Symptoms and treatment of leaf and flower brown spot

Bougainvillea is also called triangular plum, because its shape is very unique, bracts and leaves are very similar, so it is named, so the main ornamental part of Bougainvillea is bracts. However, if the leaf flower suffers from brown spot disease, it will have a great impact on the ornamental value. If it is not treated in time, there will be plant death. The small series will introduce you to the symptoms and prevention methods of leaf spot disease.

bougainvillea

I. Symptoms

Bougainvillea suffered from brown spot disease, mainly in the leaves between the veins. At the beginning of the disease, there are yellow brown or dark brown round spots on the leaves, surrounded by yellow-green halo, and later the spots are irregular in shape and gradually deepened in color. At the later stage of the disease, black particles appear on the spots, which finally cause the leaves to fall off. Brown spot disease onset period to spring and early autumn more common.

II. Control methods

1. Let the plants ventilate and transmit light;

2. Pay attention to increasing or maintaining the humidity of leaves;

3. When infection occurs, the diseased branches and leaves should be cut off in time and destroyed;

4, in the early stage of infection, spray 50% of the special 1000 times solution or other fungicides, can inhibit the development of the disease.

Causes of Gardenia Brown Spot

Although gardenia flowers are beautiful and white like snow. But leaves appear brown spot disease will greatly affect gardenia beautiful image, gardenia image will be discounted, gardenia appear brown spot disease how to solve it?

Prevention of Gardenia Brown Spot

Symptoms and pathological changes: the initial leaves have pale yellow round spots, orange halo, gradually expanded into round, irregular brown spots, hidden ring, so that the leaves dry. The disease is a fungal disease caused by the infection of Pleurochaete.

The pathogen overwinters mainly by hyphae latent in diseased leaves, and the temperature and humidity are suitable in spring of the next year. The characteristic of this pathogen is that it can form a large number of sexual states during the growth season. High temperature and humidity conditions are conducive to the occurrence of diseases. During the transportation of gardenia seedlings, poor ventilation, humid environment, high incidence of disease.

Gardenia brown spot disease control methods:

1. Remove diseased leaves at any time and destroy them to reduce infection sources.

2. Chemical control. Before disease onset, spray 1% Bordeaux mixture to protect plants from infection; during disease onset, spray 75% chlorothalonil wettable powder 500~800 times solution for control. Or use alum fertilizer water (mixed with ferrous sulfate 2.5kg, bean cake 5kg, pig manure 15kg, fermented and decomposed for 10~15 days) and clean water for intermittent irrigation. 0.1%~0.2% ferrous sulfate aqueous solution can also be used for foliar spraying.

Gardenia brown spot disease should be prevented in time. One of the causes of gardenia brown spot disease is poor ventilation. It is recommended that we keep gardenia ventilated in breeding. Especially at high temperatures, be sure to pay special attention to this!

How to make the leaves black and how to solve them

Azalea is one of the most common indoor plants, but in the breeding process, due to improper plant maintenance and other reasons, azalea leaves blackened, then azalea leaves blackened how to do, let's take a look at the azalea leaves blackened reasons and solutions

What about black leaves?

Rhododendron leaves blackening, may be due to improper watering, improper fertilization, humidity is too low, improper lighting, disease invasion and other reasons caused. The following small series will introduce in detail the reasons and solutions for the blackening of rhododendron leaves. According to the cause of rhododendron leaves blackening, find the solution to rhododendron leaves blackening, in order to completely solve the problem of rhododendron leaves blackening.

1. Greenhouse cultivation

Azalea is mostly greenhouse cultivation, the soil moisture temperature requirements are relatively high, coupled with the flower, fast-growing, overdraft life, will lead to azalea leaves black. This kind of azalea basically cannot be kept alive unless it is bought back and replaced with soil, most branches and leaves are pruned, all flowers are removed, and it will only grow for one or two years, but it takes too much time and energy.

2: Improper watering

Too much or too little watering of rhododendrons can cause their leaves to blacken. Watering can not be watered too frequently, to pot soil surface when slightly dry can be irrigated thoroughly, according to the matrix to determine the watering interval, peat soil moisture strong, watering interval longer, pine needle soil moisture slightly worse, watering interval is slightly shorter, to be flexible to master it.

III: Improper fertilization

Too much or too little fertilizer can also cause azalea leaves to blacken. Rhododendron intolerance fertilizer, fertilization is best light, not excessive or too concentrated. Rhododendron fertilization principle is thin fertilizer more, that is, a little less, can be applied several times.

4: Humidity is too low

The air humidity is too low, it will also lead to blackening of azalea leaves, which is also related to conservation management. In the process of growth, it is necessary to spray water frequently to maintain the stability of environmental humidity, preferably between 60-80%. This symptom is easy to occur in dry environment.

5: Improper lighting

Azalea lighting requirements are semi-shade or scattered light, can not be placed in shade, summer strong light is also easy to cause azalea leaves injured, black, growth stagnation, serious when the whole plant death. In summer, cuckoo should be placed in a ventilated and cool place. In summer, reed curtains, bamboo curtains and sunshade nets should be used for shade. The curtains should be opened before 8 a.m. and after 5-6 p.m.

VI. Brown spot disease

Azalea may be infected with brown spot disease, which causes azalea leaves to blacken. In the early stage of disease, brown spots appeared on the edge of azalea leaves, the junction between disease and health was not obvious, light green, brown, rust red transition, with the extension of disease, the spots expanded or the whole azalea leaves turned brown, causing leaves to fall off ahead of time, even the whole azalea died, July to August, the disease was most serious. Appropriate shade at high temperature, enhance azalea growth, increase organic fertilizer, improve disease resistance.

Adhere to the principle of prevention first, spray protective fungicide 80% Dasheng wettable powder 600 times to 800 times solution, or 75% Baijunxiao wettable powder 600 times to 800 times solution. At the beginning of the disease, spray 2500 times solution of 12.5% Licorne WP or 1500 times to 2000 times solution of 25% Dirideo EC.

VII: Erythema

Rhododendron infection with erythema disease can also cause blackening of rhododendron leaves. At the beginning, rust-red spots appeared on the leaves of rhododendron, mostly on the edge or tip of the top leaves, and gradually expanded into nearly round or irregular rust-red spots. The junction between disease and health was obvious and dark brown. Black spots appeared on the diseased part at the later stage, and the damaged leaves were brittle and easy to crack. Finally, the diseased spots extended to most or the whole leaves of Rhododendron, causing Rhododendron to fall off ahead of time. From late June to August, the incidence peak period. Cut off the diseased leaves and burn them. At the initial stage of disease, spray 70% thiophanate-methyl WP 1000 times solution, or 12.5% nikacin WP 2500 times solution, or 25% diritol EC 1500 times to 2000 times solution.

How to prevent black leaves

Azalea likes warm and humid semi-shade environment and requires good ventilation. Usually can be placed in bright light maintenance, summer and early autumn high temperature season to shade, avoid sun exposure, otherwise strong light will burn leaves, but also can not be too shaded, so as not to overgrow rhododendron, affect flowering, can be placed under the shade shed or tree shade maintenance. Keep the soil moist during the growth period, but do not accumulate water. Pay attention to drainage in rainy season. When the air is dry, sprinkle water on the rhododendron and the surrounding ground to increase the humidity of the air and prevent the rhododendron leaves from drying up. Can also cover a layer of soft grass on the surface of the basin soil to prevent the sun from burning the fine fibrous roots on the surface of the basin soil. Apply decomposed thin liquid fertilizer once every 15 days or so. In order to prevent the occurrence of yellowing disease, a small amount of black alum can be added to the fertilizer solution to make the leaves green and bright. Adding 1 to 2 times of phosphorus fertilizer such as bone meal and calcium superphosphate at budding stage can promote azalea to be big and colorful.

Summary: The above is about how to do rhododendron leaves blackening, rhododendron leaves blackening reasons and solutions related to the introduction, I hope to be helpful to everyone.