Control techniques of diseases and insect pests of hollow cabbage

Ipomoea aquatica was formerly known as water spinach, also known as rattan cabbage, spinach, arenaria, urn cabbage, empty cauliflower, bamboo leaf cabbage, etc., like high temperature and humid environment, suitable for moist soil, like sufficient light, not strict requirements for soil conditions, like fertilizer and water, white trumpet-shaped flowers whose stem center is empty, so it is called "hollow cabbage". It is widely cultivated as vegetables in rural areas of southern China. Next, let's take a look at the pest control techniques of asparagus.

Brown spot of Chinese cabbage

[harm symptoms] the disease spot on the leaf is nearly round, sometimes limited by the large leaf vein, and becomes semicircular or irregular, and the diameter of the disease spot can reach 5-10 mm. The disease spot is brown, dark brown or reddish brown, which varies from variety to breed, usually with a dark edge and a light middle color. A small spot is embedded in the middle of most plaques, the center is light, the edge is dark, and several plaques can be fused into larger patches. After the disease spot develops along the main vein, the leaf can be twisted. Crack in the middle of the lesion when it is dry. When damp, the spot is black and moldy on both sides.

[induced pathogen] the pathogen goes out of season in the disease residue, and the disease residue produces conidia, which spreads with wind and rain and causes primary infection. After the disease of the plant, conidia were produced on the disease spot, which continued to spread and infect. Re-infection can occur many times in a growing season.

[agricultural control] ① reasonable fertilizer and water: reasonable fertilization according to the characteristics of varieties, increase the application of rotten organic fertilizer, pay attention to the combination of nitrogen, phosphorus and potassium, prevent vegetable plants from being de-fertilized, reasonable watering, do not over-irrigation, timely drainage after rain, reduce humidity. ② removed the old leaves: the seriously diseased fields were rotated for more than 2 years, and the diseased old leaves at the bottom of the vegetable plant were removed in time. ③ cleaning the garden in time: after harvest, remove the sick and residual body in time, turn the soil deeply, and root out the weeds in the field.

[chemical control] at the initial stage of the disease, you can choose to spray 1200-1500 times of 25% trimethoprim wettable powder, 1000-1300 times of 50% prohydantoin wettable powder, 1000 times of 70% mancozeb wettable powder, 65% mancozeb 500-600 times, 70% thiophanate wettable powder or 75% chlorothalonil wettable powder. Spray once at intervals of 7-10 days and use medicine 3-4 times.

White rust of Chinese cabbage

[harmful symptoms] White rust of hollow cabbage mainly harms the leaves. At the onset, the leaves appear yellowish green to yellow spots on the front, then turn brown, the disease spots are larger, and the back of the leaves are protuberant sore spots, close to round or oval or irregular shape. When the leaves were seriously damaged, the disease spots were dense, the diseased leaves were deformed, the leaves fell off, the stem swelled and deformed, and the diameter increased by 1 to 2 times.

[condition of onset] the temperature of 20-35 degrees is the most likely to develop the disease.

[chemical control] 35% metalaxyl seed mixture with 0.3% seed weight. At the initial stage of the disease, 58% metalaxyl manganese zinc wettable powder was sprayed 500 times, 40% triethyl aluminum phosphate (frost plague) 250 times 300 times, once every 10 days, for 2 times in a row.

[agricultural control] selection of disease-free seeds, 2-3 years of rotation, good disease control effect, pay attention to field sewage discharge and ventilation, reasonable arrangement of density.

Anthracnose of hollow cabbage

[harmful symptoms] Colletotrichum gloeosporioides mainly harms leaves and stems, and seedlings are easy to die. The leaf is infected, the disease spot is nearly round, dark brown, the spot is slightly wheeled, there are dense small black spots, the disease spot is enlarged and fused, the leaf turns yellow and dry, and the disease spot on the stem is nearly oval, slightly sunken inward.

[disease conditions] High temperature and rainy, excessive application of nitrogen fertilizer, overgrowth, overlapping stems and leaves without light, easy to occur.

[control methods] spraying 70% carbendazim wettable powder 800 × 1000 times or 50% thiram powder 600 times, 40% polysulfide suspension 500 times, 77% can kill 600 times, 10% difenoconazole water dispersible granules (Shigao) 50 × 75 g / mu, 80% Bordeaux liquid wettable liquid (essential) 300 × 500 times, 25% bromazonil wettable powder (carbendazim) 2000 × 2500 times, once every 10 days, continuously for 3 times. Stop taking medicine 5 days before harvest.

Ring spot of hollow cabbage

[harmful symptoms] the main harmful leaves were small brown spots on the leaves at first, round, oval or irregular shape after expansion, reddish brown or light brown, large disease spots with obvious concentric rims, and small black spots on the later round spots.

[disease conditions] when it is rainy and the growth is closed, the disease is easy to occur.

[chemical control] at the initial stage of the disease, spray 1 Vera 0.5 Val 160 200 Bordeaux solution or 45% Dysenamine aqueous solution 1000 times, or 75% Chlorothalonil wettable powder 600 times 700 times, or 58% Metalaxyl manganese zinc wettable powder 500x solution, 50% imidamide wettable powder (Polydo) 35g / mu, 70% propionium zinc wettable powder (Antaisheng) 150g / mu, 10% difenoconazole water dispersible granules (Shigao) 3550g / mu, 710g / mu For 2 or 3 times in a row.

[agricultural control] remove withered leaves and diseased bodies from the ground in winter, and combine with C to turn deeply to accelerate the decay of the remains. 1-2-year rotation can be carried out.

Spinach leaf curler

[damage characteristics] most of the newly hatched larvae ate the mesophyll and showed small white spots in the heart leaves and tender leaf sheaths of rice seedlings, as well as in the tips of rolled leaves damaged by old buds and rice thrips. The 2nd instar larvae gnawed on the mesophyll and left the skin, showing a short white strip, spinning longitudinally curled leaf tip 1.5-5 cm. The 3rd instar larvae gnawed on the mesophyll with white spots, and the bracts of the longitudinally rolled leaf insects were 10-15 cm long. The 4th instar larvae overate the leaves and eat meat and leave the skin. One larva can eat 6-10 rice leaves.

[agricultural control] ① uses bunches or heaps of grass to trap overwintering mature larvae. ② killed the overwintering larvae of fallen leaves, cracks or buildings in autumn and winter, killed the newly hatched larvae in summer, and removed the injured leaves if necessary. ③ placed black light to trap and kill adults.

[chemical control] attention should be paid to the prevention and control of the third generation and the fourth generation in Shandong and Jiangsu and Zhejiang provinces. 1000 times of oil or 1500 times of double-acting phosphorus EC, 1000 times of crystal trichlorfon, 1000 times of imidophos, 1500 times of Regent and 1000 times of phoxim were sprayed before rolling leaves at the end of the second instar.

Aphids of Chinese cabbage

[damage characteristics] aphids have strong fecundity and rapid development. The Guangdong area can reproduce 30 to 40 generations a year. Warm and dry is beneficial to the reproduction of aphids. Aphids live on the back of leaves, pedicels or tender stems as adults and nymphs, sucking pepper juice and secreting honeydew. The injured leaves turned yellow and curled. The tender stems and pedicels were damaged with curved deformities, which affected flowering and fruiting, inhibited plant growth, and even withered and died. Aphids can also spread a variety of viral diseases, aggravating the occurrence of viral diseases. Aphids have a strong tendency to yellow and orange, but have a negative tendency to silver gray.

[agricultural control] ① clean the countryside: remove weeds in the field and its vicinity and reduce the source of insects. ② silver gray film mulching cultivation: make use of aphids' negative tendency to silver gray to achieve the purpose of avoiding aphids and preventing diseases. ③ yellow trapping insects: taking advantage of aphids' tendency to yellow, yellow trapping boards were set up in the field to trap and kill winged aphids. The size of the yellow plate is 1 m × 0.2 m, and the yellow part is coated with engine oil and inserted between the rows of chili peppers, 60 cm higher than the plant, 30 pieces per mu.

[chemical control] in the initial stage, use 1000 times of 10% high-efficiency Dagongchen wettable powder, 1000 times of aldicarb, 1000 times of 10% Leibao emulsion, or 3000 times of 10% paracetamol, or 50.5% Nongdile 1500 times, or 47% Lesbon emulsion 1000 times, etc., alternately, every 7 days and 10 days, 2 times in a row.

Pieris spinosa L.

[damage characteristics] Pieris rapae nibbled on the back of the leaves at the early age, and the residual epidermis showed small concave spots, and the leaves became holes or lacked after the 3rd instar. In severe cases, only veins and petioles remain. At the same time, a large amount of feces were discharged, which polluted the leaves and hearts of cabbage, which made the quality of vegetables worse, and the insect injury provided an invasive way for soft rot bacteria, which led to the occurrence of soft rot in vegetable plants and accelerated the death of the whole plant.

[agricultural control] ① clean the countryside: remove the residual plants and leaves in the field in time after harvest and burn them centrally in order to reduce the density of insect population. ② artificial capture: it is easy to capture larvae, pupae and adults, and adults can be caught by net. ③ protects and utilizes natural enemy insects: this method can not only prevent insects but also protect the environment and reduce pesticide pollution.

[chemical control] use 10 billion live spores / g Bacillus thuringiensis wettable agent, spray 50-60 kg water with 100300g / mu, or spray 10 billion live spores / gram Pseudomonas aeruginosa powder 1000 times, or dilute it into 1000-1500 times liquid spray with 10 billion live spores / Bacillus thuringiensis wettable powder. One of the above chemicals shall be sprayed in the initial period of the pest, once in 7-10 days, and can be sprayed 2-3 times continuously. The above biological pesticides can also kill other butterfly moth pests on vegetables. However, it should be noted that the above biological pesticides cannot be used in vegetable fields near the mulberry garden, nor can they be mixed with chemical fungicides.

Plutella xylostella

[morphological characteristics] the adult body is 6-7 mm long, the wingspan is 12-16 mm, the front and rear wings are slender, the cilium is very long, the front and rear wing edges show yellow-white three-degree zigzag wavy lines, the two wings close together, the hair on the front wing margin is long and warped like a chicken tail, the antennae are filiform, brown with white lines, and protrude forward when still. The female is larger than the male, with a cylindrical end of the abdomen and a conical end of the abdomen of the male, with a slightly open grip. The egg is oval, slightly flattened, about 0.5 mm long and 0.3 mm wide, yellowish and glossy at birth, and the eggshell surface is smooth. The newly hatched larvae are dark brown and then turn green. The last instar larvae are 10-12 mm long and spindle-shaped with sparse, long and black setae on the body. The head is yellowish brown, and there are light brown hairless dots on the forechest dorsal plate to form two "U" patterns. The hip foot extends backward beyond the end of the abdomen, and the ventral toe hook has a single missing ring.

[agricultural control] rational distribution, try to avoid large-scale annual continuous cropping of cross hat vegetables, so as not to repeat the source of insects, strengthen the management of seedling fields and control them in time. After harvest, the residual plants and fallen leaves should be treated in time to eliminate a large number of insect sources.

[physical control] Plutella xylostella has phototaxis, and black light can be placed to trap and kill Plutella xylostella in order to reduce the source of insects.

[biological control] bacterial insecticides, such as BT emulsion, can kill Plutella xylostella larvae.

[chemical control] Diflubenzuron 700x, 25% Kuaishaling 2000 times, 24% Wanling 1000 times, 5% carbazem 2000 times for prevention and treatment. Pay attention to alternate use or mixed use to slow down the emergence of drug resistance.

Red spider of Chinese cabbage

[damage characteristics] overwintering with adults, nymphs and eggs under the leaves of the host, in soil crevices or on nearby weeds. Temperature and humidity are closely related to the growth and decline of the number of red spiders, especially the temperature has the greatest influence. When the temperature is about 28 ℃ and the humidity is 35-55%, it is most favorable for the occurrence of red spiders, but when the temperature is higher than 34 ℃, the red spiders stop reproducing and the reproduction is restrained. Red spiders have parthenogenetic habits, and unfertilized eggs hatch into males. When the eggs hatched, the egg shell cracked and the larvae climbed out, settled on the leaves first, and then molted into the first instar stage. The activities of larvae and nymphs were less in the early stage, while in the later stage, the nymphs were active and gluttonous, and had the habit of tending to tender. the larvae generally climbed upward from the lower part of the plant, causing damage and moving upward.

[control method] the red spider must be sprayed in the early stage, that is, at the initial stage of the occurrence of the red spider spot piece, the red spider should be sprayed immediately. The available agents are 73% carotene EC 3000 times, 20% synergistic acarine 2500-3000 times.

Liriomyza huidobrensis

[damage characteristics] the larvae sneak under the epidermis of the host leaves, zigzag through, and feed on green tissue, resulting in irregular gray-and-white linear tunnels. When the damage was serious, almost all the leaf tissue was damaged, and the leaves were covered with decay channels, especially the leaves at the base of the plant suffered the most, even withered and died. The larvae can also eat young pods and pedicels. Adults can also suck plant sap to make the sucked place a small white spot.

[control methods] timely irrigation with ①, elimination of weeds, elimination of overwintering and oversummer insect sources, and reduction of insect population. ② should control the peak period of adults and spray in time to control adults and prevent them from spawning. Adults mainly lay eggs on the back of the leaves and should be sprayed on the back of the leaves. Or spraying to control larvae at the beginning of the harm, the larvae should be sprayed for 2 or 3 times continuously, and the pesticides can be used 1000 times of 40% dimethoate EC, 1000 times of 2000 times of omethoate EC, 800 times of 50% dichlorvos EC, 1500 times of 50% dibromophos EC and 1 000 times of 40% diazinon EC.