A Detailed Guide to Spray Treatment Methods for Plant Pests and Diseases

When we grow plants, we often face the threat of pests and diseases, but using chemical pesticides to treat them not only pollutes the environment but also easily causes some harm to ourselves. The editor will introduce a spray method that does not use pesticides to treat plant pests and diseases.

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1. Soak 0.5 kg of plant ash in 2.5 kg of water for 24 hours, then spray the filtrate on flowers and trees. It can kill aphids on plum blossoms, roses, and pomegranate trees.

2. Spray flowers and trees with a 0.1% baking soda solution to control powdery mildew on roses, chrysanthemums, garden balsam, cotton rose, and cineraria. The control rate can reach over 80%.

3. Spray flowers and trees with a 2% urea solution once every 10 days, for 2-3 consecutive sprays. It not only kills aphids, red spiders, and other pests on them, but also makes the leaves of flowers and trees glossy and the flowers large and colorful.

Control Methods for Pests and Diseases of Foliage Plants

During their growth, foliage plants may suffer damage from pests and diseases. Affected plants not only have their growth impacted, but also have their ornamental value reduced or even lost. Therefore, the prevention and control of pests and diseases in indoor foliage plants is very necessary. This is a basic skill that all flower lovers need to master; otherwise, they will lose the truesignificance。

of foliage plants in beautifying and purifying the environment. There are many kinds of indoor foliage plants, but for each unit or household, the number used is usually not large, and management is relatively meticulous. If pests and diseases occur, although they do not easily spread to other plants, they often develop quickly on the affected plant. Therefore, the prevention and control methods for pests and diseases of these plants are mainly based on prevention, integrated control, and at the same time strengthening cultivation management; creating a good plant ecological environment, promoting healthy plant growth, and improving their own stress resistance and other effective cultivation measures.

Before all indoor foliage plants are brought indoors for display, they should undergo strict inspection. Choose adaptable, disease-resistant varieties or healthy plants and arrange them reasonably. If slight diseased leaves or a small amount of aphids, mites, or scale insects are found, physical methods should be used promptly, such as manual pruning, removing diseased leaves, or washing with soapy water and then rinsing with clean water or wiping with a soft damp cloth; scale insects can also be gently scraped off with a bamboo stick; if the damage is severe, move them outdoorsfor handling。

Indoor foliage plants should not be treated with pesticides indoors, because insecticides are generally toxic substances. If such toxic items remain or are brought into the indoor air circulation system, it will lead to various adverse consequences. As decorations, indoor foliage plants often attract people to observe their various characteristics; for example, some people may smell them, and some may touch their branches and leaves. In order to maintain good public relations, it should be stipulated that indoor decorative plants are not treated with pesticides to control pests and diseases. If some plants are damaged by pests and diseases and cannot be effectively controlled by physical methods, they must be moved outdoors, isolated from healthy indoor plants, and then given other treatments, such as chemical control or destruction. Plants brought indoors must be checked regularly, handled and controlled in time. This can reduce the degree of damage to plants, prevent trouble before it happens, and keep the indoor environment clean and hygienic with good ventilation and light transmission, so that foliage plants can remain green and fresh with high ornamental value.

1. Physical control methods

The following lists some common pests and diseases of foliage plants and gives suggestions for indoor physical control methods:

(1) Aphids:They are small, soft common insects that often damage the shoot tips and young leaves of begonias, ivy, blood amaranth, Araliaceae plants, and others. For control, leaves can be washed with water or soapy water, or the affected parts can be removed.

(2) Mites:They mainly damage the leaves of Monstera deliciosa, croton, philodendron, rubber tree, inch plant, and others, spreading from the lower leaves to the upper leaves, sucking nutrients from new buds and leaves, and causing leaf discoloration. For control, water can be sprinkled on the leaf surface to wash off the mites. Severely affected plants should be moved away immediately.

(3) Scale insects:They often damage the branches and leaves of croton, arrowroot, dragon tree, and bromeliads, and often gather on branches and leaves to suck nutrients. An environment with high temperature, high humidity, and poor ventilation and light transmission is suitable for scale insects to break out. Therefore, attention should be paid to strengthening ventilation and light transmission and improving indoor conditions. Scale insects spread only within a very small range on their own, so doing quarantine work well and not using infested materials is the most effective control measure. If scale insect damage has already occurred, scale insects can be scraped off with a bamboo stick, or the affected parts can be cut off.

(4) Thrips:They damage the leaves of begonias, hyacinths, poinsettias, and others, often causing damage near leaf stalks and veins and crawling on the leaf surface to suck nutrients. This causes leaves to lose green color and vitality. If only a small number of plants are affected, they can be wiped off with alcohol cotton or washed with soapy water.

(5) Anthracnose:It damages bromeliads, dragon tree, croton, pepperomia, rubber tree, hoya, and others. It attacks leaves and causes black spots on the leaves. To control this disease, mainly strengthen management, maintain good light transmission and ventilation, avoid pouring water over the top when watering, and water from the edge of the pot instead. If there are affected leaves, remove the diseased leaves promptly.

(6) Rust disease:It damages the leaves of Rosaceae plants and hoya. In the early stage, orange-red spots appear on the leaf surface, and in the later stage, brown spores appear on the back of the leaf. Control methods: disinfect the growing medium in advance, strengthen environmental management, maintain ventilation and light transmission, and remove diseased leaves when necessary.

(7) Brown spot disease:It damages the leaves of dragon tree, Monstera deliciosa, and palms. In the early stage of damage, small irregular brown spots appear on the leaf surface, and later they turn grayish white and gradually dry, scorch, and die. Control methods: manually prune diseased leaves and dead branches, and burn them in a centralized manner.

(8) Soft rot:It damages the leaves of hoya and fittonia. In the early stage, water-soaked spots appear on the leaf surface and leaf stalks, and then they wilt and droop, losing ornamental value. During control, attention should be paid to meticulous management, avoiding watering the leaf surface, and cutting off affected branches and leaves.

(9) Powdery mildew:It damages plants of the Asteraceae and Rosaceae families, causing leaf damage. During control, pay attention to strengtheningmanagement, maintain good indoor ventilation and light transmission conditions, and cut off diseased leaves.

2. Chemical control methods

If the above physical control methods are ineffective, the plants should be moved outdoors before chemical control. Common methods include:

(1) Foliar spraying of pesticides:According to their different insecticidal mechanisms, pesticides can be divided into three types: systemic, contact, and protective-therapeutic. Among systemic types, insecticides include omethoate and others, mainly used to control scale insects, mites, aphids, and others; fungicides include carbendazim, thiophanate-methyl, and others, which are effective against leaf spot, anthracnose, brown spot, rust disease, and others in plants. Contact insecticides include dichlorvos, pyrethroids, and others, which can kill chewing-mouthpart larvae, aphids, newly hatched scale insects, and others. Protective-therapeutic pesticides mainly form a medicinal film on the plant surface, thereby protecting, treating, or killing pests and diseases, such as lime sulfur mixture, sulfur suspension concentrate, polymer films, and others.

(2) Soil application of pesticides:The active ingredients of this type of pesticide can be absorbed by plant roots and transmitted to all parts of the plant to kill leaf pests and diseases, or directly kill pests and diseases in the soil, such as formaldehyde and other agents.

Control of Pests and Diseases of Ground Cover Plants

Ground cover plants often form garden landscapes through their mass beauty, and dense planting is often used when planting them. Therefore, great attention must be paid to the prevention of their pests and diseases.

1. Chlorosis

When ground cover plants are planted in unimproved alkaline soil, leaf chlorosis occurs frequently, which not only affects ornamental value but can also cause death in patches in severe cases.

Control methods:

1. Improve the soil before sowing.Before planting ground cover plants, apply more organic fertilizer to the soil to lower the soil pH and increase soil organic matter content and fertility. This is a basic and effective method of soil improvement.

2. Do follow-up fertilization well.Continue to regulate soil pH through follow-up fertilization. Generally, the method of alternately spraying potassium dihydrogen phosphate solution and a mixed soaking liquid of decomposed soybean cake, green grass, and ferrous sulfate is used. If this is consistently done during maintenance, severe chlorosis generally will not occur. If proper control methods have not been taken and chlorosis has already appeared, chlorosis can also be alleviated or completely cured through treatment. During the growing season, a 600-times concentration potassium dihydrogen phosphate solution can be applied at the root at a dose of 25 grams per plant (if the plant exceeds the size specification of 60 cm to 50 cm, the dose can be increased accordingly); at the same time, a 100-times concentration solution can be used for foliar spraying once a week for 3 consecutive months. Practice has proved that for plants that are chlorotic throughout the whole plant but whose leaves have not yet shrunk, they will all turn green again, and at this time measuring the soil pH will show a clear decrease.

Potassium dihydrogen phosphate is a strongly acidic compound fertilizer with a pH between 4.2 and 4.6, containing 28% potassium and 22% phosphorus. It can not only provide ground cover plants with more phosphorus and potassium fertilizer, but also has a certain effect on regulating soil acidity and alkalinity and improving the availability of various mineral elements in the soil. In addition, in some areas the soil is acidic but has low organic matter content, and poor soil can also cause chlorosis in ground cover plants, so organic fertilizer should be applied and lime should be applied appropriately to control it.

2. Red spiders, aphids

These insects are tiny, but they often cause fatal damage to the key parts of plants (such as leaf bases and flower buds). In spring, large numbers of mites and aphids often appear on the flowers and leaves of rhododendrons and chrysanthemum greens, causing leaves to show yellow-green mottling and even leaf drop. In severe cases, they bore into the flower buds, causing seemingly plump buds to wither before opening.

Control methods: 20% abamectin 2000-times solution or 40% acephate emulsifiable concentrate 1000-times solution can both be used for control. The main thing is to observe pest conditions and control them promptly once discovered, once a week, 2-3 times.

3. Gray mold, sooty mold, brown spot disease

Some ground cover plants are located at the bottom layer of the community, where the environment is generally shady and damp. Warm and rainy weather in the rainy season can lead to the occurrence of gray mold, sooty mold, and brown spot disease, which can seriously affect the ornamental effect of ground cover plants.

Control methods: The control agents can be 800-times 75% chlorothalonil, 500-times 50% carbendazim and 60% zineb, 200-times equal-strength Bordeaux mixture, and 700-times 50% thiram.

4. Cutworms, white grubs, and others

These underground pests can cause damage to some tender herbaceous ground cover plants and should be controlled promptly to maintain uniform coverage of the ground cover.

In short, the prevention and control of pests and diseases in ground cover plants focuses on prevention, and the key is to create a suitable growing environment for ground cover plants and improve their health level. With the increase in flower colors and varieties and the improvement of cultivation and management measures, it is believed that ground cover plants will add more color to beautiful ecological environments.