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Pest and Disease Control Methods and Technical Key Points for Bonsai
Diseases on branches and trunks: These manifest as rot of the phloem and cambium of branches and trunks, stem rot and cankers on branches and trunks, surface rot of branches and trunks, decay of the inner wood, and spots on twigs. In such cases, Bordeaux mixture should usually be sprayed, followed by lime sulfur mixture, and the decayed parts should be scraped off. Foliar diseases: Foliar diseases usually show symptoms such as yellow-brown or black spots, leaf curling, wilting, and early leaf drop, and may be chlorosis, leaf spot disease, sooty mold, powdery mildew, etc. For leaf spot disease, remove the diseased leaves and spray Bordeaux mixture; for chlorosis, use 0.1-0
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Pests Harming Orchids and Their Control Methods (Part One)
Pests that harm orchids include scale insects, aphids, spider mites, thrips, whiteflies, leaf miners, snails and slugs, nematodes, caterpillars, cockroaches, ants, and others. 1. Scale insects Scale insects are one of the most common pests harming orchids. There are many species, mainly parasitizing the stems and leaves of orchids, and they can also be seen on the petioles and the membranous sheaths at the base of pseudobulbs, appearing as a white powdery substance. They feed by sucking plant sap with their piercing-sucking mouthparts. In mild infestations, they cause the affected organs to turn yellow and age, affecting the growth of the orchid plant; in severe cases, they cover the leaf surface in patches, consuming nutrients and affecting the orchid's
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Detailed Methods for Controlling Pests of Tropical Orchids (Part Two)
5. Whiteflies. Whiteflies are pests of the family Aleyrodidae in the order Homoptera. The insects are relatively small, with white powdery waxy material covering the whole body, and they usually cluster on orchid plants. They are prone to occur when ventilation in the orchid greenhouse is poor. They often damage the new shoots, tender leaves and flower buds of orchids. When causing damage, they insert their piercing-sucking mouthparts from the underside of the leaves, sucking the sap from the plant tissues, causing the leaves to turn yellow and withered, and they often excrete large amounts of honeydew at the wound sites, causing sooty mold and the occurrence of brown rot, and even causing the death of the entire plant. Because whiteflies have strong reproductive capacity, they can reproduce 9~10 generations within a year in a greenhouse, and can form a huge
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Magnolia Propagation and Cultivation Methods and Pest and Disease Control Techniques
I. Morphological characteristics: A deciduous tree, about 25m tall. Leaves alternate, relatively large, broadly obovate to obovate, entire. Flowers solitary at the top of branches, white bell-shaped, fragrant. The flowering period varies by region, such as Kunming from November to December, Guangzhou from February to March, Hangzhou in March. Cultivated varieties are short with dense branches, and flowers are large and abundant. Seedling plants are tall with straight trunks, branches slightly sparse, flowers sparse and foliage luxuriant, but with strong adaptability and rapid growth. Propagated by sowing, grafting, layering and cuttings. Growth habits: Warm and humid, with a shaded side environment, slightly shade-tolerant, mature trees prefer light, suitable for growing in acidic or slightly
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Cultivation Methods and Key Technical Points for Plum Bonsai
Plums are deeply loved for their brilliant and varied forms and colors and their rich, fragrant fruit aroma. Plum bonsai is popular because it offers both flowers and fruit. Selection of rootstock and varieties: choose dwarf rootstocks with strong compatibility with the grafted variety, and prefer varieties with bright fruit color, high yield, and slightly weak growth vigor. Plums have very rich variety diversity. Traditional excellent varieties in China include "Furen Li, Jiaqing Li, Xieli Li, Hongxiang Li, Yuhuang Li, Mi Li, Wuyue Li," and others. Currently, domestic
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Causes and Control Methods of Magnolia Chlorosis
Also known as chlorosis, it is a common disease of magnolia, and occurs more commonly in areas with alkaline soil. In the northern regions of our country, the disease is relatively severe. Symptoms: The diseased plant first shows symptoms on the young tender leaves at the top of the shoots. The mesophyll tissue of the diseased leaves turns yellow or pale yellow, while the veins remain green; as the disease progresses, the entire leaf turns yellow to yellow-white, and the leaf margins become gray-brown or brown and necrotic. The condition gradually worsens, the plant grows weak, and eventually dies. Causes: Magnolia chlorosis is a non-
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Causes and Control Methods of Azalea Chlorosis
Azalea chlorosis is a non-infectious disease and also a common disease in azalea cultivation. After the plant is affected, the leaves become thinner, lose their green color, and turn pale, so this disease is also called chlorosis. The lack of green is obvious in new leaves. When the color of new shoot leaves becomes lighter and the leaf mesophyll turns yellow while the veins remain green, it is generally diagnosed as iron deficiency symptoms. This phenomenon mostly occurs in alkaline soil and in areas where slightly alkaline water is used to water flowers. After symptoms appear on the leaves, photosynthesis cannot proceed normally. In mild cases, it affects the growth and development of the plant
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What are the control methods for azalea leaf spot?
1. Symptoms: Small reddish-brown spots first appear on diseased leaves, gradually expanding into nearly circular spots, or restricted by leaf veins into polygonal lesions, 1-5 mm in diameter, dark brown; sometimes grayish-white in the center with indistinct edges. The spots are darker on the upper surface and lighter on the lower surface of the leaf, and lesions at the leaf margin may merge with one another; when humid, grayish-black mold spots mostly form on the surface of the diseased areas. 2. Pathogen: The pathogen of azalea leaf spot is Cercospora rhododendri Ferraris, belonging to the order Hyphomycetales, class Hyphomycetes. The grayish-black mold spots on the lesions are
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How to prevent and treat root rot in rhododendrons? These methods you need to master
Root rot is a serious threat to rhododendrons. Although its incidence rate is not high, the mortality rate after infection is very high, so the prevention and treatment of root rot must be taken seriously in the cultivation and management of rhododendrons. Root rot is a soil-borne disease caused by Fusarium fungi, mostly occurring at the root and stem parts of rhododendrons, because these parts are often moist with insufficient sunlight, and the Deuteromycetes Fusarium fungi are highly active there. Once they invade the cortex, rot soon follows, with water-soaked brown spots and soft rot appearing on the roots, followed by decay and peeling of the bark, the xylem turning dark brown
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Identification and Control Methods of Rhododendron Flower Rot
Symptoms Rhododendron flower rot only harms the flowers, causing the flowering period to shorten, flowers to droop, and early withering and dropping. After the petals are infected, the diseased parts lose their luster, become water-soaked, soft and discolored, and finally turn brown, rot and blacken; when humid, a gray mold layer grows on the surface, affecting ornamental value. Pathogen and disease pattern This disease is caused by a fungus of the class Hyphomycetes, subphylum Deuteromycotina. The pathogen forms sclerotia on rotten flowers, and the sclerotia fall into the soil with the spent flowers to overwinter. In the flowering period of the following year, conidia are produced, spread by wind and rain or air currents, and when the flowers sprout
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