一、引言关于本病的本质,曾經有很多不同的看法。Reinking(1919)和涂治(Tu 1932)根据一般性的观察都認为本病是水害。何畏冷(1937)从病樹的腐根上分离得一种鐮刀菌,沒有經过接种試驗便認为本病乃由于該菌所致。李沛文曾經認为本病可能是由于土壤缺乏某些微量元素所致。他曾經進行初步的試驗研究1),但沒有獲得結果。澗菲尔格(1953)在广东潮汕区及廣州市郊進行了兩周一般性的观察,他認为本病的發生是由于低地土壤水位过高,或高地積水,缺乏空气,妨碍根的呼吸作用,使其窒息而死,并抑制根周围有益細菌的繁殖,間接影响礦物质的吸收,并認为柑桔上山即可解决問題“果農也就会很快把黄龍病忘掉”。曾憲朴、章文才、王家恩2)等都支持这种看法。陈其(亻暴)(1943)从1938至1941年在潮汕区作了比較广泛的調查并進行病原接种和化学藥品处理試驗。他認为本病的發生不是由于鐮刀菌的侵染或微量元素缺乏,更不是水害的 I. INTRODUCTION There have been many different opinions about the nature of this disease. Reinking (1919) and Tu Zhun (Tu 1932) according to the general observation that the disease is water damage. He Wei cold (1937) from the roots of diseased trees separated from a Fusarium, without the vaccination test that the disease is due to the bacteria. Li Peiwen once thought that the disease may be due to the lack of certain trace elements in the soil. He had conducted a preliminary experimental study 1), but did not get the result. Jianfei Erg (1953) conducted a two-week general observation in Chaoshan and Canton suburbs in Guangdong Province. He thought this disease was caused by excessively high soil water level in the lowlands, lack of air in the high ground and lack of air, impeding the respiration of the roots, Suffocating and killing them, restrain the propagation of beneficial bacteria around the root, indirectly affect the absorption of minerals, and think that if the citrus is up the mountain, the problem can be solved. “The fruit farmer will soon forget the yellow dragon’s disease.” Ceng Xian, Zhang Wencai, Wang Jiaen 2) and so on all support this view. Chen Qi (亻 storm) (1943) from 1938 to 1941 in Chaoshan area made a more extensive investigation and pathogen inoculation and chemical treatment tests. He believes that the occurrence of this disease is not due to Fusarium infection or trace element deficiency, but not water damage