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Symptom Identification and Control Methods for Black Locust Trunk Rot
Symptoms: The disease affects the branches and trunks of young trees to large trees, causing branch dieback or death of the entire tree. In large trees, it mainly occurs at the base of the trunk, and in a few cases at the forks of upper branches and tips. When the base of a large tree is affected, there are no obvious external symptoms; when the bark is peeled back, the interior has already discolored and rotted, with a foul odor, and irregular brown to dark brown patches appear on the surface of the xylem. The lesions continuously expand, encircling the trunk for 1 full turn, causing the branches and trunk above the lesion to die, and the leaves immediately turn yellow and wilt. When the branch tips or the main stem of young trees are affected, the diseased tissue shows water-soaked rot, producing obvious canker lesions that are slightly sunken with purplish-brown edges
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Comprehensive Control Methods for Damping-Off Disease in Spruce Seedlings Grown in Greenhouse Tunnels
In high-cold mountain areas, greenhouse tunnel seedling cultivation is usually adopted to shorten the cultivation period of spruce seedlings and enable earlier out-planting. The special environment of the greenhouse tunnel creates conditions for the breeding and spread of various pathogenic bacteria and organisms that cause damping-off in newly sown spruce seedlings, and improper control can lead to failure of seedling cultivation. To control damping-off in newly sown spruce seedlings in greenhouse tunnels, the policy of "prevention first, comprehensive control" must be adhered to. 1 Damping-off symptoms The symptoms of damping-off mainly manifest in 4 types: (1) After sowing but before emergence, seeds and ungerminated sprouts rot and die in the soil,
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How to prevent and control pests and diseases of oleander? A detailed guide to practical methods
1. After aphids are found, spray the plants with a 40% dichlorvos emulsion at 800 times dilution, or with water in which cigarette butts have been soaked; when there are only a few, they can also be brushed off. For other control methods, refer to the pest and disease control section for Chinese rose and scarlet sage. 2. Scale insects damage the branches and leaves. Control method: spray the plants with Jiesha at 2000 times dilution. For other control methods, refer to pest and disease control for crape myrtle. 3. Black spot disease This disease occurs easily under high temperature and high humidity and damages the leaves. After it appears, spray with 50% carbendazim at 500 times dilution or thiophanate-methyl at 600 times dilution. For other control methods
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Occurrence and Control Methods of Oleander Aphid Infestation
Morphological characteristics: The aphid belongs to the order Homoptera, family Aphididae. Wingless parthenogenetic female: body length 2.3 mm, width 1.2 mm, oval in shape, yellow in color, with distinct markings on the eighth abdominal segment. The body surface has obvious reticulate patterns. The median frontal tubercle is raised, with a flat top; the antennae have imbricate sculpturing and are 2/3 of the body length. The cornicles are long and tubular; the cauda is tongue-shaped, constricted in the middle, bearing 11-14 long curved hairs. Winged parthenogenetic female: body length 2.1 mm, width 1.0 mm, elongate-oval; head and thorax black; antennae 3/4 of the body length. Abdominal segments 2-4 have small marginal tubercles; cornicles are long and cylindrical.
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Cultivation Techniques and Daily Care Methods for Oleander
Oleander (Nerium oleander), also known as willow-leaf peach or half-year red. Belongs to the family Apocynaceae, genus Nerium. It gets its name because its flowers resemble peaches and its leaves resemble bamboo. The flower colors are gorgeous - either pink, like peach blossoms, full and vivid; or pure white, bright and clean as snow, sparkling and striking. It has been appreciated by people since ancient times. Cultivated everywhere, it is an excellent flowering shrub that blooms in summer and autumn and can resist pollution. (I) Morphological Characteristics and Varieties. Evergreen large shrub, plant height can reach 4 m to 5 m, crown spreading, branches upright and smooth, clumping
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Symptoms and Control Methods of Euonymus japonicus Scab
Pathogen: fungus of the genus Colletotrichum, class Coelomycetes, order Melanconiales, subdivision Deuteromycotina. Symptoms: Euonymus japonicus scab mainly damages leaves and branches. On the leaf surface, circular or nearly oval spots 1 mm to 2 mm in diameter first appear, and later the diseased tissue dries up and falls off, forming holes. When new shoots are infected, dark brown circular or oval slightly raised lesions appear on the surface, like scabs, with a grayish-white center. Later, 1 to 2 small black dots, namely acervuli, form in the center of the lesions. In severe cases, leaves drop off, ultimately causing the branches
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Methods and Technical Key Points for Raising Black Locust Seedlings from Seed
Black locust is a pioneer tree species for afforestation on barren hills, with characteristics such as tolerance to poor soil, tolerance to drought, fast growth, and wide uses. 1. Nursery site selection and land preparation The seedling-raising site should be selected as level ground with good drainage, deep and fertile neutral sandy loam soil, and irrigation conditions. Vegetable plots must absolutely not be chosen, and continuous cropping is even less suitable. After the seedling-raising site is selected, plow it in autumn to a depth of about 30 cm. In early spring, harrow it fine and level, and apply 5000 kg of decomposed barnyard manure per mu. During land preparation, poisonous soil made from phoxim emulsifiable concentrate should be applied to control underground pests.
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What are the control methods for the Comstock mealybug on golden-leaf privet?
In Hengshui, Hebei, golden-leaf privet once suffered damage from the Comstock mealybug, which at the time caused the death of large patches of golden-leaf privet. Through research and control efforts in recent years, good results have been achieved. The control experience is summarized as follows: The Comstock mealybug (Pseudococcus comstocki) is also known as the mulberry mealybug. Its eggs are generally laid between the leaf stalk and the branch, oval in shape, light orange-yellow, with dozens of them gathered into a mass, forming a white flocculent egg sac. It produces 3 generations per year. The peak occurrence period of the first-generation nymphs is mid-to-late May, the second generation peaks in mid-to-late July, and the third generation peaks from late August
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What are the propagation methods for golden privet?
Easy to grow and requiring only minimal care, golden privet (Ligustrum × vicaryi) is generally propagated by cuttings, with a rooting rate of nearly 100% and a survival rate of up to 95%. It has a well-developed root system and strong absorbing capacity, so it needs no fertilizing when grown in ordinary garden soil. It sprouts suckers readily and tolerates pruning well, so it is very easy to train into a ball shape during cultivation. Its branches and leaves are dense, making it suitable for growing as a low hedge; pruning it twice a year is enough to achieve an excellent foliage display.
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What are the common pests of golden privet (Ligustrum vicaryi)? A detailed guide to control methods
Golden privet (Ligustrum vicaryi) is a semi-evergreen small shrub of the genus Ligustrum in the family Oleaceae. Because its young shoots are golden yellow and it tolerates pruning and drought, it is often combined with red-flowered Loropetalum (Loropetalum chinense var. rubrum), azaleas (Rhododendron) and Chinese juniper (Juniperus chinensis) to decorate flower beds and green belts. High-density planting often makes pest problems more severe, causing new shoots to grow slowly or not sprout at all, weakening the plants and even killing them. The common and most damaging pests of golden privet are: the citrus mealybug (Planococcus citri), the privet leaf-mining flea beetle, and the yellow-ringed silk-fringed pyralid moth. 1 Citrus mealybug adults and nymphs rest on the branches and leaves of golden privet and suck plant sap with their piercing-sucking mouthparts,
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