珠兰是一种经济价值很高的香料作物,不仅从中可提取芳香油,更重要的是可用它制作花茶。但长期以来珠兰在生产上受到被群众称为“落叶鬼”的珠兰叶线虫为害,发病后造成珠兰叶的大量脱落,降低珠兰花的产量和质量。该线虫病由于以往研究甚少,防治上亦无有效措施,所以花农在发病重时,只得连盆倒去。据不完全统计,从八三年到八六年 Zinnie is a high-value spice crop, which not only extracts aromatic oils, but more importantly, it can be used to make scented tea. For a long time, however, it has been attacked by the perennial Nelumbo nucifera, which is known by the masses as a “deciduous ghost.” After the onset of the disease, a large amount of pearl oily leaves are shed and the yield and quality of the orchid are reduced. The nematode disease has little research on the past and no effective measures on prevention and treatment. According to incomplete statistics, from 1983 to 1986