四、要素的缺乏症和过剩症 (一)缺氮症 叶片绿色减退成为淡黄色,新芽细小难以伸展,纤维增加,易老化,若症状加深,生育就停止。并因叶的含氮量减少,不仅生育不良,而且制出的茶叶品质也显著变劣。 (二)缺磷症 根呈红褐色,伸展不良。老叶细小,呈暗绿色、光滑无皱纹。新叶黄白化,生育停止。 Fourth, the elements of deficiency and excess disease (A) of the nitrogen deficiency leaves green reduced to pale yellow, small sprout difficult to stretch, fiber increase, easy to aging, if the symptoms deepen, childbearing stopped. And because of the reduced nitrogen content of leaves, not only malnutrition, but also the quality of tea made significantly worse. (B) phosphorus deficiency root was reddish brown, poor extension. Small old leaves, dark green, smooth and wrinkle free. New yellow leaves, birth stop.