1990年冬季,我县镇龙、西兴、响滩等区乡大面积油菜叶片发紫、翻红、枯黄,经诊断,属生理性缺磷。一、典型症状心叶抽生慢,植株中上部1～2片叶的中上部叶缘变紫,中下部1～2片叶变紫红,下部1～2片叶枯黄、脱落、仅上部2～3片叶保持绿色。植株普遍矮缩,株高只有健康植株的1/2～1/3,有的油菜栽后一个多月株高仅20多厘米。二、发生原因 (一)地温低一些老冬水,死黄泥,冷沙泥油菜田由于排水不良,通气性差,导致地温低,肥效分解慢。 In the winter of 1990, large-area rape leaves of our towns such as Zhenlong, Xixing, Sitan and other areas were purple, reddish and yellowish, which were diagnosed as physiological phosphorus deficiency. First, the typical symptoms of slow heart leaf pumping, the upper leaves of the upper plant 1 to 2 leaves purple edge, the lower part of the leaves 1 to 2 purple, the lower 1 to 2 leaves yellow, fall off, only the upper 2 ~ Three leaves remain green. Plant generally dwarf, plant height of only 1/2 ~ 1/3 of healthy plants, and some rapeseed plants more than a month after the plant height of only 20 cm. Second, the causes (a) low temperature Some old winter water, dead yellow mud, cold sand mud rape field due to poor drainage, poor ventilation, resulting in low ground temperature, fertilizer decomposition slow.