Cotyledonary disease is a common physiological disease in the north of China. Now we will teach you how to control it.
The disease occurred on the young shoots and young leaves of rose, and it was more obvious when Rose sprouted in spring. The sprouting of diseased branches was later, the leaves were narrow and slender, hard and crisp, the edge of leaves was upward, the color of leaves was light yellow green, and the color of leaves was uneven. The new shoots are slender in apex, short in internodes, clustered in rosettes, and the growth of diseased branches is weak. This disease is mostly the whole plant.
The disease is caused by zinc deficiency, which is an essential element in the synthesis of auxin. Free and combined auxin decreased significantly in zinc deficiency, leading to growth arrest. Zinc deficiency can be easily caused by low zinc content or imbalance of other trace elements in soil. When the content of zinc in leaves is less than 10 to 15 ppm, it shows zinc deficiency symptoms.
According to the fertility of the local soil, increase the application of organic fertilizer and trace elements, improve the soil,.
② combined with the application of basic fertilizer in spring and autumn, zinc sulfate was applied. The rose garden that lack of copper or magnesium and lead to zinc deficiency should be applied with compound fertilizer containing magnesium and copper at the same time, so as to achieve obvious control effect.
(3) in early spring and autumn, spray 0.3-0.5% zinc sulfate on branches 1-2 times a year; before flowering, spray 300 mg /kg zinc naphthenate, after flowering, spray 0.2% zinc sulfate plus 0.3% urea or 300 mg /kg zinc naphthenate or 300 times zinc amino acid solution, which has obvious effect on disease reduction.
