The main part of stem rot is root, which gradually spreads to the stem. It is difficult to find it at the initial stage. The root will turn black and rotten when the disease occurs, but the wooden stem will remain normal, and the leaf color will remain green until death. In the late stage of the disease, the plant will die suddenly, which is difficult to save.
Solution: strengthen the maintenance, ensure the soil is wet in summer and autumn, rather wet than dry, and ensure sufficient water supply. The branches with vigorous growth shall be pruned in time, and the diseased leaves and branches shall be cleaned up; the diseased plants shall be thrown away together with basin and soil, and other plants shall be sprayed with fungicides.
When Daphne odora in Phnom Penh has leaf spot disease, there are small green dots on the leaves, and later the disease spots gradually expand and produce black spots. Generally, the onset time is from April to September. The lower leaves of the plant will first come on and gradually move upward. In serious cases, all leaves will fall off and the plant will grow weaker or even die.
Solution: water reasonably, prevent and control water stains on the leaves, increase the application of P and K fertilizer, and enhance the disease resistance ability of the plants; remove the diseased leaves in time to avoid infecting other plants. When the disease occurs, spray agent in time. You can choose mancozeb, carbendazim and tolbutine methyl once every 7-10 days.
Daphne odora in Phnom Penh will appear the phenomenon of yellow leaves, brown and dry, plant gradually yellow from top to bottom. The main time of onset is after spring temperature rising, which may occur during flowering. The bacteria invade from the roots, especially in the season of high temperature. Generally, it only takes 15-45 days from the onset to the end of the disease, and the effect is obvious.
Solution: remove the dead leaves in the flowerpot in time, and use formalin solution to irrigate and disinfect every month. In the early stage of the disease, the disinfectant should be sprayed once a week for 5-6 times in a row, with obvious effect.
At the onset of the disease, there will be spots between thick and light on the leaves, the leaves will shrink and curl, and the growth of plants will slow down, so it is difficult to form flower buds. New leaves will fall off, and in serious cases, all leaves will die. In spring and autumn, the disease is more serious.
Solution: control water and apply fertilizer, pay attention to ventilation and light transmission, promote the growth of plants, and enhance disease resistance. After the disease, the plants should be isolated in time and the contacted objects should be disinfected.
