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Occurrence and Control of Panax notoginseng Leaf Rot
Symptoms This disease can harm all aboveground organs except the roots. The most typical symptom is the formation of black spindle-shaped lesions at the top of the petiole. When temperatures are high, the lesions rapidly encircle the petiole and quickly spread to the base of the leaflets, forming light black water-soaked lesions on the leaves with irregular edges. The diseased part of the petiole quickly softens, causing the upper leaflets to droop (commonly known as "twisted-down plate"). On the diseased areas, pale yellow powdery masses tinged with pink are often visible, which are the fruiting bodies of the pathogen. When attacking the middle of the leaf blade, it forms black irregular lesions with irregular edges,
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Is copper hydroxide effective for treating rice bacterial leaf streak?
How effective is copper hydroxide for treating rice bacterial leaf streak? How many applications are needed? Please answer objectively. Thank you for your question. The answer is as follows: Copper hydroxide can control rice bacterial leaf streak, bacterial leaf blight, rice blast, sheath blight and rice false smut, etc. Before or at the early stage of disease onset, spray with a 53.8% dry suspension concentrate at 900-1100 times dilution, with 2 consecutive applications.
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Green copper emulsion is highly effective against rice bacterial leaf streak
In an average epidemic year, the control efficacy reaches 85-91%, which is 10-15 percentage points higher than that of Japanese-made chlorothalonil. Method of use: in an average epidemic year, spraying twice is sufficient. The first spray is applied at stages 2-4 of young panicle differentiation in rice; 7 days after treatment the disease tends to stabilize, new acute lesions decrease significantly, and the original lesions stop developing after turning yellow. The second spray is applied 10 days later, using 100 mL of 12% green copper emulsion per mu each time, diluted 500-600 times for spraying. After 20 days, the rice leaf color turns noticeably greener, and the newly emerged flag leaf and the second leaf from the top have no
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Physiological leaf roll in potatoes
[Disease diagnosis] The symptoms of physiological leaf roll and viral leaf roll share certain similarities. The main manifestation is the upward curling of the leaflets. Usually the lower leaves of the plant, or all the leaves of the whole plant, become brittle and curl upward into a tube shape. In some cases only the leaf margins curl slightly upward; in others the curling is severe, forming a spoon shape or tube shape. In severe cases, the leaves become thicker, brittle and hard, and darker and more intense in color, giving a feeling of a messy, clustered clump. The characteristic of physiological leaf roll is that the leaf rolling shown by affected plants is relatively uniform. [Cause] There are several causes of physiological leaf roll: for example, excessive one-sided application of nitrogen fertilizer,
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What are the control methods for leaf spot disease in geraniums?
Control of leaf spot disease in geraniums: 1. For small-scale plantings, remove diseased leaves by hand and burn them in a centralized manner. 2. Improve the growing environment. In areas with severe outbreaks, practice crop rotation, avoid planting too densely so as to allow good ventilation and light penetration, and drain standing water promptly. 3. During the disease period, spray with 100 to 150 times diluted Bordeaux mixture or 80% Captan wettable powder at 500 times dilution; you can also spray a mixture of 50% Thiophanate-methyl at 1000 times dilution and 80% Captan at 500 times dilution, or spray a 45% Chlorothalonil and carbendazim mixed suspension concentrate at 1000 times dilution, which gives better results than a single fungicide.
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What are the control methods for Geranium leaf spot disease?
Symptoms mainly affect the leaves. Initially, small water-soaked spots appear, which later become circular, 2-3 mm in diameter, slightly sunken in the center, with a small brown center and a yellow spreading margin around it. Old lesions can reach 6-10 mm in diameter and, restricted by leaf veins, become irregular in shape, dark brown, with concentric rings, and bear a sparse pale black mold layer on the surface. When there are many lesions on a leaf, they can merge with each other, often causing the leaf to turn black, shrivel and die. The disease conditions mainly occur on older, weakened tissue, so it is most often seen first on the lower old leaves. Rainy weather, excessive
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Variety Characteristics and Planting Methods of the Red-Leaf Cherry Blossom
The red-leaf cherry blossom is a variety of the magnificent cherry blossom. After many years of selective breeding abroad, its traits have become stable. The flowers are very large, pale red, double-petaled, and have long stalks. In Shandong, it blooms in April and May, with the flowers opening before the leaves or at the same time as the leaves, and the blooms are large and showy. After the leaves emerge, they are dark red in early spring, bright red from May to July, gradually turning deep purple in the hot and rainy season, and the leaves are large and thick, turning orange-red when frost arrives in late autumn. The red-leaf cherry blossom is best propagated by grafting and cuttings. Grafting can be done between March and April or between July and August
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Japanese maple (Acer palmatum) is an excellent colorful-leaf tree species.
Scientific name: Acer palmatum Thunb. English name: Japanese Maple. Family: Aceraceae. Japanese maple (Acer palmatum) is a plant of the genus Acer in the family Aceraceae, also known as chicken-claw maple, maple tree, and green maple. Morphological characteristics: deciduous small tree, up to 8 m tall. Crown umbrella-shaped and hemispherical, bark smooth, young branches green and slender. Leaves opposite, palmately 7-lobed, occasionally 5-9.
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How to control broadleaf weeds in potato fields?
(1) Crop rotation: Rotation reduces the density of associated weeds, changes the dominant weed community in the field, and lowers the weed population in the field. (2) Plowing and turning: After the soil is plowed and turned multiple times, perennial weeds such as Ixeris denticulata are buried underground, causing the weeds to gradually decrease or decline in vigor, thereby inhibiting their growth and achieving the purpose of weed control. (3) Inter-row cultivation and hilling: This measure not only controls weeds but also has effects such as deep loosening and water storage and moisture conservation. For example, for open-field potatoes, inter-row cultivation is generally carried out the first time when the seedlings are about 10 cm tall,
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Red-leaf cherry blossom is a colorful-leaf landscape tree species with high ornamental value.
Red-leaf cherry blossom: a variety of the magnificent cherry blossom (Prunus serrulata), a deciduous small tree with large pink double flowers. Its leaves are purple-red for three seasons: in early spring the emerging leaves are deep red, from May to July they are bright red, then the older leaves gradually turn deep purple, and in late autumn when frost comes the leaves turn orange-red. The cherry blossom is a famous flowering tree; the red-leaf cherry blossom offers both flowers and foliage to admire, making it a precious ornamental colorful-leaf tree species for landscape gardens and urban greening, and also the most promising tree species to recommend first.
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