Cultivation of Cornus officinalis and control techniques of anthracnose

Cornus officinalis alias jujube skin, dogwood flesh, for dogwood family plants, to remove the seeds of the pulp used as medicine, there are tonic liver and kidney, astringent antiperspirant function, is one of the main economic crops in Huoshan County.

I. Cultivation techniques

1. Characteristics and growth habits. Dogwood for deciduous trees or shrubs, 2-10 meters high, alternate, leaves elliptic, apex acuminate, base wedge, umbels axillary, flowering before leaves, flowers yellow. Drupe long elliptic, red when mature, flowering 2-3 months, fruiting 4-10 months. Dogwood is generally distributed in low hills and gentle slopes with thick humus limestone soil at an altitude of 250-800 meters. There are few wild dogwood in barren land. Love warm and humid climate. Frost damage at flowering stage will seriously reduce production.

2. Land selection and preparation. Choose a sandy loam with good drainage and deep soil layers. The idle land beside the ditch in front of and behind the house can also be planted. Organic fertilizer 4000-5000 kg shall be applied every 667 square meters, and deep ploughing shall be carefully leveled.

3. Breeding methods

(1) Seed breeding. selecting fruits with large fruit shape, full seeds and no diseases and insect pests, stripping the flesh, soaking in human urine for 15-20 days, digging a deep hole in the sunny place in November, applying enough organic fertilizer at the bottom of the hole, spreading seeds, covering with pig dung or miscellaneous fertilizer for 15-20 cm, digging and inspecting at the beginning of April of the next year, and taking out and sowing seedlings when the embryos of each seed have germinated and cracked. Nursery land should be selected wet, fertile, loose soil, deep ploughing, clean weeds, apply sufficient base fertilizer, rake flat bed, bed width 1.4-1.7 meters, in the bed open 20 cm deep, row spacing 3 - 5 cm, width 25 cm drill ditch, ditch re-apply base fertilizer, every 667 square meters apply 1500-2000 kg, seed on the base fertilizer, seed spacing 3-5 cm, after sowing with fire ash cover and cover fine soil flush with the bed surface. After sowing, prevent people and animals from trampling, and the seedlings can emerge in the same year. If the seed without basal fertilizer germination treatment is directly planted in the seedling field, it will not emerge in the first year, and it will not emerge until April of the second year, and the seedlings are not neat. After emergence, intertill and weed in time, and apply fertilizer appropriately. When the seedlings are about 1 meter high, they can be transplanted.

(2) Cutting seedlings. Select strong, disease-free, fruitful mother plants, cut branches about 66 cm long in February to March, soak them in 1:20000 sodium acetate solution for one day and night, insert them into the soil according to the row spacing of 33 cm and the plant spacing of 10-13 cm, and the branches are about 13 cm in the soil. The seedbed should be applied with sufficient base fertilizer to keep moist. If conditions permit, it can be covered with small arch shed to keep moist and warm. Transplant after the branches grow fibrous roots and survive.

(3) Colonization. The transplanting time of seed seedling and cuttage seedling were both winter and spring, and the survival rate was higher in winter. Choose sunny, fertile, deep soil planting. The depth of the hole depends on the length of the taproot. When planting, the roots of seedlings should be comfortable, do not bend, do not hurt the roots, each plant is 2.7-3 meters apart, generally 60 trees are planted in 667 square meters of mountain area, covered with soil after planting, and poured with appropriate amount of water and water manure.

4. Field management. The field management of dogwood must achieve "four diligence and one prevention," that is, frequent weed removal, frequent soil cultivation, frequent pruning, frequent fertilization, pest control. It can be done in stages.

(1) Seedling management. Always keep the soil moist before emergence to prevent dry hardening and cover it with grass. Water in dry season. After the seedlings are unearthed, remove the cover grass and pull out the grass frequently. The seedling height is about 15 cm, and thin manure is applied once to accelerate the seedling growth. If the seedlings are too dense, thin the seedlings when they are 12 cm high. When the seedlings cannot reach the planting height in the same year, they are covered with weeds and pig dung before winter to facilitate heat preservation and moisture retention, so that the seedlings can safely overwinter.

(2) Post-planting management. After planting, intertill and weed 4-5 times a year to keep weeds free around the plant. When transplanting, such as base fertilizer foot, that year can not topdressing, after the spring and autumn two seasons topdressing once a year. Fertilization amount according to the age of the tree, small trees less fertilizer, trees more fertilizer, more than 10 years old trees per plant can be applied human and animal manure 10-15 kg. The method is to ditch all around the tree, water after fertilizer is applied, and cover the ditch with water. The first year after planting and into the fruiting period should pay attention to watering, flowering or summer drought, will cause flower and fruit drop. After planting the second year in early February before the top branches will be cut off, promote lateral growth, young trees in early spring every year will be tree base cluster branches cut off, promote trunk growth. Attention should be paid to the trimming of the crown and the thinning of the lower branches, so that the branches of the crown are evenly distributed, so as to facilitate ventilation and light transmission and improve the fruit yield. Young trees should be cultivated 1-2 times a year, adult trees can be cultivated 1 time in 2-3 years, if found that the roots exposed to the surface, should be timely use soil to block the roots.

II. Prevention and control of dogwood anthracnose. Cornus anthracnose is also called black fruit disease, the diseased fruit rate can reach more than 50%, and the tree vigor decreases, the fruit in the second year decreases, affecting the yield and quality.

1. Symptoms. Young fruit disease, bacteria mostly from the top of the invasion, downward extension of disease spots, disease black, reddish-brown edge, disease spots gradually extended to the whole fruit, and black dry shrink, more not falling off. Results The disease initially appeared as brownish red spots, then expanded into round or oval black concave spots, the edge of the disease spots was reddish brown, and there were red halo rings around the periphery. Under wet conditions, the disease parts produced small black spots and orange spore masses. The spots unite, blackening the whole fruit, drying out and shedding.

2. Pathogenesis. The pathogen overwinters on the diseased fruit in hyphae and conidia, and produces conidia in the middle and late April of the next year. Conidiospores are produced during the growth period and spread by wind and rain to expand the damage. The peak period of fruit anthracnose was from July to September. In the years with large amount of overwintering bacteria, more rain and high humidity, the disease occurred early and seriously; in the old years, the disease occurred seriously due to weak growth, and the disease occurred lightly due to vigorous growth; the disease occurred heavily due to extensive management, and the disease occurred lightly due to pruning and fertilization.

3. Prevention and control methods

(1) Agricultural control. After autumn fruit harvest, cut off diseased branches of diseased fruit, bury diseased fruit on the ground, reduce overwintering bacteria source; strengthen field management, prune, water and fertilize, promote strong growth and enhance disease resistance.

(2) Chemical control. At the early stage of disease, timely spray 25% Shibaoke emulsifiable solution 1000 times, or 50% Shibaoke wettable powder 1000-2000 times solution for prevention and control.