Control techniques of Diseases and insect pests in eggplant

Eggplant was first produced in India and was introduced into China in the 4th-5th century AD. The cultivated area of eggplant in China is about 3 million mu. The main diseases are eggplant cotton blight, eggplant brown stripe, sudden fall, blight and so on. The main pests are red spiders and Liriomyza huidobrensis. Let's take a look at eggplant pest control techniques.

Eggplant cotton blight

[damage symptoms] eggplant cotton blight is also known as "rotten eggplant", "egg drop" and so on. In addition to harm eggplant, but also harm tomatoes, cucumbers, potatoes and so on. On eggplant, it is mainly harmful to fruits, stems and leaves, and flower organs can also be damaged. The fruit initially appeared waterlogged round or oval brown spots, rapidly expanded and sunken, often the whole fruit rotted, white loose mildew when wet, the internal pulp became black and rotten, easy to detach from the calyx. Water-immersed dark brown spots were produced on the twigs, which overflowed and withered and withered, while the seedlings were susceptible to the disease.

[disease condition] the pathogen overwintered mainly on the diseased remains in the soil, and in the second year it could directly infect the stem or root of the seedling, or splashed on the fruit near the ground by Rain Water to cause fruit disease. The spores on the disease spot are re-infected by wind, rain and watering. General 7-August, continuous rain, muggy weather, low-lying nest wind, poor drainage, weak growth when the disease is serious.

[control methods] resistant varieties were selected for ①, such as Beijing nine-leaf eggplant, six-leaf eggplant, Tianjin Dawei, Liaoqie 3, Fengyan 1, Jinan Zaoxiaochang eggplant and so on. ② agricultural control: avoid continuous cropping with Solanaceae crops. Select sandy loam with high dryness and good drainage, high border or small high ridge planting or wide ridge close planting, apply sufficient base fertilizer, remove diseased old leaves in time and concentrate treatment, can not be used to compost fertilizer, harvest and clean up the diseased fruit in time after rain. ③ chemical control: spray once before the onset of the disease or before the onset of the rainy season. After the disease, remove the diseased fruit and leaves, spray once in about 7 days, 2-3 times in a row. The medicament has 1 ∶ 1 ∶ 160Bordeaux solution, 50% methyl topiramate 1000 times solution, 50% carbendan 500 times solution. At the peak of the disease, 72% of DuPont Kelu wettable powder, 58% metalaxyl manganese zinc wettable powder and 64% poisonous alum wettable powder were sprayed.

Brown streak of eggplant (also known as dry rot)

[damage symptoms] when the seedlings were injured, similar fusiform waterlogged spots were formed at the base of the stem near the ground, and then turned dark brown, sunken and contracted. When the conditions are suitable, the disease spot expands around the stem and the seedlings are quenched. Leaf damage, first from the bottom of the leaf disease, gradually developed to the upper, began to produce watery brown, gray or light brown in the middle, many small black spots in the central whorl. The disease spot is easy to crack when dry, and perforation is easy to be formed in cloudy and rainy days. Stem damage, disease spot is uncertain, sometimes water-stained fusiform disease spot, dark brown edge, gray-white in the middle, many small black spots, disease spot gradually sunken dry rot, and connected into a longer necrotic area. The fruit suffered the most seriously, at the beginning of the disease, there were yellowish-brown spots on the fruit surface, slightly sunken, round or oval, expanding rapidly, the fruit was semi-soft rotten, and in the later stage, there were many small black spots, and finally the diseased fruit rotted off or dried on the branches.

[disease condition] eggplant brown streak is a fungal disease, which only infects eggplant. The pathogen overwinters on the remains of the soil surface disease, and it can also winter on the seeds. Seed-borne bacteria is not only the main cause of seedling quenching and blight, but also the way of long-distance transmission of pathogens. The field spread mainly by Rain Water, insects and field operations. The suitable temperature for the disease is 28-30 ℃, and the relative humidity is more than 85%. The disease is serious in North China from July to August with high temperature and rainy, or high temperature and high humidity. It is also easy to cause disease when the cultivation density is too high. In addition, continuous cropping, poor drainage, heavy soil, too much nitrogen fertilizer and early spring eggplant planting too late, the disease is also serious.

[control methods] ① seed treatment: soak the seeds with 40% formalin 100x solution for 15 minutes, remove them and rinse them with clean water, or soak the seeds with 1000 times mercury solution for 10 minutes. ② agricultural control: rotation with other vegetables for 2-3 years. Carry on the seedbed disinfection, the five generation mixture is 8-10 grams per square meter, or 50% carbendazim is 10 grams, add fine soil 20 grams to mix well, before sowing, sprinkle on the border surface, after sowing, cover with 2 gamma 3 herbal soil. Strengthen cultivation management, that is, N, P, K fertilizers should be used together, sufficient base fertilizer should be applied, diseased plants and leaves should be found, and diseased fruits should be removed in time. ③ medicament control: at the initial stage of the disease, 75% chlorothalonil wettable powder, 50% methyl topiramate, 65% mancozeb and 70% mancozeb were used. Spray every 7-10 days for 2-3 times.

Cataplexy

[damage symptoms] sudden collapse, also known as neck jam, is mainly infected at the seedling stage. Seeds can occur after germination and before they are unearthed. The disease is rotten seed or bud before it is unearthed. After being unearthed to 2 true leaves, it mainly occurs at the base of the stem. The base of the stem near the ground of the diseased seedling showed water-stained spots, then yellowed and constricted into a linear shape, and when the cotyledons did not wilt, the seedlings fell on the ground, that is, when the seedlings fell, the leaves were still bright green, so it was called quenching disease. When the environment is wet, a layer of white woolly hyphae grows on the diseased seedlings and the nearby soil.

[disease conditions] the pathogen overwintered in the soil with the remains of the diseased plant, or saprophytic in humus. Bacteria can survive in the soil for 2-3 years, and there are more bacteria in the soil with high content of organic matter. Germs are spread by Rain Water or the flow of water in the soil. When the temperature is 15-20 ℃, the reproduction is faster. Therefore, when raising seedlings in spring or winter, encounter rainy or snowy weather, or the greenhouse has poor heat preservation, poor ventilation, too much watering, often low seedling bed temperature, high humidity, and serious sudden collapse disease.

[control methods] selection of disease-resistant varieties for ①: according to local consumption habits and temperature conditions, low-temperature-tolerant or early-maturing varieties were selected, such as Jinan Xiaochang eggplant, 94-1 early-long eggplant low temperature-tolerant varieties, Liaoqie 1, Liaoqie 4 cold-tolerant varieties, etc. ② soil disinfection: 2-3 weeks before sowing, mix 5 grams of methyl topiramate and 50 times fine soil per square meter and sprinkle them in the seedbed, or mix 7-8 grams of 65% Dysen zinc and 40% pentachloronitrobenzene powder, or 50% carbendazim 8-10 grams plus 15 kg fine soil to make medicine soil, pour through the bottom water before sowing, after the water seeps, sprinkle 1X on the bed surface. Then cover the remaining 2 thumb and 3 medicinal soil on the seed, about 1 cm thick, so that the seed is sandwiched between the medicinal soil. ③ agricultural prevention and control: the seedbed should choose fertile land with high dry terrain and good drainage. In the greenhouse, the garden soil that has not grown eggplant fruit vegetables for many years should be selected as bed soil. Strengthen the ventilation and humidity of the seedling raising place before sowing, and the bed soil should be fully exposed to the sun. Watering as little as possible after emergence, in order to improve the ground temperature, and timely ventilation and light transmission. The greenhouse was covered with no dripping film to improve the light conditions in order to facilitate photosynthesis and improve the disease resistance of seedlings. It can also spray 800 times Lvfeng 95 plant growth regulator to enhance the resistance of seedlings.

[chemical control] after the disease of the seedlings, the leaves were sprayed with 75% chlorothalonil wettable powder, 64% chlorothalonil M8 wettable powder, 1000 times dimethazone solution, or 500x thiram solution, or 800x carbendazim solution. When the disease occurs, the root is irrigated with potassium permanganate solution of 800-1000 times, and then the leaf surface is cleaned.

Blight disease

[damage symptoms] Rhizoctonia solani mostly occurred in the middle and later stage of seedling rearing. After the seedlings were infected, the oval brown disease spot appeared at the base of the stem, then it became thinner and constricted, and the stem and leaves wilted and died. The aboveground part wilted during the day, recovered at night, and withered after repeated several times. There are wheel lines or brown mildew in the disease. When large seedlings or adult plants are damaged, the base of the stem is ulcerated, and the aboveground parts turn yellow and wilt, resulting in death.

[incidence conditions] Rhizoctonia solani is a fungal disease, which overwinters on soil residues or humus and is transmitted by Rain Water, running water, soil and fertilizer. The suitable temperature for the development of the pathogen is 17-18 ℃, and high humidity is beneficial to the disease. The seedling bed is warm and humid, the ventilation is poor, and the seedlings are easy to grow.

The control method is similar to the control method of sudden drop disease, and the key point is to strengthen the management of seedling bed, combined with chemical control. ① strengthens nursery bed management: the method is the same as cataplexy. ② soil disinfection: using Wudai mixture to disinfect soil can prevent not only blight disease but also quenching disease. The method is the same as quenching disease. ③ chemical control: spray 75% chlorothalonil wettable powder, 64% disinfectant alum, or 70% mancozeb wettable powder every 7-10 days, 2-3 times in succession.

Red spider

[damage symptoms] often gathered on the back of the leaves to prick and suck juice with stabbing mouthparts, the damaged leaves began to show small white spots, turned green into yellow and white, and in severe cases, the leaves of the whole plant dried up and turned red like fire, and the leaves fell off. When the fruit is damaged, the pericarp becomes thicker and affects the quality.

[occurrence regularity] 10-20 generations a year, overwintering with adults lurking in weeds and soil cracks. The following spring, first breed in weeds or overwintering places, and then transfer to eggplant or other vegetables. It begins to invade the lower old leaves, and then spreads upward. North China suffered heavy damage from the end of May to the beginning of July. High temperatures and droughts tend to occur in large numbers.

[control methods] ① cleaning fields: clean up the weeds, dead branches and fallen leaves around the eggplant plot, clean up the residual branches and leaves after pulling seedlings, so as to reduce the source of insects. ② chemical control: at the beginning of the occurrence, use 1000 times of 20% dicofol, 1000-1500 times of 25% manganese wettable powder, 1500-2000 times of 1500-2000 times of ciprofen wettable powder or 78% of paracetamol EC 2000 times, spray once every 7 days, spray 2-3 times continuously, focus on the back of leaves, and can be used alternately.

Liriomyza huidobrensis

[damage symptoms] both adults and larvae can be harmful, and larvae are the main damage leaves. The adults prick and suck the juice, and the larvae sneak into the leaves to produce irregular serpentine white insect channels, which affect photosynthesis and fall off when the leaves are serious.

[occurrence regularity] Liriomyza huidobrensis propagates quickly and has a short generation interval. It generally breeds one generation in 15-30 days in summer and one generation in 40-60 days in winter. It can happen annually in the sanctuary. After the larvae lived in the leaves for 4-7 days, the old larvae bit through the epidermis outside the leaves or pupated on the soil surface.

[control methods] Agricultural control of ①: strict quarantine to prevent the insect from spreading, rotation, intercropping and intercropping with vegetables of other families. Remove damaged old leaves and withered yellow leaves in time and destroy them centrally. Centralized elimination at the initial stage of occurrence. When a small number of leaves are found to be damaged in the field, the larvae can be pinched to death one by one, and then sprayed to control, the effect is very good. Using fly-killing paper to trap and kill adults, because the adults have yellowing, the yellow board can be used to apply oil to trap and kill. ② medicament control: you can use 1.8% Efortin EC 3000-4000 times, or 90% Wanling wettable powder 2500-3000 times, or 98% Batan powder 1500-2000 times, or 50% fly maggot powder 2000 times spray. Spray once every 7-10 days, 2-3 times in succession. Pay attention to alternating use of drugs. The control of adults should be sprayed in the morning or evening, and the control of larvae should be carried out in the low instar stage, that is, when the length of most insect pests is less than 2 cm. Protected areas can be fumigated with dichlorvos.