-
What are the control methods for nutrient deficiency diseases in citrus
Zinc deficiency causes mottled leaf disease. Citrus mottled leaf disease is a common disease, with the typical symptom being mottled small leaves. When new leaves begin to turn green, the main veins and lateral veins appear markedly green, while the remaining tissue is light green to yellowish white and glossy. In severe cases, only the area near the main vein or thick lateral veins is green, and the new leaves are narrow and mottled, mostly upright, with short internodes and clustered branches. Mottled disease is caused by zinc deficiency. Many soils are deficient in zinc, such as soils formed from granite, gneiss, and serpentinite, which contain little zinc; acidic sandy soils lose zinc easily; in alkaline soils zinc readily forms insoluble compounds, thus causing zinc deficiency. In addition, soil that is too dry or too wet, low humus content or excessive application of organic matter, which hinders contact between roots and soil, as well as heavy pruning, all make zinc deficiency likely to occur. Foliar fertilization can achieve fairly good results in controlling zinc deficiency. It is advisable to spray 0.2%-0.3% zinc sulfate solution (with an equal amount of lime) once during the tender shoot stage, and spray 2-3 times for severe zinc deficiency.</p><p></p><p>Copper deficiency or boron deficiency causes dieback disease. In the early stage of copper deficiency in citrus, new shoots are long, soft, and slightly curved, the leaves are large and dark, and fruiting is low, so it is easily mistaken for excessive vigor. In severe cases, the tips of the shoots turn tea-brown and die, short weak clustered branches appear, and they dry out and drop early and gum exudes; when the branches mature, the wounds are reddish brown, and parts of the leaves are reddish brown. Citrus has a very small copper requirement, and ordinary spraying of Bordeaux mixture is already sufficient. However, copper deficiency is likely to occur in peat soil, acidic sandy soil, soil with high organic matter content, as well as on abandoned grazing land and abandoned cemetery land; excessive application of barnyard manure and phosphate fertilizer also causes copper deficiency; newly reclaimed citrus orchards that have not been sprayed with Bordeaux mixture or other copper preparations for several years are prone to copper deficiency. Boron deficiency in citrus: the growing points of buds die continuously, forming clustered buds; leaf veins swell, become corky or split; the fruit is small and deformed, with thick hard peel, and brown resin deposits are present in the fruit center and spongy layer. Boron is easily lost from acidic soil, hence boron deficiency. In soil parent materials such as granite, gneiss, and schist, boron content is extremely low; in alkaline soil its solubility is poor, so boron is also deficient. Excessive application of phosphate fertilizer or lime, or soil drought, all affect the availability of boron and the absorption of boron by roots; sour orange has weak boron uptake, so citrus grafted onto sour orange rootstock is generally deficient in boron. For copper deficiency, Bordeaux mixture or other copper fertilizers can be sprayed. To supplement boron, soil application can be used, or 0.05%-0.1% boron fertilizer solution can be sprayed at the bud stage, flowering stage, and small fruit stage.</p>
-
Summary of Experience in Pest and Disease Control for Greenhouse Peach Trees
The main diseases of greenhouse peach trees are scab, shot hole disease, and gummosis; the main pests are aphids, spider mites, and leaf miners. For the control of pests and diseases in greenhouse peach trees, prevention should be the priority, with control during the dormant season as the foundation, to reduce sources of infection. Before and after flowering are the key periods for control
-
Key Technical Points for Early-Spring Pest and Disease Control in Peach Trees
As the early-spring weather gradually turns warm, various peach tree pests and diseases begin to revive, breed and multiply. Early-spring control of peach tree pests and diseases can effectively curb the occurrence and spread of many peach tree diseases and reduce the base population of insect pests. The occurrence and damage of the main peach tree pests and diseases are now presented
-
Methods for Pest and Disease Control in Cherry Trees During Winter Dormancy
Using manual and agricultural methods, clean the orchard, eliminate overwintering sources of pests and diseases, effectively eliminate harmful organisms, and reduce the overwintering population base. 1. Sweep up fallen leaves: Fallen leaves are one of the main overwintering sites for many pests and diseases, such as the pathogens of cherry brown spot disease and black ring rot, which
-
Pear Tree Spring Pest Control Methods and Technical Key Points
Pear tree spring pests and diseases include: pear fruit borer, aphids, red spider mites, pear psylla, stink bugs, leaf-mining mites and black spot disease, etc. Timing and measures of control: from early spring to before flower buds swell, clean the orchard and scrape tree bark. Lay plastic sheeting under the tree, then scrape off the raised and coarse bark on the trunk and large branches, but do not damage the new bark. For the coarse vertical bark at the branch forks, scrape carefully. Collect the scraped bark, larvae, eggs, etc. and bury them deep or burn them. Knock down dead leaves and remaining dried fruit from the tree and remove them from the orchard for destruction, then spray the whole tree once with lime sulfur mixture.
-
Integrated Prevention and Control Methods and Technical Key Points for Prickly Ash Diseases
Prickly ash (scientific name: Zanthoxylum bungeanum Maxim.), also known as hui, dajiao, Qin pepper, Shu pepper, Chuan pepper or mountain pepper. It is a deciduous shrub or small tree of the genus Zanthoxylum in the Rutaceae family, and can be planted as a solitary specimen or used as a protective thorn hedge. Its fruit peel can be used as a seasoning, and aromatic
-
What are the common diseases of Ceylon spinach? Detailed explanation of control methods
Many people may have eaten Ceylon spinach, but few can name it. Judging by its name, it should be a vegetable that looks somewhat like wood ear mushroom. Ceylon spinach not only has edible value, but also has certain ornamental and medicinal value. It has a very good effect of purifying the blood
-
What diseases affect water bamboo? How to prevent and control them
Water bamboo, also known as gaogua, gu sun, gu shou, jiao sun, and gao sun. It is a perennial herbaceous plant with rhizomes in the grass family, genus Zizania. It is divided into double-crop water bamboo and single-crop water bamboo (or divided into one-harvest jiao and two-harvest jiao); double-crop water bamboo (two-harvest jiao) has higher yield and better quality. The ancients
-
Control Methods for the Three Common Diseases of Pinellia
The three common diseases of Pinellia are: tuber rot, viral disease (leaf-curling disease), and damping-off (leaf-scald disease). These three diseases severely affect the planting returns of Pinellia, so how do these three diseases form? How should they be controlled? Below we will
-
Control Methods for the Four Major Diseases of Dwarf Lilyturf Cultivation
If you only hear the name dwarf lilyturf, some people might think it is a kind of wheat, a grain crop, but that is not the case at all. Dwarf lilyturf is actually a traditional Chinese medicine, and its root tubers can be used as medicinal material, so its cultivation is fairly common in our country. What
条件筛选