Common Diseases of Lotus and Their Solutions

1. Rot disease

The most common disease of lotus is rot, because it is easy to have some problems when soaked in water for a long time. So be careful not to soak the leaves in water, when the soil is barren, the incidence of rot will be very high, at this time should be appropriate fertilization, and then spray some carbendazim control.

2. Brown spot

During the rainy season, the leaves of lotus leaves may have brown spots, so be sure to clean up the sick leaves immediately so as not to infect other leaves. If the disease is serious, you can spray carbendazim or Dyson zinc solution.

The above is the introduction of potted lotus planting methods, diseases and insect pests and solutions, I hope the above content can help you better plant potted lotus, want to know more, please pay attention to the four Seasons Plant Network!

Common diseases and insect pests of lotus and their control methods

The lotus is graceful. The flowers are big and colorful. The fragrance is striking. The resolute character of the lotus is highly praised by people for its unstained character. However, the lotus is vulnerable to a variety of diseases and insect pests during its growth, which affects the ornamental value. Common diseases and insect pests are: 1. After the onset of the disease, there are round disease spots on the leaves, light brown in the center, dark brown around, often with concentric rings, and dark green mildew on them. The disease is caused by fungal infection. Most of them occur from July to September. Under the condition of warm, humid climate and continuous planting for many years, the disease occurred seriously, the cultivation and management was poor, the plant growth was weak, and the disease was also serious. Prevention and control methods: ① thoroughly remove diseased leaves in winter; ② disease area, before planting basin (tank) soil or pond soil mixed with a small amount of lime for soil disinfection; ③ to strengthen cultivation management, do not apply too much nitrogen fertilizer, pay attention to ventilation and light; ④ from near the onset period, every 7-10 days to spray 65% zinc 600 times solution. Continuous spraying for 3 times and 4 times can prevent the occurrence and spread of the disease. At the initial stage of the onset of ⑤, 50% carbendazim or 70% topiramate was sprayed 800 times. two。 After the black spot was infected by the pathogen, there were nearly round or irregular disease spots on the leaves, 6mm-15mm in diameter, brown, with wheel lines and black mildew. In severe cases, the disease spots often converge and the leaves die. The disease is more serious than brown spot in Northeast and North China. Except that the pathogen and symptoms are different from brown spot. Its occurrence regularity, onset time and control methods are basically the same as that of brown spot. 3. Rot is a fungal disease, which begins from the lotus root node, and the leaves turn yellow. Curl withered and died, and finally the stem and lotus root nodes rotted one after another. Prevention and treatment methods: ① pond soil or basin soil properly mixed with a small amount of lime, while soaking lotus root in human lime milk for 10 minutes for disinfection; spraying 70% topiramate 800x solution at the initial stage of the onset of ②. 4. Aphid nymph and adult aphids often gather in new leaves, rolled leaves, standing leaves and flower storage to suck sap. When the number of insect population is long, the young leaves change color and curl, and the flowers become zaki-shaped or can not open, affecting the ornamental effect. This insect has a strong fecundity. It can reproduce about 20 generations every year, and it can do harm from May to September, especially in late and mid-autumn. Prevention and cure method: ① sprays 60x tobacco lime water or neutral detergent 300x-40x liquid; when ② occurs in large quantities, spray 40% dimethoate emulsion 1500 times. 5. The moth is commonly known as' pocket moth'.' The main damage to lotus is big coir moth and tea coir moth. The larvae eat the leaves and bite the lotus leaves into holes when they occur in large numbers, which has a great impact on the appearance and flowering. The generation of the insect occurs every year and varies from region to region. Generation I occurs in Jiangsu, Zhejiang, Hubei and other places every year, which can do harm from the lotus leaf just coming out of the water until the lotus canopy is mature. Prevention and treatment: when a small amount of ① occurs. The protective capsule was removed manually, and when a large number of ② occurred, it was in the larval early hatching stage or larval stage. Spray 1500 phoxim emulsion or fish rattan powder 1500 times (plus a small amount of neutral detergent) e 6. Spodoptera litura is commonly known as "itchy spicy". The lotus flowers are harmed by yellow diamondback moth, green diamondback moth, brown diamondback moth and so on. All the larvae were harmful to the leaves. The yellow-green larva is yellow-green and the body length is 25mm. The head is small and light brown. There is a purple-brown dumbbell-shaped stripe on the back, and the larva is 25mm-28mm, yellowish green, with four superior protuberances from the middle foot to the 8th ventral segment with yellow bristles on the superior process. The young larvae only feed on mesophyll. Residual veins, eat the leaves into a network. When the larvae grow up, they bite the leaves into gaps, leaving only the petiole and the main vein. Control methods: in winter and spring, ① dug up the cocoons in the topsoil around the pond (Spodoptera litura, Plutella xylostella) and cut off the overwintering cocoons on nearby branches (Plutella xylostella); ② found the newly hatched larvae and removed the insect-carrying leaves in time; ③ larvae sent 1500-2000 times emulsion or 50% fenitrothion emulsion 1001 times. 7. Spodoptera litura, also known as Spodoptera litura. The larvae are about 30mm long, with dark brown head and varied colors, such as khaki, dark green, but scattered white dots. Algebra occurs every year, depending on the local temperature. According to local observation, July-October is the most harmful every year. The newly hatched larvae gather leaves to eat mesophyll, leaving epidermis and veins, and the injured leaves are gray and white like screens. It turns yellow after dying. When the larva is slightly larger, it bites the leaf into a gap. When the number of insects is long, the leaves can be eaten incomplete. And can bite buds and flowers. Control methods: ① artificial killing, making use of the habit of adults laying eggs and newly hatched larvae with clustered leaf back, timely removal of egg blocks and insect leaves, centralized treatment; ② young larvae are harmful period, spraying 50% phoxim emulsion 1500 times-2000 times liquid or 50% carbaryl wettable powder 500 times-800 times solution, the control effect is good.

Common diseases and insect pests of lotus

Symptoms of lotus brown spot: the disease is also known as brown streak. The leaf spot is round or nearly round, the size is different, light brown, the edge is dark brown to purplish brown, some appear concentric wheel pattern, the spot surface is dense with small black spots, in severe cases, the disease spot is densely covered and connected into plaques, and the disease mass is locally dry. The pathogen: Cercospora nymplaeacea. = C.enotica., C.nelumbonis Tharp is called Cercospora mellesii, which belongs to the subphylum of semiknowns. Conidiophores scattered or several tufted, unbranched, light olive brown, size 10 ~ 50 × 2.5 ~ 4 microns; conidia long inverted stick to linear, colorless to pale, straight or curved, septum up to more than 10, thin walls, base navel marks obvious, size 25 ~ 125 × 2 ~ 3.5 microns. Transmission route and disease condition: the pathogen overwintered on the diseased body with mycelium and conidia, carried out primary infection and re-infection with conidia, and spread by airflow or wind and rain. The disease is easy to occur in years or seasons with high temperature and heavy rain, especially in years or seasons with frequent storms, and the disease is serious in fields with too dense and poor permeability of continuous cropping or lotus plants. Control methods (1) pay attention to field hygiene, collect disease residues during harvest or growing season, bury or burn them. (2) crop rotation should be carried out in seriously ill areas. (3) reasonable close planting and good management of water and fertilizer. (4) combined with the prevention and treatment of lotus rot disease, spraying medicine in time to cure the disease. Symptoms of black spot disease of lotus: after the onset of the disease, chlorotic macula appeared on the leaves at the initial stage, and the back of the leaves was more obvious. After that, the lesion gradually enlarged, showing irregular brown spots, with a diameter of 5mm to 15mm. The edge sometimes has a yellowish green halo, the disease spot has a concentric pattern, and the upper black mildew layer. In severe cases, except for the veins, the whole leaf is covered with disease spots. After the confluence of disease spots, the leaves are withered and yellow, and the disease area is like a fire. The pathogen of black spot of lotus is Alternaria alternata [Alternaria nelumbii.) Enlows et Rand], which belongs to Trichospora and Trichospora. The spores are club-shaped, with 7-15 horizontal septum and 0-3 vertical septum, with dark color. Route of transmission: the pathogen of black spot of lotus overwintered in the remnant. The disease usually begins after the middle of May. The disease is serious in stormy weather, which will be aggravated by aphids. When nitrogen fertilizer is applied or the water temperature of the lotus tank is too high in summer, the disease will be serious. Prevention and control methods 1. Horticulture control should strengthen cultivation management, remove diseased leaves, and change new soil every year when potted. 2. During the period of drug control, 75% chlorothalonil wettable powder 500 times liquid was sprayed for prevention and treatment. Symptoms of lotus rot: the disease occurs in the whole plant, starts from the seed root, and extends to underground stems, petioles, leaves and pedicels. The underground stem seems asymptomatic at the initial stage, but some of its cross-sectional ducts turn pale brown or brown and gradually expand. Some diseased stems do not change color significantly, but the whole or one side of the stem is longitudinally wrinkled, and the leaves of the diseased stems are light green, and then begin to dry up from the leaf edge, causing the leaves to curl and even die. Pathogen: Fusarium oxysporum specific type [Fusarium bulbigenum Cook et], belonging to half-known subphylum. Small conidia are long oval, colorless, unicellular. Large conidia colorless, crescent-shaped, tip pointed, curved to one side, foot cell obvious, thick chlamydospore. The route of transmission: the mycelium overwintered in the lotus root and in the soil with chlamydospores, the seed lotus root and diseased soil with bacteria became the main source of primary infection, and the seedlings with bacteria were planted in lotus root, the disease occurred in the underground stem and root system at first, then affected the petiole and leaf, and the central diseased plant produced spores to invade from the wound and form re-infection. The disease of deep root varieties was lighter than that of shallow root varieties, and the disease was easily induced by continuous rain, lack of sunshine or frequent storms, poor soil permeability or high acidity in lotus root field, sewage or water temperature higher than 35 ℃. Control methods: 1. Change disease-resistant varieties according to local conditions. 2. The seriously diseased fields should be rotated for 2-3 years. 3. Select disease-free lotus root, and use 50% carbendazim or methyl thiophanate wet powder 800 times solution plus 75% chlorothalonil wettable powder 800 times liquid, spray and stuffy seed, cover plastic film and seal for 24 hours, dry and plant. 4. The lotus root field is ploughed and raked, and 100kg / mu of lime is applied. 5. Strengthen the management of fertilizer and water, apply enough rotten organic fertilizer, topdressing timely and appropriately, make the combination of organic fertilizer and chemical fertilizer, nitrogen fertilizer and phosphorus and potassium fertilizer; according to the different growth stages of lotus root need to manage the water layer, make the depth suitable, adjust the temperature and fertilizer with water, prevent the disease from aggravating due to high water temperature or long-term deep irrigation. 6. Spray 50% carbendazim wettable powder 600 times liquid after timely removal of diseased plants, add 75% chlorothalonil wettable powder 600 times liquid; can also use the above-mentioned mixed fungicide 500 grams per mu mixed with fine soil 25kg 30kg, pile up for 3 hours after 4 hours, sprinkle into the shallow water layer, 2 days later use the mixture 600 times or more than 40%. 400 times of sulfur suspension or 1000 times of 50% Sukeling wettable powder were sprayed on the aboveground petiole. Prodenia litura (Fabricius) Spodoptera litura, also known as Spodoptera litura, Spodoptera litura, belongs to Lepidoptera, Noctuidae. Spodoptera litura, which occurs all over the country, is a gluttonous pest. The main hazard areas are Jiangxi, Hubei, Hunan, Zhejiang, Jiangsu, Anhui and Henan, Hebei, Shandong and other provinces in the Yangtze River basin, while the harm is lighter in the northeast. Spodoptera litura is a polyphagous pest. It is known that there are more than 290 species of plants belonging to 99 families, of which more than 90 species are fond of food. Harmful: the first egg larvae gather to gnaw on the back of the leaves, leaving only the upper epidermis and veins, and the injured leaves are like screens. Disperse the harm after 3 years old, eat the leaves into lacerations, often eat up the leaves, and even bite the young stems. When a large occurrence occurs, the larvae can migrate to the adjacent fields in groups after eating up a field. Morphological characteristics, control methods 1, biological control can use bacterial insecticides, such as domestic B.T emulsion or cyanobacteria No. 6 liquid, usually 500 to 800 times dilution concentration. 2. Chemical control can use phoxim 50% EC 1000 times dilution, deltamethrin 2.5% EC 3000 times, or 21% EC 4000 times. 3. Physiological control of 20% or 25% of chlordiazuron 1 or 3 colloidal suspension 500-10-10, also known as water lily aphid. Distributed in Guangdong, Fujian, Jiangxi, Zhejiang, Jiangsu, Hubei, Hebei and other places. The insect harms lotus, water lily, cattail and so on. Morphological characteristics: the wingless fetal female aphid is oval, hypertrophic, brown-green or dark green, covered with thin frost or white powder, abdominal tube-shaped, tail conical, with 3 pairs of long hairs on it. The winged viviparous female aphid is long ovate, reddish brown, glossy on chest and back, abdominal tube-shaped, wings transparent, and other characteristics are similar to those of wingless type. Life history and habits: the insect occurs for about 20 generations a year. Overwintering with eggs in the armpits of woody ornamental plants such as plum blossom, peach and red leaf plum. In the spring of the following year, after nymph ovalization, parthenogenetic reproduction was done on the first host, and the damage was serious from April to May. In May, winged aphids flew to the second host, such as lotus, water lily, water shield, Euryale and other aquatic plants, causing poor plant growth, shrinking buds, poor flowering quality and even no flowering. The winged aphid flies to the overwintering site in autumn. The control method is to spray 1000 times of 50% aphid pine EC or 2000 times of 50% parathion EC, which is less toxic to fish. For the control of aphids on aquatic plants, special attention should be paid to the selection of pesticides, because many agents are very toxic to fish.