| 摘要 |
Rapid, convenient and inexpensive methods for extracting fungicidal compounds from Inula are described, as well as methods for controlling fungal disease in crops by using these extracts. One preferred method of extraction starts with the dipping of leaves and stems of freshly cut Inula shoots for 10-15 seconds in organic solvent, at a ratio of 0.3-0.6 kg of shoots per 1 liter of solvent. A second method of extraction starts by shaking freshly cut Inula shoots in an organic solvent for 30 minutes at a ratio of 0.1-0.3 kg shoots per 1 liter of solvent. A third method is the same as the second, except that dried and ground Inula shoots are used a ratio of 0.05-0.25 kg dried shoots per 1 liter of solvent. For all three extraction methods, the solvent is evaporated and the residual paste (about 0.6-6.6% yield in the first method, 1.6-6.2% yield in the second method and 3.5-30% yield in the third method) is dissolved in acetone. The acetone solution is sprayed onto the foliage of potato, tomato, cucumbers, wheat and barley. The control of various fungal diseases, including downy mildews, gray mold, late blight, and powdery mildews, is demonstrated.
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