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Sensitivity of Exserohilum turcicum to Carbendazim and the Fungicide’s Efficacy in Controlling Northern Corn Leaf Blight in Thailand |
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| รหัสดีโอไอ | |
| Creator | Thanada Nakngoen |
| Title | Sensitivity of Exserohilum turcicum to Carbendazim and the Fungicide’s Efficacy in Controlling Northern Corn Leaf Blight in Thailand |
| Contributor | Kittithud Trachu, Supharoek Limdolthamand, Veeranee Tongsri, Tida Dethoup, Pattavipha Songkumarn |
| Publisher | Department of Agriculture |
| Publication Year | 2568 |
| Journal Title | Thai Agricultural Research Journal |
| Journal Vol. | 43 |
| Journal No. | 3 |
| Page no. | 252-264 |
| Keyword | northern corn leaf blight, Exserohilum turcicum, carbendazim, fungicide sensitivity |
| URL Website | tci-thaijo.org/index.php/thaiagriculturalresearch |
| Website title | Thai Agricultural Research Journal |
| ISSN | 3027-7272 |
| Abstract | Northern corn leaf blight is caused by Exserohilum turcicum. The use of carbendazim in combination with demethylation inhibitor fungicides is included in the recommendations for controlling this disease in Thailand. However, the efficacy of carbendazim against E. turcicum remains unclear. This research assessed the sensitivity of E. turcicum isolates (n = 36), collected during 2021–2022, to carbendazim along with sequence analysis of the beta2-tubulin (Tub2) gene at codons 167, 198, and 200 of the E. turcicum isolates with the highest and lowest sensitivity to carbendazim (n = 2/group). Field efficacy of carbendazim and other fungicides for controlling E. turcicum in sweet corn was also determined. The results revealed that approximately half of the E. turcicum isolates exhibited EC50 values exceeding the established baseline sensitivity (1.23–8.70 beta g/mL). The frequency distribution of EC50 values showed a unimodal distribution with positive skewness, indicating a shift towards reduced sensitivity in the population. Sequence analysis of the Tub2 gene revealed no differences between the isolates with the highest and lowest sensitivity to carbendazim. Field trials with natural infection revealed that carbendazim (50% SC) was less effective at disease suppression compared to tebuconazole+trifloxystrobin (50+25% WG) and azoxystrobin+difenoconazole (20+12.5% SC), applied at recommended rates. These findings suggest a decline in sensitivity to carbendazim within the E. turcicum population in Thailand. The control efficacy of carbendazim on E. turcicum was relatively low compared to the other recommended chemical mixtures. |
