Control techniques of Diseases and insect pests in Cornus officinalis

Cornus officinalis is a kind of medicinal material liked by medical institutes of all ages. It has been introduced and cultivated in Sichuan. The diseases endangering Cornus officinalis mainly include anthracnose, angular spot disease, gray plaster disease, etc. The pests endangering Cornus officinalis mainly include green tail silkworm moth, big lionfish moth, Cornus fruit moth, yellow thorn moth, wood looper, green leg belly locust, Isatis indigotica, small green leafhopper, spotted wax cicada, etc. Let's take a look together!

anthracnose

[Hazard characteristics] Anthracnose is also known as black spot disease, black fruit disease, black scar dysentery. Young fruit disease (fruit anthracnose), mostly from the top of the invasion, disease spots from the top of the fruit downward expansion, disease part black, reddish-brown edge, disease spots gradually extended to the whole fruit, fruit black dry shrinkage, mostly do not fall off. The disease was brown spots at the beginning, and gradually expanded into round or oval black depressed spots with reddish brown edges and red halo circles around the periphery. The pathogen infects the leaves (leaf anthracnose), initially reddish brown spots, later expanded into brown round spots, about 1~4 mm in diameter, the edge of the spots reddish brown, the periphery has faded halo, the spots often perforated and shed. The peak period of fruit anthracnose was from June to August, and leaf anthracnose was from May to June.

[Control method] Select sandy loam with deep soil layer and good drainage for cultivation, not too dense, strengthen management, apply less nitrogen fertilizer and more phosphorus and potassium fertilizer during disease period, promote plant health, improve plant disease resistance and reduce harm. Remove fallen leaves, dead fruit buried deep or burned, reduce the source of infection. 1∶2∶200 Bordeaux mixture was sprayed at the beginning of the disease.

angular leaf spot

[Harm characteristics] Angular spot mainly damages leaves and fruits. Leaf disease, early leaves appear dark purple small spots, the edge of the spot is not obvious, only epidermal cell color, leaf back asymptomatic, fruit disease, rust brown round spots, diameter of about 1 mm, the number of spots, connected into pieces, so that the top of the fruit into rust brown, only damage the pericarp, the spot does not go deep into the flesh. From May to the end of October, July is the peak of the disease.

[Control method] Strengthen seedling management, interplant leguminous plants, strengthen plants and reduce damage, remove diseased leaves, ventilate and transmit light, reduce infection sources, increase phosphorus and potassium fertilizer and farm manure, improve plant disease resistance, spray 1:2:200 Bordeaux solution protective agent on tree crown in May, once every 10~15 days for 3 consecutive times, or spray 50% wettable anti-bacteria solution 800~1000 times.

gray plaster disease

[Hazard characteristics] Gray plaster disease generally occurs on the trunk or branch of an old tree more than 20 years old. The disease patch forms an irregular thick film on the branch, like plaster, so it is called plaster disease. Where the soil is poor, poor drainage, soil moisture, poor ventilation and light transmission, plant growth is weak when the disease is serious.

[Prevention and control methods] Strengthen conservation and management, adjust forest density, remove weak and strong trees, remove small and keep large trees, adjust lighting conditions, improve plant disease resistance, prune diseased old plants reasonably, remove diseased old branches, renew plants, retain growing branches from bore, gradually replace seriously ill branches, reduce pathogen sources, scrape hypha membrane with knife, apply Baume 5 degree stone sulfur mixture or lime milk to diseased parts, Dichlorvos emulsifiable solution 1000 times was sprayed on the tree crown of scale insects during the occurrence period of associated pathogens, and bordeaux mixture 1∶1∶100 was sprayed for protection at the initial stage of disease, once every 10~14 days, for several consecutive times.

Phaerocera viridis

[Hazard characteristics] Green tail silkworm moth also known as water green moth, swallowtail moth, big green insect. Larvae feed on leaves, resulting in translucent spots, holes and notches. In severe cases, they can eat up the whole leaves. Older larvae can also eat petioles, which has a great impact on the normal growth of dogwood medicinal trees and the yield and quality of medicinal materials. It usually occurs from mid-May to early October.

[Control method] Cornel medicinal tree should avoid mixed cultivation with other forest medicinal materials such as maple poplar, elm, walnut or Euonymus bark, peony, peony, etc., so as to facilitate management and control. In the adult occurrence period, use black light lamp to trap and kill, spray 90% crystal trichlorfon 800 times solution in the early stage of disease, and manually pick eggs in the peak spawning period or artificially capture larvae in the peak period.

Phioconia macrocephala

[Harm characteristics] Big moth also known as big bag moth, skin worm, debt avoidance moth, bag worm, bag worm. Larvae feed mainly on leaves, but also on shoots and young fruits. When eating leaves, it can bite into holes, notches, and even eat up the leaves with only branches left, seriously affecting the flowering and growth of medicinal materials. In August and September, larvae enter the stage of old age and gluttony, which is seriously harmful.

[Control method] Manually remove the insect sac, spray 90% crystal trichlorfon 800~1000 times at the peak stage of larvae, pay attention to protect various parasitic and predatory natural enemies birds, parasitic wasps, parasitic flies, etc. at the larva stage and pupal stage.

Cornel fruit moth

[Hazard characteristics] Cornus fruit moth also known as stone jujube worm, cornus flesh worm, jujube worm. The larvae bore the flesh into vertical and horizontal worm channels in the fruit, and the empty fruit was filled with worm dung, which aggravated the damage with the maturity of the fruit. From late September to early October, fruit ripeness is the peak period of damage.

[Control method] Remove early fruit drop in time. When the fruit is mature, harvest it in time to reduce the number of overwintering insects. Treat the soil around the trunk with 2.5% trichlorfon powder, which can kill pupae and larvae.

yellow thorn moth

[Hazard characteristics] Yellow thorn moth is also known as foreign chili, hairy chili insect. After 4 instars, larvae can eat whole leaves, leaving only main veins and petioles, seriously affecting the growth and development of host plants and the yield of medicinal materials, even causing host death. It is often damaged from late June to late September.

[Control method] Combined with winter pruning or manual elimination of overwintering insect cocoons, black light lamp is used to trap adults. When the first instar larvae cluster on the back of leaves, they can be manually removed. In the early stage of disease, 90% crystal trichlorfon 800~1000 times solution can be sprayed.

wood looper

Wood inchworm is also known as measuring insects, bridge-making insects, hanging worms and so on. Larvae feed on leaves, causing bare branches, weak tree vigor, severely damaged that year can not bear fruit, fruit has also fallen due to malnutrition. The damage period of larvae (from early July to early October) lasts about 3 months.

Control method: After spring, dig soil around the trunk to kill pupae, spray 90% trichlorfon 800 times solution at the early stage of larvae, spray 2.5% deltamethrin 2500~5000 times solution at adult stage.

Phaedra viridis

[Hazard characteristics] Green-legged belly locust, also known as grasshopper. Harm dogwood leaves, often bite into holes or notches, serious, its leaves eat up, leaving only veins, affecting growth and fruit maturity. June to July is the most prosperous.

[Control method] From autumn to early April of the next year, combined with manure shoveling and composting to kill eggs, 1~2-year-old young locusts are killed manually when they are concentrated, and 90% crystal trichlorfon 800 times solution is sprayed in the morning when there is dew.

Green leafhopper

[Hazard characteristics] Green leaf cicada is divided into Isatis leaf cicada and small green leaf cicada. Isatis leaf cicada is also known as Isatis leaf jumping cicada, also known as small green leaf jumping cicada and small green dust seed. Adults and larvae mainly damage leaves. July, August and September are the serious harm periods.

[Control method] Use black light lamp to trap adults, remove weeds in and around the medicinal herb garden, reduce the base number of overwintering insects, and spray dichlorvos emulsifiable solution 1000 times at the early stage of disease.

Calycephala maculata

[Hazard characteristics] Spot coat wax cicada also known as red lady, spot coat, Chinese toon skin wax cicada, Ailanthus chicken. Adults and larvae can prick and suck sap from young branches or leaves. White or yellow spots appear on the surface of the stem and leaf of the victim, gradually turning into black-brown polygonal dead spots. The damage usually begins in April or May.

[Control method] In winter, scrape or kill the overwintering egg mass on the branches and stems with wood hammer, and spray 1500 times solution of dichlorvos emulsion at the initial stage of disease.