Pesticide control and non-pesticide control measures of potted orchid anthracnose

Friends who cultivate orchids all know that anthracnose is a common disease of orchids. Although it does not cause orchids to be "wiped out", it is so lingering that it is difficult to cure it. Let's take a look at the comprehensive prevention and control measures of potted orchid anthracnose.

I. Prevention and control of anthracnose with pesticides

The most commonly used method for the prevention and control of anthrax is the use of pesticides. Pathogens can quickly eliminate the threat of diseases, so that chemical control can kill or inhibit a large number of pathogens in a short time, and quickly eliminate the threat of diseases. Attention should be paid to the following three points when using pesticides for prevention and control:

The main results are as follows: (1) the preventive and therapeutic drugs should be selected. We should pay attention to the prevention and treatment of anthrax. The selection of drugs for prevention and treatment should be targeted. Generally speaking, some broad-spectrum fungicides, such as copper hydroxide, thiophanate methyl, carbendazim, etc., should be used as preventive drugs, while during the onset period, it is appropriate to choose some agents for the treatment of anthrax, such as Shibaogong (prochloraz manganese salt), Kailun (pyrazolyl carbendazim), Shigao (phenylether methoconazole) and so on. Preventive and therapeutic drugs should be selected separately, and should not be used in the same way.

(2) Prevention and control in winter is indispensable. The pathogen of orchid anthracnose overwinters with hyphae in diseased leaves or soil, so it is essential to spray and irrigate anthracnose control drugs in winter, which is very important to eliminate latent hyphae. In the process of prevention and control of anthracnose, when diseased plants are found, the damaged parts should be cut off and burned in time.

(3) avoid using the same drug repeatedly for a long time. When the same drug is used repeatedly for a long time, the pathogen is easy to produce drug resistance and has no control effect. No matter it is prevention or treatment, several kinds of drugs should be used alternately, and it is not suitable to use the same drug repeatedly for a long time. However, it is not suitable to change dressing frequently. Each drug must be used three times in a row and then change to another drug.

II. Non-pesticide control of anthrax

Spraying chemical pesticides can prevent and control anthrax to a certain extent, but it often causes environmental pollution. Using non-pesticides to control orchid anthracnose can not only overcome the disadvantages of pesticide pollution, but also benefit the growth and development of orchids. Here are some folk prescriptions for non-pesticide control of anthracnose.

(1) quicklime aqueous solution. First, the quicklime was weathered into powder with an appropriate amount of water, and the ratio of weathered quicklime powder Qingshuimei 1: 60 was put into a container to soak, and its clarification solution was sprayed with orchid plants and orchid farm environment to control anthracnose. Quicklime is alkaline and can also prevent and cure white silk disease.

(2) leek juice. The anthracnose can be treated by mixing leek juice and clear water at the ratio of 1:60 and spraying orchid plants twice a day for several days.

(3) pig bile. Anthracnose and soft rot can be controlled by mixing pig bile and clear water at the ratio of 1 to 100, adding a small amount of washing powder and spraying orchid plant.

(4) vinegar. Spraying vinegar on the leaves of orchids can prevent anthracnose. Take a tablespoon of vinegar, pour it into 1 kilogram of water and spray the orchid plant. Vinegar can also be added when using pesticides.

The above are the pesticide and non-pesticide control measures of orchid anthracnose, in order to control the pathogen to produce drug resistance, can be used pesticide control and non-pesticide control of paspalum to prove that the effect is good, you can refer to.

Identification and control skills of orchid anthracnose

Anthracnose occurs in all areas where orchids are cultivated in China, especially in Tianjin, Shanghai, Nanjing, Guangzhou, Chengdu, Lianyungang and Xi'an. When the disease is serious, it not only affects the normal growth of orchids, but also leads to the death of whole leaves. Anthracnose not only harms Cymbidium, Jian Orchid, Cold Orchid and other orchids, but also harms epiphytic orchids such as tiger orchids and broad-leaf orchids, as well as Guangdong evergreen, violets, marigolds, mulberry, sweet-scented osmanthus and other flowers.

First, symptom characteristics. Anthracnose mainly harms the leaves of orchids and sometimes infects stems and fruits. The disease spot on the leaf begins to be round or oval, the center is light brown or grayish white, the edge is dark brown or dark brown, and there is a greenish halo around it; black spots are produced on the disease spot in the later stage, scattered or slightly arranged in a wheel, and orange-yellow sticky matter will appear under wet conditions. With the development of the disease, the disease spot on the leaf can expand into irregular spots up to several centimeters long, or the disease spot can be connected into a piece, and finally cause the leaves to wither and yellow. The size of the disease spot on the leaf is 3-20 mm, which varies greatly. Irregular or striped black-brown spots appeared when the stems and fruits were damaged.

Second, the law of the disease. The disease is caused by several kinds of anthrax in fungi. The pathogen overwinters on diseased leaves, diseased leaf residues and withered leaf bracts, and spreads by wind, rain and insects under suitable climatic conditions the following year; invades the plant mainly through various wounds. The disease can occur almost all the year round, but it is serious in summer and autumn. Such as the southern plum rain season, or autumn typhoon accompanied by heavy rain, so that orchid leaves injured, or high humidity and muggy heat, placed too dense, poor ventilation, stagnant water in the basin, the disease is the most serious. Watering from above the plant is easy to spread the disease. Because the roots of orchids cultivated in that year are easy to be damaged, the disease is often serious. The heavy consolidation of basin soil will also aggravate the disease.

III. Prevention and control methods

1. Strengthen cultivation management: greenhouse should be ventilated and transparent. In winter and early spring of the following year, special attention should be paid to keeping warm so that it will not suffer frost and frost damage, so as to enhance its ability to resist diseases. After moving outside, it should be placed in the shade shed to prevent the attack of wind and rain, at the same time, there should be enough sunlight in the shed, and it is better to pour it slowly from the edge of the flowerpot or soak in the basin to irrigate, so as to reduce the spread of bacteria with water droplets caused by pouring above. Flowerpots should not be placed too tight. Orchid fertilization should pay attention to science. As we all know, orchids should be ripe rather than grown. Anthrax can easily be induced by the application of raw fertilizer. When potted, new soil should be replaced.

2. remove the source of infection: remove the diseased leaves and their remains in time, especially before entering the house in winter, burn or bury the diseased leaves on the plant and the remains in the basin thoroughly, so as to eliminate the source of infection and prevent the spread of the disease. In winter and spring, 0.5-1% Bordeaux solution was sprayed on the ground, basin and plant for 1-2 times.

3, chemical control: before the onset of the disease, 0.5-1% Bordeaux solution or 65% Dyson zinc wettable powder 600-800 times, sprayed every 7-10 days, has a better protective effect. During the onset of the disease, 50% carbendazim 800x solution or 75% methyl topiramate 1000-fold solution can control the spread of the disease.

4. Non-pesticide prevention and treatment: ⑴ vinegar. Spraying vinegar on the leaves of orchids can prevent anthracnose. Pour 1 tablespoon of vinegar into 1 kg of water and spray the orchid plant. Vinegar can also be added when using pesticides. ⑵ leek juice. The anthracnose can be treated by mixing leek juice and clear water at the ratio of 1:60 and spraying orchid plants twice a day for several days. ⑶ pig bitter bile. Anthracnose and soft rot can be controlled by mixing pig bitter bile and clear water at the ratio of 1 to 100, adding a small amount of washing powder and spraying orchid plant. ⑷ quicklime aqueous solution. First, the quicklime was weathered into powder with appropriate amount of water, then the weathered quicklime powder and clear water were put into the container at the proportion of 1:60, and the clarification solution was sprayed around the orchid plant to control anthracnose. Quicklime is alkaline and can also prevent and cure white silk disease of orchids.

Responsible editor: Molika tropical orchid pest control methods: disease and pest management: orchid diseases are mainly caused by excessive watering, poor drainage, lack of ventilation, and some are external infections. Anthracnose: yellow-brown sunken spots appear in the initial stage of the damaged leaves, forming brown spots outward. Prevention and treatment: remove diseased leaves and ventilate the orchid shed; spray with 50% carbendazim or 50% topiramate 500-600 times at the initial stage of the disease. Spot rot: for many orchids, this is an extremely serious disease that starts at the base of the stem and quickly spreads to the leaves and roots. Bacterial soft rot: a devastating disease that is highly contagious and begins with water-soaked dark green spots at the end of the leaves and then spreads. Bacteria invade from the wound, easy to infect orchids are Cartland, Phalaenopsis, tiger orchid and so on. Prevention and control methods: first of all, do a good job in the environmental hygiene of the orchid nursery, clean up the dead branches and leaves in time, eliminate and eliminate the source of bacteria; when diseased plants are found, immediately cut off and burn them, spray 50% Dysenamine 800-1000 times every 7 days, 70% methyl thiophanate 700-800 times, 50% wettable carbendazim 1000 times, alternate use. Rot: caused by rot mold, generally harmful to seedlings, sprayed with Actinium Sulfate or other fungicides. Black spot: black spots appear on the leaf surface, which gradually expand, so that more than half of the leaves are withered and blackened, generally due to excessive watering and poor ventilation, it is necessary to improve ventilation and drainage conditions and spray with fungicides. When cutting off diseased leaves, the knife needs to be disinfected. Virus disease: the disease is quite common in orchids, so far no effective control methods have been found, but it is very effective to take comprehensive preventive measures to control it. Prevention and treatment methods: strictly select and plant virus-free tissue culture seedlings and sowing seedlings; timely eliminate weeds in the greenhouse to control diseases; immediately remove and burn diseased plants; contact with diseased plants, tools and hands should be disinfected in time, pots and potted materials planted with diseased plants can no longer be used. Scale insect: the most common pest of orchids, mainly parasitic on the stems and leaves of orchids. The shellfish eggs hatch into nymphs and form shells after a short period of crawling. Because the scale insect has a waxy shell, the general pesticide is difficult to enter, and the prevention and control is more difficult. It is best to spray 50% omethoate emulsion, 50% malathion emulsion, 25% imidophos emulsion or 80% dichlorvos EC in the peak egg incubation period. The concentration is 1000 times, once every 5 to 7 days, more than 3 times in a row. Red spider: occurs in places with strong light, dryness and high temperature. Control methods: in cultivation and management, pay attention to ventilation and increase humidity. Drug control, can spray 40% dicofol, 80% dichlorvos EC, 40% omethoate 1000 times, spray several times in a row. Whitefly: the whitefly is small and waxy powdery all over the body, which brings difficulties to prevention and control. Chemical control: spraying 2.5% deltamethrin, 10% permethrin, 20% dimethrin and other 2000 times solution has better control effect. Or 40% omethoate, 80% dichlorvos and 50% marathon emulsion also have good control effects on adults and larvae. Snails and slugs: when you see bright transparent mucus lines on the edge of the basin and on the bench, it indicates the activity of such mollusks. Prevention and control methods: poison bait, using wheat bran mixed with arsenic, pardon 100 insects, etc., scattered in the places where these animals move. Or sprinkle with quicklime and saturated salt water.