1. Phytophthora: dark brown spots appear at the base of the stem of the seedlings, slightly sunken and surrounded by whorls. In the adult stage, the disease usually develops from the lower part to the upper part. At the beginning, there will be dark green spots like water stains on the leaves, and then expand into round or irregular wheel spots.
2. Brown spot disease: the disease starts from the lower leaves and gradually spreads to the upper ones. At the beginning, it is round or oval. The color of the spots is purple brown. At the later stage, it will turn black. At the serious stage, the spots will become one by one, which will cause the leaves to wither and fall off. At last, it will cause the spots to turn black brown and then rot and die.
In the process of maintenance, there are also many pests that may be infected, such as grubs, ground tigers, aphids, etc. these pests mainly harm the stems, leaves, roots and cause certain impact on the plants.
1. Disease: first remove the diseased leaves, then pull out the diseased plants, take them outside to destroy them, and spray them with medicine. This medicine can be used for killing. Spray once every 5-7 days, at least three times in a row.
2. Insect damage: disinfect the soil before planting, and use dichlorvos, dicofol and other chemicals after finding insect damage.
