(1) The occurrence and prevention of major diseases of vegetables 1. Vegetable downy mildew: can damage cruciferous vegetables, cucumbers, lettuce, onions, spinach, broccoli and so on. Distribution and damage: Downy mildew is a kind of relatively important and harmful disease. This kind of more important and harmful diseases, the symptoms of this kind of disease, the regularity, the biological characteristics and pathogenesis of pathogens The environmental conditions are similar, causing serious damage when the disease is prevalent. Symptoms: It can develop in the whole growth period, and leaves, stems, pedicels, seed pods and Other parts can be infiltrated by pathogens. On the leaves, yellowish green lesions with unclear edges occur at first, and gradually turn yellow to brown. After the lesions are enlarged, they are restricted by the veins to become polygonal. When the humidity in the field is high, a layer of white frosty mildew is produced in the back part of the leaf. The lesions often heal each other into pieces, and finally the whole leaves are dead. The disease occurs first on the leaves closer to the ground, and the young leaves rarely occur.
The main symptoms of the symptoms of vegetable downy mildew:
1 is mainly harmful to the leaves, the lesions are initially fading green or yellowish, without a distinct circumference;
2 on the surface of the diseased part (the leaves are mainly on the back), the color of the mildew layer (spore sac and spore stalk) grows;
3 The onset site starts from the blade closer to the ground and gradually expands upward or inward, and the young leaves rarely occur. Pathogen: caused by fungal infection, the parasitic nature of these pathogens is obligate parasites, which can only absorb nutrients from living tissues and fines, and destroy host vegetable tissues and cells. Pathogenesis and environmental conditions: The oospores remain in the soil in the diseased body, or adhere to the surface of the seed for wintering. After wintering, by means of rainwater splashing, it is transmitted to the leaves closer to the ground to produce buds. The tube is subjected to the first dip dyeing. The climate is hot and cold, when it is sunny and rainy, the field is humid and the incidence is heavy.
Control method:
1 use resistant varieties;
2 seed treatment: 50% Fushuangmei or 75% chlorothalonil seed dressing, the dosage is 0.4% of the seed weight;
3 Clean the pastoral: rational rotation, open the compartment ditch, reduce the humidity and groundwater level in the field:
4 chemical control: in the early stage of the disease or the emergence of the central disease plant immediately spray, can be used 800 times liquid cream; Rui poison cream, ruthenium copper, 25% metalaxyl 1000 times liquid spray, with Hu special effects; can also use Dyson Ammonium, Daisen zinc, reductive 800 times liquid spray, spray on the back when spraying.
2. Vegetable disease: It can harm a variety of vegetables such as cucumber, melon, pepper, taro, potato, etc. The disease has an upward trend in recent years and is an important disease. If the environment is suitable, the disease will occur rapidly, often leading to the destruction of the whole field in a short period of time.
Symptoms: There are differences in symptoms due to different vegetable varieties:
1 Cucumber disease affects the stems and stems of the stems, and the leaves and fruits can also be harmed. The base of the stem initially showed green water immersion, and the upper leaves gradually withered, and finally the whole plant died. When the diseased plant is dead, the diseased leaves are still green, the stem is damaged, the diseased part is contracted and twisted, the upper branches and leaves are wilted, the leaves are damaged, and the dark green water-stained spots are initially formed, which are enlarged to be nearly circular. The lesions, the edges are not obvious, and the wet weather often causes the entire leaves to rot.
2 winter melon disease: damage to melons and leaves, leaves and vines. In the lower part of the melon, a yellow-brown water-soaked lesion appears, and the diseased part is sunken. The white spotted mildew on the spot is rotted and stinky. The leaf spot is yellowish brown, the edge is not obvious, the white mold is on, and the rainy and wet leaves rot.
3 Capsicum blight: Most of the adult stage occurs, the spot appears dark brown needle-like small points, and then rapidly expands, the diseased part is black, the main stem is damaged, the lesion can be extended to the branch, and the plant wilts and dies. Pathogen: fungal disease. Pathogenesis and environmental conditions: The bacteria overwinter in seeds and seed potatoes. Most of the diseases are spores and myceliums along with the sick plants in the winter. The pathogens after wintering are mainly caused by the splashing of rainwater. The granules overwintering pathogens are transmitted to the parasitic main body, invading the host under suitable climatic conditions to cause primary infiltration and reproduction, and can be re-infected by airflow, rainwater, etc. The factors affecting the onset include humidity, cultivation management level and variety disease resistance. Humidity is the main factor. Under humid environmental conditions, the disease is usually serious. All the terrain is low, the drainage is poor, the soil is sticky, and the water is stained after the rain. Or the land that leaks near the canal is seriously affected. Partial application of nitrogen fertilizer, management extensive, humidity and vegetable fields are also serious.
Control method:
1 high sorghum deep ditch to strengthen flood control;
2 rational rotation, increase the application of organic fertilizer;
3 use disease-resistant and disease-free seeds;
4 chemical control: timely spraying protection is a more effective measure to prevent the spread of the disease. Due to the short incubation period and rapid spread of the disease, it should be carried out before the onset of the disease. It can be sprayed with Bordeaux liquid cucumber 0.3%, pepper 0.5%, sputum and potato 1% concentration spray, can be sprayed with metalaxyl 500 times solution; Liquid, thiophanate, dikesone 1000 times liquid spray.
3. Vegetable wilt: It can harm crops such as pepper, tomato, cucumber, melon, loofah and watermelon.
Symptoms: Solanum is mainly expressed on the leaves closer to the ground. The leaves are yellow and then brown and dry, but the dead leaves are still not attached to the stems. Sometimes the yellow leaves appear only on one side of the stems or leaves. On the other side, the leaves are normal in color, and the stems are cut longitudinally or transversely, and the vascular bundles are brown. Cucumber wilt disease, in the early stage of the disease, the leaves at the base of the stem suddenly appear wilting, and it is easy to be confused by the performance caused by insufficient water supply to the leaves. The leaves are obvious around noon, and gradually return to normal in the evening, after several days in succession. The whole plant died and the leaves did not fall off. In wet conditions, the surface of the disease often produces white or pink mildew. Pathogenesis and environmental conditions: The pathogen remains in the soil over the winter with the residue of the diseased plant. It can be used for saprophytic life in the soil. The surface of the seed can also be carried with bacteria. The pathogen is mainly invaded by root wounds, and the pathogens in the seedling stage are infected until the flowering result of the adult plants. Symptoms, the soil of the vegetable field is sour, the soil is sticky, and the disease is low.
Control method:
1 Use disease-resistant, disease-free seeds for seed treatment;
2 rounds of change;
3 chemical control, spray with carbendazim or benzoate 800 times solution, 1000 times solution of mancozeb.
(4) Vegetable anthracnose: It can be a variety of crops such as melons, cruciferous vegetables, peppers, eggplants and kidney beans. Distribution and harm: The melon anthracnose disease in our province is an important disease on melon crops, and crops such as pepper and Chinese cabbage are heavier. Distribution is widespread, and there has been an upward trend in recent years.
Symptoms: If the melon anthracnose occurs in the seedling stage, the base of the stem of the seedling can be atrophied and discolored. Causes brown semicircular lesions on the edges of the leaves. The adult stage disease mainly affects the leaves, stems, and melons. The symptoms of different melons are slightly different. Pathogen: fungal disease. The pathogenesis and disease conditions: the pathogens are overwintered with the diseased plants on the residue, and some conidia are attached to the surface of the seeds for wintering. The bacteria are spread by rainwater, insects, etc., and enter the body directly through the parasitic surface in a suitable environment. Invasion from the wound, which spreads during the growth of the host plant. Environmental conditions are closely related to the severity of anthrax. Humidity is a major factor in the induction of anthrax. The melon anthracnose has a relative humidity of over 97%, and the temperature is about 24 °C. Capsicum anthracnose disease is also very serious in high temperature and high humidity environment, so it is most likely to occur in warm and humid weather.
Control method:
1Select disease-resistant and disease-free varieties;
2 Seeds are sterilized before sowing, soaked in warm soup, melons and peppers soaked in warm water at 55 ° C for 15 minutes, or soaked in 100 times formalin for 30 minutes;
3 turns to make a deep turn, causing the bacteria to die;
4 Reasonable close planting, pay attention to field drainage, rational fertilization, avoid mechanical injury or daily injury, and improve the disease resistance of host plants;
5 chemical control: can be used with thiophanate, carbendazim 700-800 times solution, Daisen zinc 800 times liquid spray control.
(5) Vegetable bacterial wilt: It can damage tomatoes, eggplant, potato, pepper and other crops. Tomato damage is the most serious, followed by eggplant and potato.
Symptoms: The tomato seedlings do not show symptoms. The plant grows to near flowering and begins to develop. First, the leaves are wilted. Later, the lower leaves are withered, the first day is wilting, and the evening is restored. Repeated for many days, the leaves are lighter, but still Keep the original color and die in about 7 days. Cross-section examination, squeezed by hand, can have milky white mucus oozing. Eggplant bacterial wilt, when the initial onset, the leaves of individual branches suddenly wilted, and some of the leaves are wilting, and some half of the leaves are wilting, and the other half of the leaves are normal. The color of the diseased leaves is lighter, and the diseased leaves gradually expand. After a few days, the leaves on the whole branches appear to be wilting. In the later stage, the leaves become brown and coke, shed or remain on the branches, and there are no obvious symptoms on the roots and stems. The stem cortex is peeled off and the xylem is brown. Pathogen: bacterial disease. The pathogenesis and disease conditions: the bacteria stay in the soil over the winter with the diseased plants, the bacteria can live on the residual plants, and can survive in the soil for 1-2 years. The bacteria infiltrate into the body from the root wounds of the plants, and the bacteria multiply in the conduits. The tube is blocked, the water can not rise, the stems and leaves die due to loss of water, the bacteria are spread by rain, farm tools, humans and animals. When there is too much rain, the humidity in the field and the acidity of the soil are high, and the weather turns fine after a long rain or heavy rain. The temperature has risen sharply and the incidence of bacterial wilt is more serious.
Control method:
1 round of rotation: the three-year rotation system is generally implemented in the general disease area;
2 adjust soil pH, apply more lime and grass ash;
3 Improve the cultivation techniques, adopt deep-ditch narrow-stem cultivation, cultivate strong seedlings, increase the application of phosphorus, potassium fertilizer and micro-fertilizer;
4 chemical control: the first found diseased plants, removed and destroyed, surrounded by lime disinfection, the initial stage of the disease spray 100-150ppM agricultural streptomycin or the enemy with two pairs of 500-1000 times liquid irrigation pocket.
(2) The occurrence and prevention of major pests in vegetables:
1. Small tiger (soilworm, silkworm): Small tiger is one of the important pests in vegetable seedlings. It is harmful to many crops. It is generally caused by the first generation of larvae. It is seen in May and June is the peak period. There are also occurrences in September-October, the heart or young leaves of the 1st and 2nd infested crops, and the 3rd instar larvae cut off the young stems of the crops, resulting in lack of seedlings and ridges. Morphological characteristics: the adult body is dark brown, the female moth is silky, the base of the male moth is one-half double-node, the rest are filiform, the front wing is gray-brown, and the front edge of the wing has a kidney-like pattern. First, there are black edges around each grain. The hind wings are grayish white and the wings are dark brown. Egg: hemisphere type, with vertical and horizontal flannel on the surface; larva: body yellow-brown to dark brown, obvious on the back line, extremely rough surface, dense black particles. The abdomen has a yellow-brown hard-skinned board with two distinct dark brown longitudinal bands.蛹: russet, shiny, 4-5 knots, the center of the front of the abdomen has a thick engraving point; 5-7 section of the abdomen of the abdomen also has a small engraved point. A pair of short thorns on the abdomen. Habits of life: 4-5 generations per year, with old larvae or crickets overwintering in the soil, one generation of cockroaches. There is daytime feeding before the age of 3, and after the third age, the feeding is controlled at the age of 1 and 2 years. Occurrence conditions: The number of small tigers is closely related to rainfall. In the autumn of the previous year, there were more rains, and there was a large amount of rain during the period from March to April. Generally, rivers, lakes, low-lying geothermal heat, poorly drained wetlands, and clays with a lot of water are more likely to occur in sandy sands.
Control method:
1 trap the adult, reduce the source of insects, use 3 parts of brown sugar, 3 parts of vinegar, 1 part of white, 10 parts of water, add 50% of dichlorvos or trichlorfon according to the total amount of 0.1%, and put it into the field with lure in the evening. The promotion of the old filter attractant to trap adult insects, the effect is very good, can be widely used.
2 Fine soil preparation, removal of weeds, elimination of the place where the tigers lay their eggs, and cutting off the source of early larvae's foodstuffs are important for reducing the damage of the tigers. Chemical control: prevention and treatment of 3rd instar larvae, emergence of holes in the seedlings, nicks and other murders, in the seedlings and surrounding weeds sprayed with hundreds of insects and dichlorvos 800 times liquid control. After the prevention and treatment of the three-toothed larvae, the tribes were mixed with fresh grass, vegetable leaves or fried coriander cakes and cotton cakes to make poisonous grass baits, and they were thrown into the field to lure in the evening. Artificially catching the larvae in the early morning in the morning around the vegetable field broken seedlings or in the residual hole.
2. Aphids: Aphids are world-class pests, and they have many types of crops. In addition to melons, they can also feed on beans, solanaceous, cruciferous, malvaceae, etc., with adult and nymphs on the back of the leaves. The young shoots suck on the young stems, the leaves are damaged, causing the leaves to curl up, delaying the growth period. In severe cases, the seedlings are wilting and dry, and they are the main spreaders of viral diseases, which can also increase the occurrence and prevalence of stem blight. Occurrence characteristics: Aphids have high fertility, and occur in multiple generations a year, especially during the dry season.
Control method:
1 Eliminate the locusts on the wintering host, when the wintering host and the winged cockroach reach 30%, spray phoxim or dimethoate 1000 times solution;
2 Remove weeds, combine winter and spring with fertilizer to remove weeds inside and outside the field, along the side of the road, on the side of the road, and on the roadside to eliminate the source of insects. Chemical control: When the mites occur in the spotting stage, they can be sprayed with dimethoate, glutinous pine, 1000 times liquid, and can also be sprayed with enemy killing and quick killing 3000-4000 times.
3. Tobacco budworm (Sphingidae moth) mainly harms peppers, beans and other crops on vegetable crops. Pepper is the most seriously damaged. The larvae invade the harm of the fruit, affect the yield and quality of pepper, spread soft rot, and cause serious damage. Occurrence characteristics: Changsha area occurs 4 generations a year, a few occur in 5 generations, and the soil is overwintered in the soil room of about 1 inch in the pepper field. The overwintering period of adults is in the middle of May and the middle of June to the beginning of June. The egg incubation period is in early June, the larval damage is in the middle of June, the larval damage is in the middle of June, and the moth is in mid-July. The second generation of egg incubation period is in the middle and late July, and the larval damage is in the late July, and the moth is in mid-August. The third generation of eggs is in the middle and late August, and the larval damage is in the middle and late August. The fourth generation of eggs is in the mid-September period, and from the end of September to the beginning of October, most of the fourth generation of mature larvae enter the soil for wintering. During the occurrence of tobacco budworms, the overlapping phenomenon of generations is very obvious. The number of occurrences during the year from July to August is large and the damage is serious. Living habits: Adults inhabit the peppers and tobacco leaves during the daytime, nighttime activities, and tend to black light and willow branches. Adults like to lay eggs on peppers and tobacco leaves. After the larvae hatch, they eat the flower buds after eating the egg shells. After 3 years of age, the hazelnuts began to have a habit of turning fruits into harm. Rainwater is an important factor affecting the occurrence of tobacco budworms. Rainy years are not conducive to occurrence, and drought years are conducive to occurrence.
Control method:
1 winter tillage;
2 promptly remove the worm fruit, eliminate the larvae in the fruit, and prevent the fruit from being damaged;
3 planting smoke to trap the overwintering adults to lay eggs, concentrated elimination;
â‘£ black light, willow branches to trap and kill adults. Chemical control: 8000 times of trichlorfon, enemy killing, rapid killing and killing 3000 times liquid spray, it is necessary to master the larva before breaking into the fruit, while the enemy kills, kills and kills the other pesticides alternately. otherwise it will cause yellow tea mite outbreak.
â’‹ yellow tea mite (white spiders) horseleech yellow tea, can damage a variety of vegetable crops in recent years, serious harm after midnight, a great influence on the yield and quality of pepper, resulting in losses of up to 40%. Features occur: Can natural winter in the south, fecundity, body is very small, usually naked eye do not look closely, it is difficult to find. Latus tender chemotactic properties, so inhabit parts feeding damage in young, young leaves the back Qixi feeding habitat, pepper suffer dorsal grease-like shape, gradient brown, margin downward curl, young stem becomes brown, victims of serious small plant clumps, flower and fruit drop, forming bald, fruit stalk also become brown and dull, the fruits of growth arrest and hardening. After the eggplant was damaged, the upper part of the ground was stiff, the back of the leaf was gray-brown or yellow-brown, the oily shape, the leaf edge curled downward, the stem, the stem, the stem and the fruit became grayish brown, and the eggplant was seriously damaged after the bud stage. Can't bloom. Most of the young fruit is yellowish in the umbilicus after falling flowers. As the fruit grows, it gradually turns dark brown, the peel is cracked, and the seeds are bare.
Control method:
1 Remove the weeds in the field, clean the fields, and clear the litter in time after harvesting the vegetables to eliminate the insect source.
2 Chemical control, starting from the end of May, focus on the inspection of the side of the house, the dam and the mountain side of the field to find the center of the hazard, should be sprayed in a timely manner, focus on the treatment, every 10-15 days from late June to August Spray once, for 3-4 times in a row, the main focus of spraying is the upper part of the plant, especially the back of the young leaves and the tender stems, flowers and young fruits can be selected with 1000 times of dicofol; killing 800 times liquid spray; have good results.
5. Melon is mainly harmful to cucumber, melon, loofah, bitter gourd and other melon crops. It is particularly harmful to melon, and the larvae harm leaves, tops and smashed melons, and the leaves are seriously damaged. Occurrence characteristics: The melon wild carp occurs 6 generations a year, and the old larvae and cockroaches overwinter in the dead branches and leaves. Generally, they begin to see in May, and begin to harm at the end of May. The amount of occurrence in the three months from July to September is large at the end of October. Along the larvae can be seen on melon, cucumber and loofah, the eggs are mostly produced on the back of the leaves, and the scattered or several grains are produced together. The larvae of the 3rd instar larvae sew the leaves to conceal and hide in them. In severe cases, The leaves can be eaten light, leaving only veins. The larva not only eats the young fruit and flowers of the melon, but also invades the melon. The larva is lively. After a little shock, the silk is drooping and the other is transferred. After the larva is matured, it will be white and sputum in the victim, or it will be phlegm in the topsoil.
Control method:
1 The prevention and control of melon wild scorpion should be applied at the peak of hatching of larvae. You can choose to spray 1000 times of dimethoate or trichlorfon, killing or killing 4000 times liquid spray.
2 manually remove the damaged leaf and eliminate the larvae in the leaf;
3 After harvesting the melon crops, it is necessary to collect and burn the dead vines and leaves in time to eliminate the insect source.
From: China Agriculture Network
The main symptoms of the symptoms of vegetable downy mildew:
1 is mainly harmful to the leaves, the lesions are initially fading green or yellowish, without a distinct circumference;
2 on the surface of the diseased part (the leaves are mainly on the back), the color of the mildew layer (spore sac and spore stalk) grows;
3 The onset site starts from the blade closer to the ground and gradually expands upward or inward, and the young leaves rarely occur. Pathogen: caused by fungal infection, the parasitic nature of these pathogens is obligate parasites, which can only absorb nutrients from living tissues and fines, and destroy host vegetable tissues and cells. Pathogenesis and environmental conditions: The oospores remain in the soil in the diseased body, or adhere to the surface of the seed for wintering. After wintering, by means of rainwater splashing, it is transmitted to the leaves closer to the ground to produce buds. The tube is subjected to the first dip dyeing. The climate is hot and cold, when it is sunny and rainy, the field is humid and the incidence is heavy.
Control method:
1 use resistant varieties;
2 seed treatment: 50% Fushuangmei or 75% chlorothalonil seed dressing, the dosage is 0.4% of the seed weight;
3 Clean the pastoral: rational rotation, open the compartment ditch, reduce the humidity and groundwater level in the field:
4 chemical control: in the early stage of the disease or the emergence of the central disease plant immediately spray, can be used 800 times liquid cream; Rui poison cream, ruthenium copper, 25% metalaxyl 1000 times liquid spray, with Hu special effects; can also use Dyson Ammonium, Daisen zinc, reductive 800 times liquid spray, spray on the back when spraying.
2. Vegetable disease: It can harm a variety of vegetables such as cucumber, melon, pepper, taro, potato, etc. The disease has an upward trend in recent years and is an important disease. If the environment is suitable, the disease will occur rapidly, often leading to the destruction of the whole field in a short period of time.
Symptoms: There are differences in symptoms due to different vegetable varieties:
1 Cucumber disease affects the stems and stems of the stems, and the leaves and fruits can also be harmed. The base of the stem initially showed green water immersion, and the upper leaves gradually withered, and finally the whole plant died. When the diseased plant is dead, the diseased leaves are still green, the stem is damaged, the diseased part is contracted and twisted, the upper branches and leaves are wilted, the leaves are damaged, and the dark green water-stained spots are initially formed, which are enlarged to be nearly circular. The lesions, the edges are not obvious, and the wet weather often causes the entire leaves to rot.
2 winter melon disease: damage to melons and leaves, leaves and vines. In the lower part of the melon, a yellow-brown water-soaked lesion appears, and the diseased part is sunken. The white spotted mildew on the spot is rotted and stinky. The leaf spot is yellowish brown, the edge is not obvious, the white mold is on, and the rainy and wet leaves rot.
3 Capsicum blight: Most of the adult stage occurs, the spot appears dark brown needle-like small points, and then rapidly expands, the diseased part is black, the main stem is damaged, the lesion can be extended to the branch, and the plant wilts and dies. Pathogen: fungal disease. Pathogenesis and environmental conditions: The bacteria overwinter in seeds and seed potatoes. Most of the diseases are spores and myceliums along with the sick plants in the winter. The pathogens after wintering are mainly caused by the splashing of rainwater. The granules overwintering pathogens are transmitted to the parasitic main body, invading the host under suitable climatic conditions to cause primary infiltration and reproduction, and can be re-infected by airflow, rainwater, etc. The factors affecting the onset include humidity, cultivation management level and variety disease resistance. Humidity is the main factor. Under humid environmental conditions, the disease is usually serious. All the terrain is low, the drainage is poor, the soil is sticky, and the water is stained after the rain. Or the land that leaks near the canal is seriously affected. Partial application of nitrogen fertilizer, management extensive, humidity and vegetable fields are also serious.
Control method:
1 high sorghum deep ditch to strengthen flood control;
2 rational rotation, increase the application of organic fertilizer;
3 use disease-resistant and disease-free seeds;
4 chemical control: timely spraying protection is a more effective measure to prevent the spread of the disease. Due to the short incubation period and rapid spread of the disease, it should be carried out before the onset of the disease. It can be sprayed with Bordeaux liquid cucumber 0.3%, pepper 0.5%, sputum and potato 1% concentration spray, can be sprayed with metalaxyl 500 times solution; Liquid, thiophanate, dikesone 1000 times liquid spray.
3. Vegetable wilt: It can harm crops such as pepper, tomato, cucumber, melon, loofah and watermelon.
Symptoms: Solanum is mainly expressed on the leaves closer to the ground. The leaves are yellow and then brown and dry, but the dead leaves are still not attached to the stems. Sometimes the yellow leaves appear only on one side of the stems or leaves. On the other side, the leaves are normal in color, and the stems are cut longitudinally or transversely, and the vascular bundles are brown. Cucumber wilt disease, in the early stage of the disease, the leaves at the base of the stem suddenly appear wilting, and it is easy to be confused by the performance caused by insufficient water supply to the leaves. The leaves are obvious around noon, and gradually return to normal in the evening, after several days in succession. The whole plant died and the leaves did not fall off. In wet conditions, the surface of the disease often produces white or pink mildew. Pathogenesis and environmental conditions: The pathogen remains in the soil over the winter with the residue of the diseased plant. It can be used for saprophytic life in the soil. The surface of the seed can also be carried with bacteria. The pathogen is mainly invaded by root wounds, and the pathogens in the seedling stage are infected until the flowering result of the adult plants. Symptoms, the soil of the vegetable field is sour, the soil is sticky, and the disease is low.
Control method:
1 Use disease-resistant, disease-free seeds for seed treatment;
2 rounds of change;
3 chemical control, spray with carbendazim or benzoate 800 times solution, 1000 times solution of mancozeb.
(4) Vegetable anthracnose: It can be a variety of crops such as melons, cruciferous vegetables, peppers, eggplants and kidney beans. Distribution and harm: The melon anthracnose disease in our province is an important disease on melon crops, and crops such as pepper and Chinese cabbage are heavier. Distribution is widespread, and there has been an upward trend in recent years.
Symptoms: If the melon anthracnose occurs in the seedling stage, the base of the stem of the seedling can be atrophied and discolored. Causes brown semicircular lesions on the edges of the leaves. The adult stage disease mainly affects the leaves, stems, and melons. The symptoms of different melons are slightly different. Pathogen: fungal disease. The pathogenesis and disease conditions: the pathogens are overwintered with the diseased plants on the residue, and some conidia are attached to the surface of the seeds for wintering. The bacteria are spread by rainwater, insects, etc., and enter the body directly through the parasitic surface in a suitable environment. Invasion from the wound, which spreads during the growth of the host plant. Environmental conditions are closely related to the severity of anthrax. Humidity is a major factor in the induction of anthrax. The melon anthracnose has a relative humidity of over 97%, and the temperature is about 24 °C. Capsicum anthracnose disease is also very serious in high temperature and high humidity environment, so it is most likely to occur in warm and humid weather.
Control method:
1Select disease-resistant and disease-free varieties;
2 Seeds are sterilized before sowing, soaked in warm soup, melons and peppers soaked in warm water at 55 ° C for 15 minutes, or soaked in 100 times formalin for 30 minutes;
3 turns to make a deep turn, causing the bacteria to die;
4 Reasonable close planting, pay attention to field drainage, rational fertilization, avoid mechanical injury or daily injury, and improve the disease resistance of host plants;
5 chemical control: can be used with thiophanate, carbendazim 700-800 times solution, Daisen zinc 800 times liquid spray control.
(5) Vegetable bacterial wilt: It can damage tomatoes, eggplant, potato, pepper and other crops. Tomato damage is the most serious, followed by eggplant and potato.
Symptoms: The tomato seedlings do not show symptoms. The plant grows to near flowering and begins to develop. First, the leaves are wilted. Later, the lower leaves are withered, the first day is wilting, and the evening is restored. Repeated for many days, the leaves are lighter, but still Keep the original color and die in about 7 days. Cross-section examination, squeezed by hand, can have milky white mucus oozing. Eggplant bacterial wilt, when the initial onset, the leaves of individual branches suddenly wilted, and some of the leaves are wilting, and some half of the leaves are wilting, and the other half of the leaves are normal. The color of the diseased leaves is lighter, and the diseased leaves gradually expand. After a few days, the leaves on the whole branches appear to be wilting. In the later stage, the leaves become brown and coke, shed or remain on the branches, and there are no obvious symptoms on the roots and stems. The stem cortex is peeled off and the xylem is brown. Pathogen: bacterial disease. The pathogenesis and disease conditions: the bacteria stay in the soil over the winter with the diseased plants, the bacteria can live on the residual plants, and can survive in the soil for 1-2 years. The bacteria infiltrate into the body from the root wounds of the plants, and the bacteria multiply in the conduits. The tube is blocked, the water can not rise, the stems and leaves die due to loss of water, the bacteria are spread by rain, farm tools, humans and animals. When there is too much rain, the humidity in the field and the acidity of the soil are high, and the weather turns fine after a long rain or heavy rain. The temperature has risen sharply and the incidence of bacterial wilt is more serious.
Control method:
1 round of rotation: the three-year rotation system is generally implemented in the general disease area;
2 adjust soil pH, apply more lime and grass ash;
3 Improve the cultivation techniques, adopt deep-ditch narrow-stem cultivation, cultivate strong seedlings, increase the application of phosphorus, potassium fertilizer and micro-fertilizer;
4 chemical control: the first found diseased plants, removed and destroyed, surrounded by lime disinfection, the initial stage of the disease spray 100-150ppM agricultural streptomycin or the enemy with two pairs of 500-1000 times liquid irrigation pocket.
(2) The occurrence and prevention of major pests in vegetables:
1. Small tiger (soilworm, silkworm): Small tiger is one of the important pests in vegetable seedlings. It is harmful to many crops. It is generally caused by the first generation of larvae. It is seen in May and June is the peak period. There are also occurrences in September-October, the heart or young leaves of the 1st and 2nd infested crops, and the 3rd instar larvae cut off the young stems of the crops, resulting in lack of seedlings and ridges. Morphological characteristics: the adult body is dark brown, the female moth is silky, the base of the male moth is one-half double-node, the rest are filiform, the front wing is gray-brown, and the front edge of the wing has a kidney-like pattern. First, there are black edges around each grain. The hind wings are grayish white and the wings are dark brown. Egg: hemisphere type, with vertical and horizontal flannel on the surface; larva: body yellow-brown to dark brown, obvious on the back line, extremely rough surface, dense black particles. The abdomen has a yellow-brown hard-skinned board with two distinct dark brown longitudinal bands.蛹: russet, shiny, 4-5 knots, the center of the front of the abdomen has a thick engraving point; 5-7 section of the abdomen of the abdomen also has a small engraved point. A pair of short thorns on the abdomen. Habits of life: 4-5 generations per year, with old larvae or crickets overwintering in the soil, one generation of cockroaches. There is daytime feeding before the age of 3, and after the third age, the feeding is controlled at the age of 1 and 2 years. Occurrence conditions: The number of small tigers is closely related to rainfall. In the autumn of the previous year, there were more rains, and there was a large amount of rain during the period from March to April. Generally, rivers, lakes, low-lying geothermal heat, poorly drained wetlands, and clays with a lot of water are more likely to occur in sandy sands.
Control method:
1 trap the adult, reduce the source of insects, use 3 parts of brown sugar, 3 parts of vinegar, 1 part of white, 10 parts of water, add 50% of dichlorvos or trichlorfon according to the total amount of 0.1%, and put it into the field with lure in the evening. The promotion of the old filter attractant to trap adult insects, the effect is very good, can be widely used.
2 Fine soil preparation, removal of weeds, elimination of the place where the tigers lay their eggs, and cutting off the source of early larvae's foodstuffs are important for reducing the damage of the tigers. Chemical control: prevention and treatment of 3rd instar larvae, emergence of holes in the seedlings, nicks and other murders, in the seedlings and surrounding weeds sprayed with hundreds of insects and dichlorvos 800 times liquid control. After the prevention and treatment of the three-toothed larvae, the tribes were mixed with fresh grass, vegetable leaves or fried coriander cakes and cotton cakes to make poisonous grass baits, and they were thrown into the field to lure in the evening. Artificially catching the larvae in the early morning in the morning around the vegetable field broken seedlings or in the residual hole.
2. Aphids: Aphids are world-class pests, and they have many types of crops. In addition to melons, they can also feed on beans, solanaceous, cruciferous, malvaceae, etc., with adult and nymphs on the back of the leaves. The young shoots suck on the young stems, the leaves are damaged, causing the leaves to curl up, delaying the growth period. In severe cases, the seedlings are wilting and dry, and they are the main spreaders of viral diseases, which can also increase the occurrence and prevalence of stem blight. Occurrence characteristics: Aphids have high fertility, and occur in multiple generations a year, especially during the dry season.
Control method:
1 Eliminate the locusts on the wintering host, when the wintering host and the winged cockroach reach 30%, spray phoxim or dimethoate 1000 times solution;
2 Remove weeds, combine winter and spring with fertilizer to remove weeds inside and outside the field, along the side of the road, on the side of the road, and on the roadside to eliminate the source of insects. Chemical control: When the mites occur in the spotting stage, they can be sprayed with dimethoate, glutinous pine, 1000 times liquid, and can also be sprayed with enemy killing and quick killing 3000-4000 times.
3. Tobacco budworm (Sphingidae moth) mainly harms peppers, beans and other crops on vegetable crops. Pepper is the most seriously damaged. The larvae invade the harm of the fruit, affect the yield and quality of pepper, spread soft rot, and cause serious damage. Occurrence characteristics: Changsha area occurs 4 generations a year, a few occur in 5 generations, and the soil is overwintered in the soil room of about 1 inch in the pepper field. The overwintering period of adults is in the middle of May and the middle of June to the beginning of June. The egg incubation period is in early June, the larval damage is in the middle of June, the larval damage is in the middle of June, and the moth is in mid-July. The second generation of egg incubation period is in the middle and late July, and the larval damage is in the late July, and the moth is in mid-August. The third generation of eggs is in the middle and late August, and the larval damage is in the middle and late August. The fourth generation of eggs is in the mid-September period, and from the end of September to the beginning of October, most of the fourth generation of mature larvae enter the soil for wintering. During the occurrence of tobacco budworms, the overlapping phenomenon of generations is very obvious. The number of occurrences during the year from July to August is large and the damage is serious. Living habits: Adults inhabit the peppers and tobacco leaves during the daytime, nighttime activities, and tend to black light and willow branches. Adults like to lay eggs on peppers and tobacco leaves. After the larvae hatch, they eat the flower buds after eating the egg shells. After 3 years of age, the hazelnuts began to have a habit of turning fruits into harm. Rainwater is an important factor affecting the occurrence of tobacco budworms. Rainy years are not conducive to occurrence, and drought years are conducive to occurrence.
Control method:
1 winter tillage;
2 promptly remove the worm fruit, eliminate the larvae in the fruit, and prevent the fruit from being damaged;
3 planting smoke to trap the overwintering adults to lay eggs, concentrated elimination;
â‘£ black light, willow branches to trap and kill adults. Chemical control: 8000 times of trichlorfon, enemy killing, rapid killing and killing 3000 times liquid spray, it is necessary to master the larva before breaking into the fruit, while the enemy kills, kills and kills the other pesticides alternately. otherwise it will cause yellow tea mite outbreak.
â’‹ yellow tea mite (white spiders) horseleech yellow tea, can damage a variety of vegetable crops in recent years, serious harm after midnight, a great influence on the yield and quality of pepper, resulting in losses of up to 40%. Features occur: Can natural winter in the south, fecundity, body is very small, usually naked eye do not look closely, it is difficult to find. Latus tender chemotactic properties, so inhabit parts feeding damage in young, young leaves the back Qixi feeding habitat, pepper suffer dorsal grease-like shape, gradient brown, margin downward curl, young stem becomes brown, victims of serious small plant clumps, flower and fruit drop, forming bald, fruit stalk also become brown and dull, the fruits of growth arrest and hardening. After the eggplant was damaged, the upper part of the ground was stiff, the back of the leaf was gray-brown or yellow-brown, the oily shape, the leaf edge curled downward, the stem, the stem, the stem and the fruit became grayish brown, and the eggplant was seriously damaged after the bud stage. Can't bloom. Most of the young fruit is yellowish in the umbilicus after falling flowers. As the fruit grows, it gradually turns dark brown, the peel is cracked, and the seeds are bare.
Control method:
1 Remove the weeds in the field, clean the fields, and clear the litter in time after harvesting the vegetables to eliminate the insect source.
2 Chemical control, starting from the end of May, focus on the inspection of the side of the house, the dam and the mountain side of the field to find the center of the hazard, should be sprayed in a timely manner, focus on the treatment, every 10-15 days from late June to August Spray once, for 3-4 times in a row, the main focus of spraying is the upper part of the plant, especially the back of the young leaves and the tender stems, flowers and young fruits can be selected with 1000 times of dicofol; killing 800 times liquid spray; have good results.
5. Melon is mainly harmful to cucumber, melon, loofah, bitter gourd and other melon crops. It is particularly harmful to melon, and the larvae harm leaves, tops and smashed melons, and the leaves are seriously damaged. Occurrence characteristics: The melon wild carp occurs 6 generations a year, and the old larvae and cockroaches overwinter in the dead branches and leaves. Generally, they begin to see in May, and begin to harm at the end of May. The amount of occurrence in the three months from July to September is large at the end of October. Along the larvae can be seen on melon, cucumber and loofah, the eggs are mostly produced on the back of the leaves, and the scattered or several grains are produced together. The larvae of the 3rd instar larvae sew the leaves to conceal and hide in them. In severe cases, The leaves can be eaten light, leaving only veins. The larva not only eats the young fruit and flowers of the melon, but also invades the melon. The larva is lively. After a little shock, the silk is drooping and the other is transferred. After the larva is matured, it will be white and sputum in the victim, or it will be phlegm in the topsoil.
Control method:
1 The prevention and control of melon wild scorpion should be applied at the peak of hatching of larvae. You can choose to spray 1000 times of dimethoate or trichlorfon, killing or killing 4000 times liquid spray.
2 manually remove the damaged leaf and eliminate the larvae in the leaf;
3 After harvesting the melon crops, it is necessary to collect and burn the dead vines and leaves in time to eliminate the insect source.
From: China Agriculture Network
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