How to prevent and cure stem rot of carnation?

Stem rot is a destructive disease of carnations. The main site of the disease was on the lower branches and leaves, and the spot was round, oval and irregular, reddish brown, dark brown in severe cases, and grayish white to gray in the later stage. The diseased leaves do not fall off after they have withered, and when the disease spot on the branch surrounds the stem for a week, the upper branches and buds all die.

The pathogen of stem rot overwinters on stems and leaves and begins to occur in June next year. The disease is the most serious in midsummer and rainy season, and spreads quickly if it is planted too densely. The incidence of carnations planted in the north is very low, and fine-leaf varieties with strong disease resistance should be introduced from the north every year in the areas with serious disease in the south. During cultivation, the row spacing of plants should be increased, ropes should be pulled between rows, and flower branches should be tied and hung on the rope one by one to prevent them from crawling on the ground.

Double Bordeaux liquid can be sprayed before and at the initial stage of the disease, once every 7 days, for a total of 2 times. 1000 times of Dysen zinc should be sprayed immediately after the onset of the disease, which can prevent the expansion and spread of the disease, but cannot be eradicated.

How to prevent and cure carnation diseases

The common diseases of carnations are leaf spot, rust, gray mold, bud rot and root rot. Today, the editor shares with you the prevention and treatment of carnation diseases.

Dysen zinc can be used to control calyx rot and 5 oxidation rust prevention. In the control of other diseases, benzoate zinc, carbendazim or carbendazim were used to treat the soil before planting. When it comes to red spiders and aphids, it is usually killed with 1000 times of dimethoate emulsion.

Carnation leaf spot

Carnation is easily infected with leaf spot disease, which affects its growth and development and reduces the yield and quality of cut flowers. The pathogen of carnation leaf spot overwinters on the remains of diseased plants with hyphae and molecular spores and can survive in the soil for about a year. The disease spot is long and grayish brown, and in severe cases, the disease spot cuts off the stem, withering the upper branches and leaves. When infecting the flower, it often causes harm on the pedicel and bract. When there are many disease spots on the bract, the flower can not open or appear deformed.

Prevention and control measures:

1. Select strong and disease-free cuttings to remove the diseased body. Keep the surface of the plant dry as much as possible, and rotate crop for more than two years in places with good ventilation and good drainage. The greenhouse is well ventilated and ventilated before dusk.

two。 Leaf spot disease can occur annually, so preventive fungicides such as manganese, zinc, paracetamol and chlorothalonil must be sprayed once a week, especially after the cut flowers are harvested. 75% chlorothalonil, 50% carbendan 500 times or 1% Bordeaux solution can be used.

Virus: can not be treated, please choose seed sowing seedlings or virus-free seedlings.

Grey mold of carnation

The carnation is seriously damaged by Botrytis cinerea. After the buds, petals, stems and leaves are covered with gray mold, brown water stains appear, causing petals to rot, buds to fall off, stems and leaves to die, susceptible buds not to open, diseased flowers to lose their color, serious disease and rapid spread in high temperature and humidity, rampant damage, and must be prevented and prevented in order to protect stems and leaves, buds and petals in order to promote flowering and prolong flowering. Improve the ornamental value.

Specific control methods: spraying 1000 times potassium permanganate aqueous solution, or 1000 times sodium bicarbonate (baking soda) aqueous solution, or 25-30 times dry and pure plant ash extract once a month to wet all leaves, buds and petals evenly, it is appropriate to start dripping water, that is, it can effectively prevent the occurrence and damage of Botrytis cinerea of carnations and protect stems and leaves, buds and petals. If Rain Water is abundant, the temperature is high, the humidity is high, and gray mildew appears on the stems, leaves, buds and petals, the mixed fertilizer of 1000 times Sukeling, 1500 times Shennong chelating fertilizer and 1500 times potassium dihydrogen phosphate should be sprayed continuously for 2-3 times. or 1000 times putrel, 1000 times Zhuangfengyou, 1000 times high efficiency biological phosphorus and potassium fertilizer mixture for control, once every 7-10 days, in order to kill the pathogen and quickly restore the normal growth of the diseased site. Promote strong stems and leaves, buds and petals, promote flowering.

The above are the prevention and control methods of carnation diseases.

Prevention and treatment of leaf spot of carnation

Carnation leaf spot, also known as branch rot, stem rot. It is the world's most serious disease that harms carnations, as well as American carnation, carnation, eversummer carnation, soap grass and so on. Areas that breed carnations in Shanghai, Hangzhou, Guangzhou, Kunming and southern Jiangsu Province are also affected by the disease.

(1) symptomatic pathogens infect leaves, stems and buds. Most of the disease starts from the lower leaves, the disease spot is round, oval, irregular, with a diameter of 4mur5mm, sunken reddish brown and gradually turning grayish white. In severe cases, the disease produces a black mildew layer (conidia), and the leaves are withered and drooping, but do not fall off. Branch blight occurs when the disease spot grows on the stem and is girdled. When the bud is infected, there are round spots on the bud and a black mildew layer, and disease spots on the branches, causing the bud to die.

(2) the pathogen is semi-known subphylum Alternaria. The conidia were separated longitudinally and horizontally, and the optimum temperature for growth was 26 ℃.

(3) regular occurrence of bacteria overwintering in diseased remains with hyphae and conidia. The disease began in June of the following year, and the disease was the most serious from August to September. The spores were spread by wind, rain and irrigation water. From the wound, stomata or directly invade the plant. In the mildew and rainy season and the year with more Rain Water, the disease is easy to spread. Too dense cultivation is also prone to disease, planting in the greenhouse can cause disease all the year round, and aging leaves are also susceptible to disease. According to the observation of Shanghai Botanical Garden, Beijing fine-leaf varieties are more resistant to disease than local broad-leaf varieties. Varieties with soft grass, wide leaves and large flowers are susceptible to disease.

(4) Prevention and control methods

1. Disease-resistant and resistant varieties were selected.

2. Strengthen management, pay attention to wiping buds and pruning, remove diseased leaves, spray or apply 1% Bordeaux solution, or 50% carbendan 500 times solution, or mancozeb 500 times solution, or 75% chlorothalonil 500 times solution, spray every 1 week or 2 weeks. Keep the light transparent.

3. Avoid spraying water on the plant.

4. The effect is obvious when sprayed with 1V / L / 100 Bordeaux solution for 5 times, and 1000 times of Dysenamine has a certain effect.

5. The effect of rotation with rice is good.

6. Increase the application of phosphorus and potassium fertilizer to enhance disease resistance.