絲生長抑制率較高，種子帶菌檢測結果發現半數以上的樣品均帶有炭腐病的病原菌，推測此為臺灣田間炭腐病的重要感染來源。綜合田間觀察及各項試驗結果，並以臺灣目前胡麻的耕作模式進行分析，胡麻炭腐病在臺灣的病害環以種子帶菌及苗期發病株為重要的感染源，以藥劑或木黴菌處理種子，可有效抑制苗期的發病並降低田間感染源，在中耕後再輔以1至2次的預防性防治，可有效降低此病害的發生。現有技術：農民常過量施用農藥防治胡麻炭腐病卻可能因時機及藥劑種類不對而達不到防治效果。創新內容：以種子處理降低感染源並配合適時的田間防治，可有效降低炭腐病的發生率。對產業影響：透過正確的防治措施，可減少農藥的施用量，減輕因病害所造成的損失。

關鍵字

胡麻 ； 炭腐病 ； 萎凋 ； 防治 ； 種子處理

並列摘要

Sesame charcoal rot disease is caused by Macrophomina phaseolina, frequently leading significant yield losses in field. The mycelia of the pathogen grew rapidly at 30-35°C. The results of chemicals screening showed that Tridemorph, Metiram and Chlorothalonil had high inhibition rate on mycelium growth. More than half of the seed samples were detected carrying Macrophomina phaseolina. Seed carrying this pathogen is supposed to be the important source of infection in the field. Comprehensive observation of the field situation, experiments conducted in this study, and analysis of the current farming mode of sesame in Taiwan suggested that inoculums of this disease are largely from seeds and disease seedlings. The disease severity in seedling-stage could be effectively inhibited by seeds treated with chemicals or Trichoderma fungus as biocontrol agent to reduce the inoculums source. Additionally 1-2 times of preventive control as supplement can effectively reduce the disease severity of charcoal rot disease of sesame. What is already known on this subject? Fungicides applied by farmers to control charcoal rot may not be effective due to the incorrect application timing or fungicides. What are the new findings? A prevention and control strategy was formulated to prevent and control charcoal rot by seed treatment in combination with appropriate chemical application in field. What is the expected impact on this field? Through proper prevention and control measures, the amount of fungicides can be reduced and the losses caused by this disease can also be reduced.

並列關鍵字

Sesame ； charcoal rot disease ； wilt ； control ； seed treatment