What are the methods for preventing and controlling pests and diseases in flower cultivation?
The main principle of plant pest and disease control is "prevention first, comprehensive control." The goal can be achieved through small things in daily life. Below, Xiaolin introduces pest and disease control methods for flower cultivation, hoping to help fellow flower enthusiasts.
When buying flowers or seeds, do not purchase plants and seeds that have pests or diseases. When starting cultivation, the soil needs to be disinfected to prevent pathogens and insect eggs carried by the soil from infecting the plants. Disinfect frequently used pruning shears and tools to prevent diseases from spreading between plants.
Maintain a clean, sanitary, and well-ventilated environment. Promptly remove diseased and pest-infested leaves and branches from plants, and dispose of them in a centralized manner by burning. Strengthen pest control, as the damage caused by pests is often greater than that caused by diseases.
When selecting plants for cultivation, choose plants that grow vigorously and have strong resistance to pests and diseases; do not choose plants that are easily affected by pests and diseases.
When fertilizing, pay attention to the ratio between fertilizers. Nitrogen fertilizer must not be applied in excess, otherwise plants tend to grow excessively and their resistance to pests and diseases declines.
For densely growing plants, proper pruning and thinning of branches are needed so that the interior of the plant can receive ventilation and light, which can reduce the occurrence of pests and diseases.
Water remaining on leaf surfaces for a long time will facilitate infection by diseases, so ventilation should be strengthened to keep plant leaves dry.
For plants prone to disease, timely treatment should be carried out in the early stages of onset, and protective spraying should be done regularly.
Further reading:
Methods for caring for weak bonsai raw stumps
Weak stumps refer to tree stumps that already have branches and leaves but have not grown roots, produce no second flush of sprouts or latent buds in the same year, cannot withstand drought, sun exposure, damage, or frost, and are declining in growth, with leaves that are rather small, dull in color, and lacking vitality. Tree stumps that are dying from drought, pests and diseases, fertilizer burn, or chemical burn are also weak stumps.
Weak stumps must be cared for with extra caution. The placement site should be cool and moist, and the soil should be loosened frequently to maintain good permeability of the potting soil. The potting soil should be moist, neither soggy nor dry, and especially must not dry out completely and lose water.
In summer, sunlight exposure must be avoided to reduce evaporation and maintain tree growth. Weak stumps have few branches and leaves, so there is no need for physiological pruning, and fertilizing is even more out of the question.
In winter, the main focus should be on frost protection, and care measures should be strengthened. If it can survive the severe winter cold and sprout spring buds the next year, or if it can produce a second flush of buds or autumn buds, it indicates that roots have formed, and there is hope for survival; it will gradually grow normally and turn from weak to strong.
Growing plants not only pleases the eye but also "nourishes the mind." That is all for today's knowledge about flower cultivation. If you also have your own views, you can share and discuss them with everyone in the comments section. For more flower cultivation knowledge, visit Huinong Classroom.
Prevention and control of pests and diseases in autumn flower cultivation
Because daylight hours in the Northern Hemisphere noticeably shorten in autumn, short-day flowers that do not particularly like light can be planted at this time, especially plants in the Asteraceae family among herbaceous plants: Aster novi-belgii, Gaillardia, Rudbeckia hirta, marigold, and so on. In addition, common plants such as dahlia, cockscomb, salvia, impatiens, petunia, canna, begonia, geranium, dwarf sunflower, Amaranthus tricolor, and verbena are also suitable for October cultivation. Among woody plants, Milan, poinsettia, jasmine, and the aquatic flower water lily can also be cultivated in October. In October, affected by environmental changes, the cultivation methods for other plants should also be appropriately adjusted. Wang Hexiang told reporters that autumn flower care should pay more attention to the following aspects.In autumn, daylight hours noticeably shorten and sunlight becomes milder. Some plants that were originally shade-loving, such as Boston fern, Brazilian wood, peacock arrowroot, pothos, and Brazilian iron, which are afraid of sun exposure in summer, can be placed outdoors to get more sun so as to strengthen photosynthesis and accumulate nutrients.
In autumn, water evaporates less, so even some water-loving plants should have their irrigation frequency and water volume reduced, otherwise there is a risk of root rot.
People are used to placing flowers and plants outdoors all day in summer, but after October frosts already occur at night. When the temperature is below 5—10°C, flowers and plants must be moved indoors. Also, many herbaceous plants have by this time reached the seed-setting stage, so mature and plump seeds can be selected and kept to prepare for sowing next year.
The characteristic of autumn fertilization is to apply more phosphorus and potassium fertilizer and less nitrogen fertilizer to promote plant root growth. For common autumn pests such as aphids, red spider mites, and scale insects, vinegar and essential balm can be mixed with water at 1:10 to kill insects, while for common autumn diseases such as powdery mildew and black spot, prevention can be achieved by strengthening ventilation.
After the beginning of autumn, moderate temperature and humidity and good light create favorable conditions for the breeding, growth, and infection of some pathogens, often causing certain flowers to suffer serious harm. Several common diseases and their symptoms and control methods are introduced below:
Powdery mildew
Flowers such as cineraria, Chinese rose, dahlia, goji, impatiens, zinnia, large-leaf plants, and boxwood suffer the most. The affected parts first show scattered small white spots, which then gradually expand and spread, and develop very quickly. Under suitable conditions, in 7~10 days the lesions can cover the entire leaf, and the leaf surface is covered with a layer of white powdery material, as if frost has fallen. In severe cases, the leaves wither and fall early. The plant loses photosynthesis, resulting in fewer, smaller, and paler flowers, and some even fail to bloom at all. This disease develops quickly and causes severe damage under conditions of overly dense stems and leaves, muggy weather, poor ventilation and light transmission, and moist soil.
Control methods: 1. Improve ventilation and light conditions; apply more phosphorus and potassium fertilizer, avoid over-application of nitrogen fertilizer, do not water excessively, and even more so do not let water accumulate in the pot soil; of course, do not let it lack water either; and promptly remove diseased leaves and diseased buds, pull out diseased plants, and burn them in a centralized manner. 2. Chemical control. At the initial stage of the disease, some flowers can be sprayed with 1:1:140 equal-strength Bordeaux mixture, or 25% triadimefon 1500x solution, 70% thiophanate-methyl 1200x solution, or 50% Tuzet 1500x solution. Alternating the above agents can improve control effectiveness. In severe cases, spray again after 7 days, for 2~3 consecutive sprays.
Brown spot disease
It also mainly harms leaves. At the initial stage, brown spots appear on the leaf surface, and afterward the lesions gradually expand and merge into large spots. Because the lesions are restricted by leaf veins, they are mostly irregular in shape. There is a faded halo on the outer edge, the margin is reddish-brown, and the center is grayish-white. In the later stage, small black dots (pycnidia) form in the center of the lesions. The leaves of affected plants tend to fall off, and in severe cases not a single leaf remains, and the diseased plant gradually dies entirely from bottom to top. Flowers such as azalea, narcissus, jasmine, lilac, osmanthus, Chaenomeles speciosa, photinia, and lotus suffer relatively severe damage.
Control methods: 1. Promptly prune diseased branches and leaves, burn them in a centralized manner, and reduce the source of reinfection. 2. Chemical control. After the disease occurs, promptly spray 80% captafol 500x solution, 65% zineb 800x solution, 12.5% diniconazole wettable powder 1000x solution, 70% thiophanate-methyl 1200x solution, etc., once every 7~10 days, for 2-3 consecutive sprays.
Flower rot
It mainly harms flowers, flower buds, and fruits, and can also harm leaves. After leaves are affected, small reddish-brown lesions appear, which then gradually expand, causing the diseased parts to produce large amounts of grayish-white mold. As soon as flower buds appear, they can become infected and rot, and diseased flowers wither to a yellowish-brown color. This disease is likely to occur under conditions of abundant autumn rain, high humidity, and frequent fog. This disease causes relatively great harm to dahlia, cockscomb, Chinese rose, crape myrtle, zinnia, impatiens, and fruit-bearing flowers such as pomegranate.
Control methods: 1. During continuous rainy weather, rainproof measures should be taken, and flower buds and flowers must absolutely not be subjected to rainwater. Normally, cultivation management should be strengthened, more phosphorus and potassium fertilizer should be applied, pruning should be reasonable, and ventilation and light transmission should be enhanced. 2. Chemical control. Spraying 3~5 degrees Baumé lime sulfur mixture before the disease occurs can provide protection and prevention. At the initial stage, spray 5% Tian'an aqueous solution 500x, 50% Tuzet wettable powder 1500x, or 75% chlorothalonil 1000x. In severe cases, spray once every 7-10 days, for 2~3 consecutive treatments.
1. Control water and fertilizer: One month before lifting the flowers, stop applying heavy fertilizer and watering heavily. Half a month before lifting, stop fertilizing and control watering, generally to the extent that leaves wilt at noon and recover in the evening, so as to control the growth state of the flowers, enhance the damage tolerance of the tender parts of the flower plant, and at the same time prevent the soil ball from breaking apart, thereby increasing the survival rate. Especially for flowers with fleshy stems and leaves, the amount of watering should be controlled even more.
2. Lift the flower ball: When lifting the flowers, the size of the soil ball should be determined according to the size of the flower crown. Generally, the surface area of the soil ball should be slightly larger than the flower crown. For woody flowers with taproots (such as rubber tree and pomegranate), the soil ball should be deeper when lifted, while for herbaceous flowers with fibrous roots (such as kalanchoe and Alocasia), it can be shallower, but the root system should be dug out as completely as possible to minimize root damage.
3. Potting: After the flower plant is lifted out, wet the outer periphery of the soil ball with water according to the size of the flower pot, peel off excess soil so that the diameter of the soil ball is slightly narrower than the diameter of the flower pot by 2 cm to 4 cm, and the height of the soil ball is lower than the height of the pot by 3 cm to 5 cm. Place broken tile pieces at the bottom of the pot to cover the drainage hole, fill in 2 cm to 4 cm of potting soil, and add some hoof and horn pieces. After properly pruning the root system, gently place the soil ball with the flower into the pot, and fill in potting soil firmly around it.
4. Management: After potting, cut off some old leaves to reduce water evaporation. Water thoroughly, and place in a shaded area for care, often spraying clean water on the leaves to lower temperature and increase humidity. After 15 days to 20 days, normal management can be resumed.
How should flower diseases be prevented and controlled? Requirements for the principles of flower pest and disease control
In the previous two articles, we discussed the harm of pests to flowers and the morphological characteristics of pests. Quite a few flower enthusiasts left comments saying they wanted to know how to prevent and control pests and diseases in flowers and how to grow flowers well. In fact, during the growth and development of flowers, due to the influence of the external environment, they often develop poorly, and this can cause leaf deformation, various spots, and even death. Therefore, pest and disease prevention and control work is imperative. Below, the Huinong website editor talks with you about the principles and requirements for flower pest and disease control.
1. Choose a suitable cultivation environment
Under normal circumstances, flowers should be planted in a ventilated and sunny place. Where light, temperature, and humidity can be reasonably regulated, the occurrence of pests and diseases will be relatively reduced.
Promptly remove remnants of diseased and pest-infested plants and dead branches and fallen leaves, and destroy them in a centralized manner. During production operations, avoid repeated contamination. Pruning, intertillage, weeding, and pinching must be reasonable and scientific, and tools and hands must be prevented from transmitting pathogens to healthy plants. Diseased soil and pots must not be reused without disinfection.
2. Choose excellent cultivation seedlings
When planting, choose disease-free seedlings, or seeds that are excellent and strongly resistant to pests and diseases. Some pests and diseases spread and expand along with propagation materials such as seeds. For the control of such diseases, cultivating and selecting seeds free of pests and diseases must be taken as an important measure. At the same time, the soil should be disinfected; weeds should be frequently removed to eliminate sources of pest and disease infection.
3. Strengthen scientific daily management
Strengthen scientific management of soil, fertilization, and watering. Reasonable and appropriate fertilization and irrigation will make plants grow robustly. When using organic fertilizer, it must be fully decomposed to reduce sources of infection; if using inorganic fertilizer, be sure to pay attention to the balance among elements to promote robust plant growth and enhance disease resistance. The method, frequency, amount, and timing of watering are all related to plant growth and development and stress resistance.
4. Scientifically control pests and diseases once discovered
There are generally 3 types of control methods:
(1) Biological control
Control methods using fungi to treat diseases, fungi to treat insects, or insects to treat insects.
(2) Physical control
Mainly through methods such as heat treatment, mechanical barriers, and radiation irradiation to prevent and control pests and diseases, such as covering with plastic film in early spring.
(3) Chemical control
Simply put, it means using pesticides. The operation is simple and the effect is remarkable, but it causes relatively greater environmental pollution. Therefore, pesticides with low toxicity, high efficiency, and low pollution should be selected for pest and disease control, and pesticides must not be applied indiscriminately.
The above is the Huinong website editor's summary of the principles and requirements for flower pest and disease control. Have you all learned it? If you want to learn more agricultural technical knowledge, please follow Huinong Classroom!