Prevention and control of diseases and pests of Polygonatum polygonatum

Disease

Black spot is the main disease of yellow essence, and the pathogen is a kind of half-known fungus in fungi, which harms the leaves. At the initial stage of the disease, irregular yellow-brown spots appear from the leaf tip, and there is a purplish-red edge at the junction of the healthy part; later, the disease spot spreads downward, and the rainy season is more serious. The leaves of the diseased part are withered and yellow. Prevention and control methods: clear the garden during harvest and eliminate the disease and residues; spray 1 ∶ 1 ∶ 100 times Bordeaux or 50% acetaminophen 1000 times before and at the initial stage of the disease, once every 7-10 days, several times in a row.

Leaf spot symptoms: the main harm to the leaves, the initial onset of the disease from the base, the leaf surface appears discoloration spots, after the disease spot expansion is oval or irregular shape, the size of 1cm2 or so, the middle light white, the edge of brown, near the healthy tissue has obvious yellow halo, the disease spot shaped like an eye. When the disease is serious, many disease spots heal and cause the leaves to die, which can gradually spread upward and finally the leaves of the whole plant die and fall off. The pathogen of the disease belongs to semi-knowing subphylum. Characteristics of the disease: the disease generally appeared on the leaves of the undead plants in early June, then transferred to the basal leaves of the new plants germinated in the same year at the beginning of July, and gradually moved up, and the disease was more serious by the end of July. The whole plant withered. In August and September, the disease reached the peak with the death of plants in the field caused by many other causes. Sporadic disease spots appeared on the diseased plants in October and were common and serious in the first ten days of November. Prevention and control is like the prevention and control of black spot.

Anthrax symptoms: the main harm to leaves, fruit can also be infected. After being susceptible to the disease, the disease spot first appeared at the leaf tip and leaf edge. At first, it is a small reddish brown spot, and then expands into an oval or semicircular, dark brown, slightly sunken in the middle of the disease spot, often perforated and shedding, the edge is slightly raised reddish brown, there are yellow halo circles on the periphery, and small black spots are scattered on the disease spot under wet conditions. The pathogens are semi-known subphylum, Coelospora, Coleoptera, Coleoptera, Alternaria. The characteristics of occurrence: it started in late April and was the most serious from August to September. There is a trend of aggravation year by year. Control methods: carbendazim or the same black spot control method

Symptoms of root rot: the disease mainly infects the root, Fusarium, is a half-known fungus, the root produces watery brown necrotic spots at the initial stage of the disease, and in severe cases, the whole root decays, only fibrous vascular bundles remain, and the diseased part is brown or reddish brown. When the humidity is high, the white mildew layer (conidia) is produced on the surface of the rhizome. Diseased plants are easily uprooted from the soil because of root rot. With the development of the disease, the aboveground parts grew badly, the leaves turned yellow gradually from outside to inside, and finally the whole plant withered. Prevention and treatment methods: copper preparation or carbendazim or carbendazim can be used for soil disinfection.

Symptoms of stem rot: the damaged plants gradually spread upward from the lower leaves, Fusarium, belonging to half-known bacteria, showing symptoms of green wilt (that is, bluish gray, like scalded by boiling water), and finally the whole plant showed symptoms, which was easy to distinguish from healthy plants. Some diseased plants have acute symptoms and there is no obvious process of gradual development from bottom to top, which is more common after rain. It usually takes about a week to show the disease from the first diseased leaf to the whole plant, the short one only takes 1-3 days, and the long one lasts more than 15 days. The base of the stem of the diseased plant is soft, and the inner part is loose (can be identified by hand pinch). It is easy to turn back in case of wind. The root system of the plant is obviously underdeveloped, the root is few and short, blackened and rotten. Stem dissection examination showed that the pulp was empty, and red disease could be seen in the root, stem base and pith. Control method: same root rot.

Insect pest

Grub: a member of the family Coleoptera. Damage to the larvae, bite off the seedlings or eat the roots of the seedlings, resulting in broken seedlings or root cavity, the harm is serious. Kill tigers with the same drugs or with pesticides with conventional low-toxic pesticides.

Ground tiger: harms seedlings and rhizomes. Control methods: 75% phoxim EC can be used to mix seeds according to 0.1% seed quantity; during the field occurrence period, 90% trichlorfon is irrigated with 1000 times liquid; adults are trapped and killed with black light or poison bait; manure should be fully mature, preferably compost at high temperature.