Occurrence and control of main diseases, insects and rodents in lily

Lily, also known as night lily, mountain lily, Pengpeng flower, etc., is a kind of medicinal, edible and ornamental plant with a large market demand. Lily is also a traditional export specialty of our country, which is planted all over the country. However, with the expansion of lily planting area, diseases, insect pests and rodent pests are becoming more and more serious, which has become the main factor restricting the stable and high yield of lily. In this paper, the occurrence and control methods of main diseases, insects and rodents of lily are introduced as follows:

1 main diseases and their control

1.1 there are many kinds of lily diseases, but most of them are fungal diseases such as Botrytis cinerea and Fusarium wilt. In addition, viral and bacterial diseases are also serious in some areas.

1.1.1 Botrytis cinerea, also known as lily leaf blight, mainly harms the aboveground parts. After the disease, the leaves first produced small brown spots, and then gradually expanded into a circle. When the humidity was high, the gray mildew layer could be seen on the disease spots on the back of leaves, and the disease spots were easy to spread and aggregate, resulting in brown rot of the whole leaves. The flowers show small brown spots after being infected with the disease. On the other hand, the infected stem showed long brown spots, plant atrophy and folded. The pathogen of the disease is Botrytis cinerea, and the primary infection source is mainly the sclerotia overwintering with the remains of the diseased plant in the soil. When the temperature rises to more than 10 ℃ in spring, the sclerotia produces conidia, which is transmitted to the plant by Rain Water and others, resulting in the primary infection. In general, the temperature is suitable and the humidity is high from May to June, which is conducive to the spread of the disease.

1.1.2 Fusarium wilt can harm all organs of plants. The damaged plants were dwarfed, the leaves wilted and withered after yellowing, the underground bulbs produced brown rot, and the scales often fell off from the stem disk. The disease was caused by Fusarium oxysporum. The mycelium overwintered in the bulb or in the soil with the remains of the diseased plant. The temperature of the following spring began to occur at about 12 ℃, and the peak period was from mid-April to mid-May.

1.1.3 Blight, also known as lily foot rot, can harm all organs of the whole plant. Flowers, leaves infected with waterlogged brown spots, and then gradually expanded, there is a white mildew layer above. The disease spot on the stem can continue to expand and grow into strips and rot, causing the plant to die. The initial infection of the corm was waterlogged brown spot, and then gradually rotted. The disease was caused by Phytophthora blight. Chlamydospores or oospores overwintered in the soil with the remnants of the diseased plants, and mycelium infection occurred in the following spring when conditions were suitable. The general temperature is 22: 26 ℃ and the rainy and humid conditions are beneficial to the occurrence and spread of the disease.

1.1.4 soft rot is a bacterial disease, which mainly harms the bulbs during storage. After the bulb was infected, the irregular waterlogged spot appeared at first, and then expanded, which made the whole bulb rot. The pathogen of soft rot is Erwinia carrot, which can be transmitted by seed bulb and soil.

1.1.5 virus diseases mainly include mosaic disease, cluster disease, ring spot disease and so on, which can cause yellowing of leaves, dwarfing and deformity of plants and necrotic spots on stems. These diseases are mainly transmitted by bulbs or insects (mainly aphids).

1.2 Prevention and control measures

1.2.1 most of the pathogens harmful to lilies by the combination of disease-free varieties and soil disinfection can overwinter with the remains of diseased plants in the soil (gray mold, Fusarium wilt, blight, etc.), and the bulbs can also carry bacteria (soft rot, Fusarium wilt, etc.). Therefore, broad-spectrum fungicides such as carbendazim can be used to disinfect soil and seed balls and sow seeds, or virus-free vaccines (to control virus diseases) can be cultivated by tissue culture. This is the basic link of disease prevention.

1.2.2 the fungal diseases of lily caused by crop rotation and timely cleaning are mostly soil-borne diseases, and continuous cropping provides conditions for the accumulation of germs in the soil; therefore, it is best to rotate with different crops, and the diseased plots should be stopped for 2 or 3 years. In addition, clean up the remains of the diseased plant in time, burn them centrally or use them as biogas, so as to reduce the base number of bacteria.

1.2.3 applying sufficient basal fertilizer, grasping planting density and improving plant resistance are fertilizer-loving plants. Adequate basal fertilizer should be applied, and attention should be paid to the reasonable combination of nitrogen, phosphorus, potassium and organic fertilizer, which can make the plant grow healthily and improve the ability of disease resistance. Over-dense planting will lead to lack of light, poor field air circulation and increased humidity, which is conducive to the occurrence of diseases.

1.2.4 Biological control it is reported that microbial agents such as Bacillus and Streptomyces have good effects on Fusarium wilt and Botrytis cinerea, and the control effect can last for many years.

1.2.5 at the initial stage of chemical control, 50% Sukeling, 70% methyl topiramate (control of Botrytis cinerea), 20% Shiduqing (control of virus disease) and 40% ethylphosphine aluminum (prevention and control of blight) were sprayed, which can effectively inhibit the further development of the disease. Before entering the cellar or cold storage, the bulbs were treated with more than 50% carbendazim and then dried to prevent the occurrence of soft rot during storage.

2 main insect pests and their control

2.1 aphids can occur for more than 10 generations a year, and the damage peak is from April to May. Adults and nymphs cluster on stems and leaves to suck sap, making leaves curly, plants short, and infecting virus diseases at the same time, causing greater harm.

Control methods: 2000 times of 20% methamphetamine EC or 2.5% of 2000 times of kungfu EC, or 1000 times of 80% dichlorvos can be sprayed on aphids of plants, which can play a better control effect and reduce the occurrence of virus disease accordingly.

2.2 grub grubs can directly bite off the roots and stems of seedlings, resulting in dead seedlings and eating bulbs.

Prevention and cure method: it can be applied in poisonous soil mixed with methyl isosaliphate EC before planting. In the case of damage in the growing period, methyl isosinophos can be used to irrigate the roots. Grubs can be caught artificially during autumn ploughing to reduce the population number of overwintering insects.

2.3 ground tiger larvae can bite off the stem of the seedling near the ground, resulting in the death of the whole plant, and can also harm the bulb in the soil.

Control method: remove the weeds on the edge of the field in time. Preventing adults from spawning is the key to the control of ground tigers. Can also be the ground tiger likes to eat gray vegetables, alfalfa and so on stacked to trap and kill or supplemented with chemical poisoning. It can also be sprayed with 20% fenvalerate, 90% trichlorfon, or root irrigation with methamidophos.

2.4 mites concentrate on the young parts of the plant with adult mites and young mites, which do harm to the juice, which makes the leaves stiff and yellowish brown, and can lead to dead seedlings in serious cases.

Control method: crop rotation. Timely removal of weeds at the edge of the field can reduce the occurrence of mites. In addition, propargite and isocarbophos can be used for spray control.

(3) main rodent damage

Zokor and mole are the main rodents that harm lilies and can bite underground bulbs. Prevention and control methods: you can use rat traps (devices) to capture manually or mix the food that rodents like to eat with rodent poison and put it at the mouth of the cave to attract and kill.