栀子黄化病或叫缺绿症 ,为生理性病害。患病后 ,枝梢顶端幼嫩叶片颜色褪绿 ,叶肉变为淡黄色 ,叶脉仍为绿色 ,最后发展全叶黄白色。如不及时防治 ,1～ 2年就会全株枯死。　　其致病的主要原因 :( 1 )土中石灰过量 ,造成根尖死亡 ;( 2 )土中铁元素缺乏或不能被吸收 ,影响叶绿素的 Gardenia yellow disease or lack of green disease, physiological diseases. After the illness, shoot tip young leaves chlorotic green leaves, leaves become pale yellow, veins are still green, and finally the development of the whole leaf yellow-white. If not timely control, 1 to 2 years will die. The main causes of its disease: (1) excessive lime soil, causing apical death; (2) soil iron deficiency or can not be absorbed, affecting chlorophyll