Pests and diseases have always been the main influencing factors in loquat cultivation. In this paper, we analyze the diseases and insect pests encountered in the process of loquat cultivation, and propose effective control methods to provide a reference for the control of loquat diseases and insect pests. Some of the diseases and pests of loquat and their control methods are introduced as follows:
Flax pigmented spot disease mainly harms seedlings, resulting in the death of a large number of seedlings, commonly known as "seedling plague". At the beginning of the disease, black and purple spots appear on the leaves, turning into off-white spots, then into large spots, and the leaves wither. The disease is a mycosis, the infection temperature is 10 to 15 ° C, more than 20 ° C will be significantly reduced. The rainy season is the peak season of the rainy season.
Control method: drainage and weed control. Cut off diseased leaves in time to remove burned and severely ill seedlings. Before epidemics and initial episodes, spray 2 to 3 times 70% methyl tolbuzin 800 to 1000 times solution or 1500 times solution of phenyl selenide.
Leaf spot disease, including spotted, spot and gray spot, mainly damages the leaves, causes early defoliation and weakens tree viability. Gray spot disease can also harm the fruit, causing the fruit to rot. The disease is a fungal disease that mostly invades from the pores of young leaves or the pores of fruits and wounds. It can easily occur in warm and humid environments and can be infected multiple times a year.
Control methods: improve drainage, prune and clean gardens, improve environmental conditions, increase tree vitality and improve disease resistance. In spring, summer, autumn and at the beginning of new shoots, spray 70% methyl tolbuzin 800-1000 times solution or 50% carbendazim 800-1000 times solution, again every 10-15 days.
Anthrax mainly harms ripe fruit and causes fruit rot. First, light brown water stain spots appear on the fruit, and then the surface of the fruit sinks, and small black dots appear on the spots, which are arranged in concentric circles and rapidly expanded. The disease is a fungal disease that is transmitted by wind, rain and insects.
Prevention and control methods: strengthen orchard fertilizer, water and soil management, enhance tree vitality, improve disease resistance. Strengthen garden cleaning to reduce the source of disease. In orchards that were seriously ill last year, when the fruit changed color, spray 0.5% to 0.6% Bordeaux solution or 70% methyl tolbuzin solution 500 to 600 times solution 1 to 2 times.
Sunburn can occur on branches and fruits. At the beginning of the sunburn on the stem, the bark withers and atrophes, cracks intensify, and the diseased area expands into scorched masses, reaching the xylem, which looks like fire. After the fruit is sunburned, the sun flesh of the fruit is charred, and the diseased part turns black-brown and dries. Plaques have completely lost their food value and often lead to the occurrence of anthrax. In dense fog and high temperature weather, fruits during the discoloration period are prone to occur, and fruits exposed to direct sunlight are also prone to occur. The bark of branches exposed to the scorching sun for long periods of time burns easily.
Prevention and control methods: breed anti-Japanese sunning varieties, cultivate a reasonable canopy, so that the branches are not exposed to direct sunlight. Strengthen soil improvement and fertility management so that loquat roots are deep and leafy. Bagging of fruit during color change, or spraying water in the afternoon in case of foggy and hot temperatures in the morning.
Leaf blight usually makes loquat very weak and loses its ability to be strong. The cause has not yet been determined. The tip of the disease turns yellow at first, then expands downwards, and finally turns brown and scorches. The diseased leaves are about 1 cm long, the tips of the leaves are burned to death, and the diseased spots are 2-3 cm in diameter. Diseased leaves are stiffer or remain only petioles, or they fall off earlier, resulting in small leaves on the tree. It usually occurs on the young leaves that were originally drawn. Symptoms begin when young leaves grow to 2 cm. Summer leaf disease is the most severe, followed by spring leaves and autumn leaves.
Prevention and control method: select disease-resistant varieties. Strengthen soil improvement and fertilizer management to enhance tree vitality and disease resistance.
Fruit splitting disease. During the rapid fruit expansion phase, if heavy rain falls suddenly after a long drought, it will cause the pulp cells to expand rapidly, and the outer skin will rupture and rupture. Cracking fruit not only affects the appearance of the fruit, but also easily causes infection and pest destruction of a variety of pathogens (mainly anthrax). The disease is more common in overgrown trees and thin-skinned varieties and is severe south of 25 degrees north latitude.
Control method: select varieties that are not easy to split fruit. During the period of rapid expansion of young fruits, topdressing outside the roots, such as spraying 0.2% urea, borax or potassium dihydrogen phosphate, works well. During the discoloration of the fruit, the spraying of 0.1% ethylene and bagging is obvious.
Purple spot disease. Purple-red rust spots appear on the fruit, which only affect the appearance and hardly affect the quality of the flesh. Symptoms of the disease appear suddenly at a later stage of fruit ripening. During the harvest period, there are often sunny days and strong sunshine.
Prevention and control method: select disease-resistant varieties. The fruit is bagged.
Yellow caterpillar It is the main pest of loquat, mainly harming young leaves and seriously weakening the vitality of trees. The first generation of larvae can also harm the fruit, eat more peel, affect the appearance, and even lose its edible value. During the day, the larvae lurk on the back of the old leaves or on the trunk of the tree, and sooner or later they will climb to the surface of the young leaves and become injured.
Control method: artificial killing, eliminate the winter and the recesses of the branches on the main vein of the leaf, eliminate the larvae on the larvae. At the beginning of each new shoot, if harmful is found, spray 40% Lego 1000x solution, or 80% dichlorvos 800-1000x solution, or 20% chrysanthemum (rapid killing) 4000-5000x solution. During the fruit harvest period, no pesticides are allowed.
Pear small heartworms mainly harm the phloem tissue of fruits and branches. Early damaged fruits usually die halfway; later injured fruits contain too much feces to be eaten; larvae on branches burrow into the epidermis and bite into the cortex; and callus on the graft interface of seedlings is often bitten and bored to death. The first larvae are milky white and then turn reddish. The heads of mature larvae are dark brown. Usually, the hazard begins in early April to mid-October.
Prevention method: Protect the wound. Trap and kill adults. The insects sprayed the larvae in March and again after 5-7 days.
Boat-shaped caterpillars are also known as loquat boat moths, loquat moths and tail worms. The first larvae are purple-red, clustered, with well-developed silk threads, which are harmful to the mesophyll. The wounded leaves were like gauze. It has many insect mouths and plenty of food. It often eats the whole leaf. The larvae are frightened and die due to rotation.
Prevention and control methods: In autumn and winter (more in October), they often go to orchards and remove clusters of harmful leaves. If the hazard has been eliminated, 50% dichlorvos 800x solution or 20% chrysanthemum (rapid killing D) 5000x solution or 90% dichlorvos 1000x solution can be used.
The hazards of beetles to loquat mainly include mulberry nails, star nails, cloudy nails and red-necked nails. The control method refers to the control of chestnut beetles
Leopard wood moth leopard. Wood moths are also known as coffee wood moths. The larvae swallow branches, and the injured branches break or die in the wind. A generation occurs within a year, with the larvae overwintering in the worm passages of the branches. Adults are phototropic and lay their eggs on the new shoots or axillaries of new shoots. The newly hatched larvae invade from the axillary bud at the tip of the bud, and then the injured shoot turns to the neighboring bud. The larvae are 30–40 mm long, pale red, and have a yellowish-brown head.
Harmful 0.5-5 cm thick branches of the pulp, worms from bottom to top, worm passage round, bite a excretory hole not far away, fecal particles oblong, pointed and slippery, not easily broken, and obviously recognizable with beetles fertilizer. Prevention method: Winter combined with pruning to prune insect branches. Regular inspections from March to April and June to July found that wilted new shoots were cut off and burned in time. Lights seduce adults. When the larvae invade deeply, use 80% dimethods to enter the wormhole 10-30 times and apply yellow mud on the outside.