Integrated Control of Flower Diseases and insect pests in protected area

The large-scale development of protected cultivation provides convenient conditions for the annual production of flowers with ornamental as the target. However, the special environmental conditions of high temperature and humidity also provide an occasion for the mass reproduction and spread of diseases and insect pests. The occurrence and development of flower diseases and insect pests in protected land has its own characteristics, which is different from that in open field. Flowers as a kind of ornamental products, once infected with diseases and insect pests, some or all of their ornamental value will be lost, and it will be difficult to achieve satisfactory results by adopting a single control method. Therefore, the prevention and control of flowers' diseases and insect pests in protected areas must adhere to the policy of "prevention is more important than control", give full play to the effectiveness of comprehensive control, and control diseases and insect pests below the permitted degree of flower ornamental value. On the basis of full investigation and combined with several years' production experience, this paper discusses the occurrence regularity and comprehensive control countermeasures of the main infectious diseases and insect pests of flowers in protected areas, in order to provide scientific basis for the comprehensive control of diseases and insect pests in protected areas.

1 main diseases and insect pests of flowers in protected areas and their occurrence conditions

one. 1 main diseases and their occurrence conditions

(1) Botrytis cinerea is the most common and harmful fungal disease in protected flowers. Under the condition of moist and low temperature, it is very easy to occur. The symptoms are blight, canker, erosion of organs such as bulbs, bulbs and seeds, sudden fall of seedlings, etc., which often occur at the leaf tip and leaf edge. In the initial stage of the disease, the disease is mostly watery freckles, and in the later stage, it is often covered with gray mildew layer, and the host field is very wide, mainly harming cyclamen, begonia and so on.

(2) powdery mildew: mostly harmful to leaves, branches, flower organs and tender shoots. At the initial stage of the disease, the disease grew out of a layer of white powdery mildew and turned gray in the later stage. In the luxuriant growing season, high temperature and heavy rain, more nitrogen fertilizer, high planting density, lack of light or poor ventilation are conducive to the occurrence of diseases. Mainly harmful to rose, melon and leaf chrysanthemum and so on.

(3) anthrax: it is mainly harmful leaves and stems, at the beginning of the disease, the disease is mostly round, oval reddish brown freckles, and then expand into dark brown spots, the center of the spots produce striated small black spots, the edge is dark green; when the stem is sick, often produce round or nearly round light brown spots. It is mainly caused by overly dense potted flowers, infected leaves, high temperature and stuffy heat and poor ventilation. Mainly harm orchids, jasmine, Wan young and other foliage plants.

(4) Leaf spot, including black spot, brown spot, ring spot, etc., is caused by local infection, local necrosis of leaves and various colors and shapes of disease spots or perforations. There are all kinds of dots or mildew layers on the disease spot. It often occurs under the conditions of low temperature and foggy, poor ventilation and light transmission, extensive management and so on. It is mainly harmful to rose, gentleman orchid, camellia and foliage plants.

(5) Mosaic virus disease is a worldwide disease, mainly harmful to leaves and flower organs. In the early stage of the disease, the leaves began to fade and turn brown gradually, and the diseased leaves were yellowed and twisted, which was mainly caused by the seedling virus. It mainly harms Gladiolus, cyclamen, carnation and so on.

(6) bacterial erosion mostly occurs on succulent tissues, namely bulbs, bulbs and tubers. The disintegration of the disease part is characterized by the disintegration of tissue and the flow of foul-smelling sap. The environment with high temperature and humidity and more nitrogen fertilizer is conducive to occurrence and popularity. It mainly harms cyclamen, iris, gentleman orchid and so on.

one. 2 main insect pests and their occurrence conditions

Aphids, whitefly, red spiders and scale insects are the four major pests in the protected land.

The main results are as follows: (1) aphids are harmed by adults and nymphs gathering on shoots and young leaves to absorb juice, the damaged leaves often curl, the buds are not easy to expand, and the honeydew secreted by them can easily lead to coal fouling disease and virus disease. It is easy to occur when the climate is monotonous and the temperature is suitable. It mainly harms lilies, melon and leaf chrysanthemum, tulips and so on.

(2) White whitefly, also known as small white moth, is one of the key insects that damage flowers. Adults or nymphs gather at the back of the young leaves of the host to suck juice, and the damaged leaves fade, turn yellow, wilt, and even die. Honeydew secreted by adults and larvae is easy to induce coal pollution and virus. Breeds and harms in the greenhouse all the year round. It mainly harms rhododendron, rose, jasmine and so on.

(3) Red spiders often feed on the back of the leaves, damaging the leaf tissue, often making the leaves green, showing freckles, patches, or curling or wrinkling, and in serious cases, all the leaves are scorched, like roasting. It is easy to occur under monotonous conditions with high temperature. Mainly harmful to rose, rhododendron and so on.

(4) there are many species of scale insects, which are harmful to nymphs and female adults sucking juice at the shoot and leaf dorsal midvein, which is easy to cause the leaves and branches to dry up. In addition to pricking the juice and weakening the growth potential, it also induces coal fouling disease, which is harmful all the year round in the greenhouse. It mainly harms Michelia, Haitong, banyan, camellia and so on.

2 comprehensive prevention and control skills

two. 1 to cultivate strong seedlings without disease and insect pests

Dignified quarantine of seeds, seedlings and bulbs before sowing, timely adoption of drug disinfection and connection with warm water soaking, to prevent provenance from carrying bacteria, to do a good job in environmental sanitation in protected areas, and to completely eliminate residual plants, fallen leaves and weeds, reduce the habitat of diseases and insect pests To strengthen the seedling management, the density of flowers and trees should not be too high when planting or placing, release and refine the seedlings in time, control the excessive growth of seedlings, improve the stress resistance of seedlings, and find that diseased plants can be pulled out at any time. Through the above methods, the variety of pests can be reduced by about 50%.

two. (2) cultivation control

The main results are as follows: (1) the cultivated nutritious soil should be exposed to the sun before planting, or pentachloronitrobenzene and other chemicals should be used to solve the soil to prevent carrying germs and eggs. At the same time, the application of mature organic fertilizer can not only improve the microbial antagonism around the rhizosphere, but also reduce the occurrence of blight and quenching disease.

(2) crop rotation. Rotating planting of different varieties of flowers can effectively reduce the occurrence of soil-borne diseases such as blight, anthracnose and Sclerotinia sclerotiorum.

(3) High border cultivation can be irrigated by sprinkler irrigation, and the aisle is covered with crop straw, which can reduce the relative humidity of greenhouse and improve the performance of ventilation and light transmission, so as to reduce the probability of disease.

(4) rational management of water and fertilizer. According to the varieties and habits of different varieties of flowers, scientifically cooperate with fertilization, adjust the growth potential of flowers, strengthen the ability of resistance to diseases and insect pests, and promote the growth of flowers. Watering time, as far as possible to make the water temperature close to the soil temperature is appropriate. The spring and autumn season should be about 10:00 and after 3 o'clock in the afternoon, morning or dusk in summer and noon in winter, which can also alleviate the relative humidity in the protected area and reduce the frequency of diseases and insect pests.

(5) the greenhouse can be covered with non-dripping film or antifogging PVC film, which can reduce indoor relative humidity, increase light transmittance by 15% ℃, increase thermal insulation performance by 2% and 3%, and reduce the occurrence of diseases and insect pests.

two. (3) Ecological regulation and control

Strengthen environmental control, timely ventilation, improve the temperature and humidity in the protected area, as far as possible so that flower leaves do not dew, usually the temperature 20 ℃ 25 Mel, air relative humidity 60% Mel 70%, can ensure that there are no water droplets. This can reduce the occurrence of diseases such as gray mildew and downy mildew. The variable temperature management should be adopted in the protected area, because the temperature change range of the protected area is relatively large, and the regulation and control should be strengthened, so that the pathogen can not germinate and invade smoothly. The high temperature and the temperature above 28 ℃ are disadvantageous to the sporulation of downy mildew and Botrytis cinerea, and the higher temperature can kill the pathogens. The proper high temperature can also activate the defense enzymes in the body, thus improving the resistance of the plant. When the greenhouse temperature reached 35 ℃ and 40 min in sunny day, the greenhouse was stuffed for 2 hours, which could inhibit downy mildew and gray mildew to some extent.

two. 4. Biological control

Where conditions permit, biological control methods should be taken on their own initiative. The aphid wasp is the internal parasite of whitefly whitefly. When there are two whitefly heads per plant in the greenhouse, 2800 aphids / 667m2 are released, once every 10 days, lasting twice, and the control effect can reach 80%. Penicillium can also be used to control greenhouse whitefly, and protect it when seeing aphid flies, lacewings, ladybugs and other natural enemies, which can effectively improve the effect of biological control.

two. 5 physical prevention and cure

Heat treatment and other methods can effectively control diseases and insect pests, such as Gladiolus corm soaked in 55 ℃ hot water 30min to control Fusarium dry rot and other diseases. The silver-gray reflective film can be used to drive out aphids, and the principle of silver tin foil reflection can be used to resist the migration of aphids, or make use of the yellowing of aphids and whitefly to set up a yellow board on one side of the greenhouse wall or at the top of the plant 10-20cm or hang yellow adhesive strips at the vents for trapping and killing.

two. 6 chemical control

The chemical control of flower diseases and insect pests in protected areas should be based on the principle of "prevention is more important than control". The target diseases and pests should be alternately sprayed with bactericides such as chlorothalonil, methyl thiophanate and Yifanke, and insecticides such as quick-killing insecticides, dichlorvos, mites and other insecticides, usually spraying 2 hands three times a month, or fumigating with aerosol when the greenhouse is closed at dusk, which saves both labor and effort, disperses evenly, and suppresses the defect of uneven spray. In the greenhouse in winter, disease prevention is the main method. 20% chlorothalonil smoke remover can be used on schedule, 250g per 667m2 is ignited evenly, and fumigated and sterilized, which can avoid the occurrence of diseases in a large area. The following measures should be taken for sudden diseases and insect pests:

two. six. 1 prevention and control of major diseases

(1) Botrytis cinerea, anthracnose and blight: at the initial stage of the disease, control with 75% chlorothalonil soluble powder or 1500 times of 70% methyl topiramate powder.

(2) powdery mildew: the powdery mildew was sprayed with 2000 times of Fenghuanning for 3 times, especially sensitive to "sulfur" for powdery mildew bacteria, 0 sulfur powder per 250-300m2. 25kg + sawdust 0. 5kg lit fumigation overnight, the control effect is good.

(3) bacterial soft rot: spraying or watering 3Mel with agricultural streptomycin for 4 times can effectively prevent the occurrence of the disease.

(4) Mosaic virus disease: doing a good job in the control of aphids and scale insects, and spraying ribavirin on time has a certain effect on the control of virus diseases.

(5) Leaf spot disease: use 25% carbendazim wettable powder 300 mi 600 times once every 10 days, or use 25% carbendazim wet powder 2000 times solution, spray once a month, the effect is good.

two. six. 2 prevention of major insect pests

(1) aphids: 3000 times solution with 20% quick kill or 2. 5% deltamethrin 5000 times solution control, can also use 22% dichlorvos smoke agent 0. 3kg/667m2 or 10% aphid smoke agent airtight fumigation overnight, the method is simple, and has a special effect on controlling aphids.

(2) whitefly: control with 3000 times of imidacloprid and 1500 times of 25% buprofezin wettable powder or 2. The mixture of 5000 times of Uranus EC has a special effect on the control of whitefly. The insecticide should be sprayed in the morning or dusk to continue the control of 2mi for 3 times, which can not only alleviate the resistance of whitefly, but also improve the control effect.

(3) Red spiders and scale insects: on the basis of artificial disinfestation, 1000 times of trichlorfon EC and 40% omethoate EC were used. Or 20% acarine EC 3000 Mel 4000 times, and add a small amount of washing powder to spray cloth evenly, spray once every 7 mi 10 days, continue to spray 3 Mel 4 times. The control effect of 1000 times of dicofol can also reach more than 90%. In addition, fumigation with 250g/667m2 for 5 hours in the protected area had a certain control effect on whitefly, red spider and scale insects.

3 summary

The occurrence of main diseases and insect pests of flowers in protected areas is closely related to the specific environmental conditions of high temperature and humidity. The prevention and control of diseases and insect pests should be based on the principle of "prevention is more important than control", take cultivation prevention as the basis, strengthen the regulation and control of ecological environment, and take the initiative to adopt biological control, physical control and timely use of low-toxic pesticides, etc. according to the principle of timely control of diseases and insect pests of different varieties, we should control the occurrence of diseases and insect pests and effectively improve the ornamental value of flowers, so as to achieve high benefit of flower production.