Detailed Guide to Pest and Disease Control for Bonsai and Flowers
Although bonsai are prepared in advance, pests and diseases can still harm bonsai and flowers, so controlling pests and diseases for bonsai and flowers is also very important. But how can pest control be done safely for bonsai and flowers?
Chinese plum yew (Sageretia thea)
Controlling red spider mites. Among ordinary bonsai, varieties such as wild elm, Chinese plum yew (Sageretia thea), azalea, and five-needle pine are susceptible to red spider mites. If the leaves lose their green color, the leaf edges curl upward and scorch, and even only the young buds at the tips remain, then the plant has been infested by red spider mites. The cause is high humidity, high temperature, and poor ventilation. Red spider mites reproduce extremely quickly and cause severe damage, and are an important cause of plant death. Red spider mites mainly hide on the underside of leaves, and the tiny red dots are visible to the naked eye. The method for eliminating them is extremely simple, and after many years of use by the author, not a single attempt has failed. Place the affected bonsai into a jar large enough to hold it, light a coil of mosquito repellent incense, cover the mouth of the jar with plastic film, tie it tightly with string, and then make a small hole in the plastic film. Small and medium bonsai can be taken out after one hour, and large bonsai after three hours. One treatment is effective, and both adults and eggs can be killed. If a sheet of white paper is placed under the bonsai, a layer of dead red mites can also be seen.
Controlling white ants, black ants, and earthworms. Ants can bite through root hairs and make nests inside tree trunks, threatening the plant. Earthworms make nests in the pot, which also disrupts the normal growth of the root system. They are all great enemies of bonsai. The method for eliminating them: take a bucket of clean water, slowly lower the affected bonsai all the way to the bottom, with the water level above the top, and wait half an hour. Scrape the floating ants from the water surface with straw paper, and they can all be removed. Earthworms take about one hour to emerge from the soil and enter the bucket. This method is effective in one treatment, with nothing missed.
Pest and Disease Control for Bonsai and Flowers
Flower (Flower ['flauə]; plural: Flowers), a general term for plants grown for appreciation, is a modified short shoot with reproductive function, and has many kinds.
A typical flower, on a short axis of limited growth, bears the calyx, petals, and the stamens and pistils that produce reproductive cells. A flower is composed of the corolla, calyx, receptacle, and stamens and pistils, comes in a variety of colors, and some grow very brightly colored and fragrant.
Pest and disease control for bonsai and flowers.
Five common pests and diseases of potted trees:First, root rot. Most cases are caused by wounds being invaded by pathogens and improper planting management, excessive watering and fertilizing, and overly wet potting soil, which suffocates the root system and causes rot. For control, promptly dig up the original plant, cut off the rotten roots, soak them in a 5000-fold potassium permanganate solution for one hour, and then replant with fresh soil.
Second, powdery mildew. The leaves, branches, and flower buds of affected plants all have a layer of white powdery substance on the surface. For control, promptly move them to a ventilated, sunny place, control humidity, prune off diseased branches and leaves and burn them; spray a 100-fold Shabile solution, once every ten days or so, for two consecutive times. About one week after spraying, a 1000-fold ferrous sulfate solution can be sprayed as foliar fertilization to restore tree vigor.
Third, aphids. There are brown, green, black, red, and gray ones, among others. Aphids are small, and the breeding period is from March to October each year. They gather on the young tender leaves of potted trees such as banyan, Chinese hackberry, and Chinese plum yew (Sageretia thea), sucking nutrients. For control, spray with dichlorvos at 1200 to 2000 times dilution to kill them.
Fourth, red spider mites. Red spider mites spin webs on plant leaves and use their mouthparts to pierce branches and leaves and suck sap. The chlorophyll of affected leaves is destroyed, the color turns pale yellow, fine grayish-yellow spots appear on the leaf surface, and the leaves gradually wither, yellow, and fall. In some cases, even all the leaves of the whole plant drop off and the plant dies. They can be eliminated by spraying dichlorvos or dimethoate at 1000 to 1500 times dilution.
Fifth, longhorn beetles. Female longhorn beetles bite through the bark and lay eggs on the branches and trunk. The newly hatched larvae feed under the bark and, as they grow, bore into the trunk and roots. Affected plants are often hollowed out and die. For control, the location of the pest can be judged according to the excrement, and a suitable iron wire can be inserted into the insect hole to pierce the larvae to death. A cotton ball soaked in 200-fold dichlorvos solution can also be inserted into the bore hole to poison the larvae, and then the hole can be sealed with wet mud.
Common Pests and Diseases of Export Flowers and Bonsai and Their Control
There are several hundred kinds of pests and diseases harming flowers and bonsai. This article mainly introduces the important pests and diseases commonly seen in the quarantine process, some of which are quarantine pests that export flowers and bonsai are not allowed to carry. It is hoped that flower growers and flower and tree companies will pay attention to them in production practice and actively control them, so as to promote the smooth export of flowers and bonsai. I. DiseasesCommon diseases on flowers and bonsai include powdery mildew, anthracnose, sooty mold, leaf spot, rust, fusarium wilt, and root-knot nematode disease, among others. These diseases can occur on all kinds of herbaceous and woody flowers and bonsai, among which root-knot nematode disease and fusarium wilt are especially important in export quarantine. These diseases are all very serious in their harm to flowers and bonsai.
Control methods: (1) Pay attention to the disinfection of seedbeds and nursery land before planting; (2) Plant at a reasonable density and increase ventilation. Provide moderate shading during high summer temperatures; (3) Frequently investigate in the field, and immediately prune off seriously diseased branches or apply chemicals for control when disease is found. Commonly, 800-fold solutions of carbendazim, thiophanate-methyl, and thiram are sprayed on leaf surfaces. For root-knot nematodes, fenamiphos or aldicarb is applied in holes for control.
II. Pests
By comparison, pests on flowers and bonsai have greater quarantine importance than diseases. Many pests on flowers and bonsai are quarantine pests in export quarantine.
1. Scale insects. Scale insects are the most important pests in bonsai quarantine and also the most troublesome problem in quarantine treatment. The author has introduced them specifically. Recently, scale insects have also been found on plant roots, and attention should be paid to this during control.
2. Red spider mites and whiteflies. Red spider mites commonly occurring on all kinds of flowers and bonsai include Tetranychus cinnabarinus and Eotetranychus kankitus, as well as Panonychus citri, Brevipalpus obovatus, and Rhizoglyphus echinopus, among others. In recent years, the problem of whiteflies in flower and bonsai quarantine has become increasingly prominent. Bonsai exported from China to the Netherlands have repeatedly been burned or returned by the other party because whiteflies were found. Common whiteflies include Trialeurodes vaporariorum, Aleurocanthus spiniferus, and Dialeurodes citri, among others. Red spider mites and whiteflies are very small and have strong reproductive capacity, spreading rapidly on flowers and bonsai, and mostly occur on plants such as boxwood, holly, firethorn, kumquat, camellia, chrysanthemum, five-needle pine, and jasmine. To control such pests, generally spray with 20% dicofol or 40% omethoate at 1000 times dilution.
3. Thrips and aphids. Thrips cause damage in many cut flowers and seedlings, especially commonly seen in flowers such as chrysanthemum, gladiolus, and tuberose. The main ones include Frankliniella intonsa and Thrips flavus, among others. Damage by thrips is not easily taken seriously, but once it occurs it is difficult to control, because careless use of chemicals can have adverse effects on cut flowers, so control must be timely. Common aphids on flowers and bonsai include Myzus persicae, Aphis gossypii, Aphis pomi, and other long-tubed aphids and Rhopalosiphum species, among others. Plants with more frequent occurrence include plum blossom, cherry blossom, orchid, hibiscus, peach, hollyhock, firethorn, and elm, among others. Generally, when plant branches and leaves are more luxuriant or planting is denser, aphids are more likely to occur. In addition to directly harming plants, aphids can also transmit related plant viruses, and many countries prohibit plants from carrying aphids. When there are a small number of thrips or aphids in the flower center, they can be gently brushed off with a writing brush dipped in water. When aphids occur in large numbers, spray with 80% dichlorvos or 40% omethoate at 1000 times dilution to kill them.
4. Leaf-eating pests such as moths. These pests have relatively large bodies, and most feed on plant leaves and tender shoots as larvae, so their harm to the growth of flowers and bonsai is the most obvious. Common ones include Argyrogramma agnata, coffee hawk moth, slug moth, tortricid moth, snout moth, and other moths and sawflies, among other pests. All kinds of herbaceous and woody flowers and bonsai can be harmed. Last year, damage by blister beetle moths occurred in the chrysanthemum nursery of the Sun Yat-sen Mausoleum in Nanjing, China. This pest bit off the tender tips of chrysanthemums, causing tens of thousands of chrysanthemum plants to fail to bloom. For controlling such pests, pyrethroid pesticides or a mixed solution of dichlorvos and dichlorvos-killing agents are currently mostly used. In addition, the larval cases of bagworms and the cocoons of slug moths are problems often encountered in quarantine. Export bonsai are often burned entirely, or even as a whole batch, because bagworm or slug moth cases or cocoons are found in some inconspicuous place. Therefore, during daily cultivation, attention should be paid to removing them. Some other pests, such as trunk-boring pests and underground pests, also cause relatively great harm to flowers and bonsai, and attention should also be paid to their control during the cultivation of flowers and bonsai.
III. Other Harmful Organisms
Other harmful organisms mainly include: snails, slugs, small snails, and weeds on the pot surface. Weeds on the pot surface should be pulled out as much as possible before export. For the control of snails, the main point is to keep the nursery land clean, and the chemicals generally include 15% metaldehyde and methiocarb powders, among others.