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What medicine is effective for controlling cotton red leaf disease?
Control the top and promote the bottom to enhance the stress resistance of cotton plants. First, for cotton with vigorous growth, apply the plant growth retardant succinic acid or mepiquat chloride to control excessive growth; use 2-3 grams of mepiquat chloride or 8-12 milliliters of mepiquat chloride per mu, mixed with 50 kg of water for spraying. Second, for cotton fields with compacted soil, cultivate and aerate in time to enhance permeability. Third, for cotton fields in low-lying areas, pay attention to clearing ditches and beds at any time to promote cotton roots to grow downward. Fourth, for cotton fields using plastic film mulching cultivation, remove the plastic film immediately so that cotton roots develop deeper. Apply more potassium fertilizer to improve fertilization efficiency. For soil
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Symptom Identification and Control Methods for Cotton Angular Leaf Spot
Symptoms: This disease not only damages cotton seedlings but also harms the stems, leaves, and developing bolls of mature plants. When seedlings are infected, the cotyledons develop water-soaked irregular or round lesions that are dark brown; in severe cases, the cotyledons wither and drop off. When true leaves are infected, small dark green spots first appear on the underside of the leaves, then expand into oil-soaked lesions; on the upper surface of the leaves, the lesions are mostly angular, and sometimes the lesions extend along the veins in irregular streaks, causing the leaves to turn yellow and drop off. When stems are infected, water-soaked main lesions appear, then expand and turn black or rot, the diseased area becomes sunken, and the pathogen bends to one side. When the terminal bud is infected, it forms a "rotten top," causing the entire plant to die.
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Detailed Explanation of Control Methods for Licorice Leaf Spot Disease
① The pathogen is a type of imperfect fungus (Cercospora astragali), belonging to the subdivision Deuteromycotina → Moniliales → Cercospora fungus. It damages leaves; affected leaves produce circular or irregular lesions, with the center of the lesion grayish-brown and the edges brown, and grayish-black mold-like growth on both the front and back of the lesions. Fruiting bodies grow on both sides of the leaf, but mainly on the upper surface; the stroma consists of only a few brown cells; conidiophores are born in bundles of 6 to 12, pale brown, with the apex lighter in color and narrower, unbranched, having 0 to 5 geniculate nodes, with the apex nearly truncate, spore scars prominent, and 1 to 7 septa; conidia are whip-shaped to obclavate, colorless and transparent, straight to curved, with the base truncate to nearly truncate, the apex slightly blunt, and 3 to 10 septa.
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Symptom Identification and Control Methods for Azalea Leaf Spot Disease
Azalea leaf spot disease, also called brown spot disease, is a common and frequently occurring leaf spot disease of azaleas. After infection, black spots form on the leaves, which gradually dry up and fall off until the plant dies. The disease mainly harms azalea leaves and is caused by infection with the fungus Cercospora rhododendri. The pathogen first appears as several small brown dots, and as these dots continue to expand, the lesions connect with each other to form patches, producing grayish-brown mold hyphae. The affected leaves begin at the petiole, turn from green to brownish-yellow, and drop early. In severe cases, it affects the growth and development and ornamental value of azaleas. The pathogen overwinters on leaves or diseased plants,
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Symptoms and Control Methods of Leaf Blight in Hybrid Magnolia
The main symptoms occur on the leaves, and in severe cases can spread to the petioles and flower buds. The lesions mostly occur at the leaf margins. In the early stage, they are chlorotic yellow spots, water-soaked in appearance. Numerous lesions merge into patches, expanding outward in a fan shape, with dark brown edges and grayish-yellow centers, which can cause early defoliation. In humid environments, black-gray granular bodies appear on the fallen leaves. Causes of the disease: This disease is a fungal disease; the pathogen survives in leaf buds and on diseased plant residues, spreads via air currents, and can directly infect and damage through the stomata of leaves that are weak in growth or physiologically injured. Injured plants and environmental conditions with high wind speed
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Methods and Techniques for Leaf Pruning and Shaping of Bonsai
Leaf pruning can make bonsai trees that normally produce leaves once a year sprout and leaf out multiple times. Leaf pruning can make bonsai send out green leaves again, restoring their vibrant and lively appearance, making them more beautiful and more ornamental. About 1 month before leaf pruning, fertilizer and water management should be strengthened to prompt new buds to sprout quickly after leaf pruning and grow into tender leaves. The timing of leaf pruning varies depending on the tree species and the viewing period. However, except that leaves cannot be pruned during natural spring budding, leaf pruning can be done at other times, and generally spring and autumn are the best times for leaf pruning. The number of leaf prunings can also be determined according to the tree species and the ornamental
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Detailed Explanation of the Occurrence Patterns and Control Techniques of the Jujube Leafroller
The jujube leafroller belongs to the family Tortricidae, order Lepidoptera. The jujube leafroller damages the leaves, flowers, and fruits of jujube trees, seriously affecting the yield and quality of jujube. The jujube leafroller has a single feeding habit, only damaging jujube trees and wild sour jujube, with larvae feeding on jujube leaves, flowers, and fruits. It produces 3 generations per year, overwintering as pupae in cocoons under old cracked bark and in clods of soil around the trunk. In the following year, eclosion begins in late March, with the peak of eclosion in early April; adults are strongly phototactic, and eggs are laid singly on smooth twigs and leaves. The first-generation larvae hatch in early May (before the Beginning of Summer)
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Red-leaf winter peach is a rare premium variety among late-maturing peaches.
In the northern Henan region of Henan, red-leaf winter peach shows pink buds on March 25, begins flowering on April 1, with pink flowers, 5 petals, a flower diameter of 3.5-4 cm, and a flowering period of 7-10 days. Flowers and leaves grow simultaneously; the pink peach blossoms and purplish-red peach leaves form the only red scenic line worth viewing in spring. As the seasons and temperatures change, the purplish-red peach leaves gradually turn copper-green from the base upward, but the new shoots and new leaves at the top remain purplish-red, forming on the same branch lower leaves that are copper-green
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Jujube leaf roller
Also called the jujube leaf-rolling worm, its larvae bite and eat jujube leaves, jujube flowers and fruit, and can also bore into fruit clinging to leaves, causing fruit drop and greatly affecting yield. This insect overwinters as a pupa in cracks in the bark of the main trunk of the jujube tree, and from mid-March to late April the overwintering pupae begin to emerge. Occurrence periods of larvae of each generation: first-generation larvae, mid-April to late June, bite and eat young buds and tender leaves; second-generation larvae, mid-June to early August, damage jujube flowers, leaves and young fruit; third-generation larvae, late July to mid-October, especially damage leaves, and then bore into fruit. Adults hide during the day
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Symptom Identification and Control Methods of Garlic Leaf Blight
Leaf blight is a major disease of green garlic and, in severe cases, causes the entire leaf to die off, affecting yield. I. Symptom identification This disease mainly damages leaves and flower stalks. When leaves are infected, it usually starts from the leaf tip and gradually develops toward the leaf base, spreading from the bottom upward. At first, pale white small round spots appear, which later expand into oval or irregular grayish-white or grayish-brown lesions, and black mold-like growth develops on the diseased parts; in severe cases, the entire leaf dies off. When flower stalks are infected, they tend to break at the diseased part, and finally many small black grains are scattered on the lesions.
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