It's the right time for flower pest and disease control, and disaster prevention should start early
Spring pest and disease prevention for flowers is especially important
Spring is an important stage for flower sowing and seedling raising. As the weather warms and temperatures rise, pests and diseases are about to enter a peak period. The quality of seedlings determines the quality of future finished flowers, so spring pest and disease prevention is especially important. The reporter recently interviewed some industry insiders and asked them to offer suggestions for pest and disease prevention in spring flower production.
High temperature and high humidity: beware of disease occurrence
In March and April, flower production in the north is generally still inside greenhouse facilities, but at this time companies have already gradually reduced heating, and the temperature inside the facilities begins to drop, yet humidity remains very high, making it easy for fungal diseases such as gray mold and downy mildew to break out. Dong Yuguang, plant protection technical manager of Syngenta, told the reporter that greenhouse production in the north of potted flowers such as Phalaenopsis, Cymbidium, and Anthurium requires high-humidity conditions and is very prone to fungal diseases. Although companies can avoid infection by cutting off flower stalks, he believes the best method is still to ventilate and reduce humidity in a timely manner when the weather is good, or to apply protective fungicides containing cyprodinil, such as chlorothalonil. If plants are found to have already been infected, chemical agents containing fludioxonil, such as "Huiyou," should be used for control.
In addition to the above diseases that may occur in southern flower production, due to high temperature and high humidity, flower seedlings are prone to leggy growth, and stems are often affected by some soil-borne diseases, such as damping-off and Rhizoctonia rot. To prevent these diseases, you can directly water with "medicated water" containing fungicides at the first watering, or mix the substrate or soil with fungicides when sowing.
At present, temperatures in subtropical coastal areas such as Guangdong and Hainan are very high, making flower Phytophthora blight prone to breaking out, and it often occurs during the cultivation of some Dendrobium orchids. Flower Phytophthora blight is extremely destructive. In addition to using agents such as mancozeb to disinfect soil and substrate for control, chemical agents containing propamocarb can also be sprayed in the early stages of the disease for control.
In addition, in terms of physical control, greenhouse humidity should be controlled as much as possible to avoid water droplets remaining on plant leaves for a long time. When using sprinkler irrigation or nozzles to water, it is best to do so in the morning so that water droplets on the plants dry before evening arrives. Use a cultivation substrate with good drainage, and avoid overwatering, otherwise it will lead to root rot. Try not to mix substrate with soil, because most soil contains pathogens that cause plant root rot.
Prevention first, strong seedlings as the foundation
Although various chemicals can be applied to control pests and diseases after they occur, distributors still advise flower production companies to focus on prevention, put effort into management, and select seedlings with strong disease resistance. Yang Liu, general manager of Zhengzhou Biaodian Chemical Co., Ltd., believes that in addition to using some broad-spectrum insecticides for prevention, companies can also apply some growth regulators that help rooting as well as some base fertilizers that improve soil and activate microorganisms. Cao Yadong, manager of the horticulture department of Beijing Leili Group, said that potted flowers are often given inorganic fertilizers, which can easily lead to a decrease in soil pH, an increase in pests and diseases, and weakened plants. At this time, applying some biological fertilizers that improve the soil environment is a good approach. As a flower production company, Bao Qingsong, a technician at Beijing Florascape Co., Ltd., said that chemical control is a last resort, and pests such as thrips are very difficult to control. Companies should strengthen fertilizer and water management, avoid providing an environment for pests and diseases to occur, and focus on prevention rather than relying entirely on chemicals.
Control methods for common flower pests and diseases in summer
I. Occurrence situation
Black spot: occurs on rose and pothos, among which the average incidence rate on rose leaves is 15.2%; the average incidence rate on pothos leaves is 6.67%.
Anthracnose: occurs on hydrangea, chrysanthemum, and Calathea makoyana, among which Calathea makoyana is more severely affected, with an average leaf incidence rate of 31.5%, and up to 50% at the highest; hydrangea has an average leaf incidence rate of 8.2%, and up to 15.2% at the highest; chrysanthemum has an average leaf incidence rate of 9.62%, and up to 20% at the highest.
American leafminer: in the survey, the average leaf damage rate on peony was 13.16%, and up to 33% at the highest; 4.39 live larvae per 100 leaves.
Scale insects: in the survey, 10.16 live insects per 100 leaves on broadleaf lady palm, and up to 26 at the highest.
Thrips: occurs more severely on small-leaved fig. The average leaf damage rate is 20-30%, with about 30 live insects per 100 leaves, and up to over 100 at the highest.
Spodoptera litura: in the survey, the average damage rate on rose was 2.9%, with 62 live insects per 100 flowers.
II. Occurrence trend analysis
(1) Flower planting varieties are diverse, planting areas are scattered, planting periods differ, and the occurrence periods of pests and diseases are relatively complex.
(2) From April to June, affected by disastrous thunderstorm weather, diseases occur more severely, and certain pathogenic bacteria remain.
(3) According to the forecast of the Guangzhou International Professional Meteorological Observatory: the overall weather trend in Guangzhou during the post-flood season after 2005 is: total rainfall from July to September is slightly above normal; the cold dew wind belongs to a relatively light year; there are 3-4 tropical cyclones affecting Guangzhou and they are concentrated from July to September. Therefore, it is expected that black spot and anthracnose will occur at a moderate to severe level, and American leafminer, scale insects, thrips, and Spodoptera litura will occur at a moderate level.
III. Control recommendations
(1) Agricultural control measures:
1. Promptly remove diseased plants and diseased leaves of black spot and anthracnose, and destroy them centrally; manage fertilizer and water reasonably to reduce the spread of pathogenic bacteria.
2. Pay attention to ventilation and air permeability in greenhouses, control the temperature and humidity inside the greenhouse, and inhibit the occurrence and spread of diseases.
(2) Chemical control:
Black spot: spray with 25% myclobutanil at 8000 times dilution or 10% Score at 1500 times dilution, continuously spraying 2-3 times every 7-10 days.
Anthracnose: spray with 80% Daconil M-45 wettable powder at 600 times dilution or 25% Sportak at 500-1000 times dilution. Apply once every 7-10 days, continuously applying 2-3 times.
American leafminer: choose 1.8% abamectin at 1000 times dilution or 40% Lvcaibao at 1000 times dilution for spraying.
Scale insects: you may choose 40% Supracide emulsifiable concentrate or 40% Sujieke emulsifiable concentrate at 1000-1500 times dilution for spraying.
Thrips: you may use 10% Yashijing at 1000 times dilution or 40% Sujieke at 1000-1500 times dilution for spraying.
Spodoptera litura: use Chongwenyihao at 1000-1500 times dilution or 20% Mimic at 1500 times dilution for spraying in the evening.
Peony pest and disease control methods Peony edible value
Peony, also known as Jiangli and Licao, belongs to the order Dilleniales, family Ranunculaceae, genus Paeonia, and is a perennial herbaceous flower. The tuberous roots grow from below the root crown, are fleshy, thick, spindle-shaped or long-columnar, 0.6-3.5 cm thick. Peony petals are obovate, the floral disk is shallowly cup-shaped, the flowering period is from May to June, and flowers generally bloom singly at the top of the stem or near the leaf axil at the top. The original species has white flowers and 5-13 petals. Next, let's look at the methods for controlling peony pests and diseases as well as the edible value of peony.
Peony pest and disease control methods
The main peony diseases include peony gray mold, peony brown spot, peony red spot, and peony rust.
Symptoms of peony rust: in the early stage of the disease, there are yellow and yellow small granules on the back of the leaves, namely the urediniospore piles of the pathogen. Later, circular, elliptical, or irregular grayish-brown lesions appear on the leaf surface, with a diameter of 4-12 mm, and the lesions have concentric rings and small dots. On the back of the leaves, cylindrical reddish-brown bristle-like structures grow from the urediniospore piles, 1-1.5 mm long; these are the teliosori of the pathogen.
Peony pests
Scarab beetles
Pest species and damage situation: there are many kinds of scarab beetles that harm peonies, such as the black velvet chafer, the apple green chafer, and the yellow-haired chafer. Their adults harm peony leaves and flowers; the larvae, white grubs, have a body nearly cylindrical and curved into a "C" shape, are milky white, with a yellowish-brown head, 3 pairs of thoracic legs, and no abdominal legs. They feed on peony roots, and the wounds they create also create conditions for Fusarium infection, leading to root rot.
Scale insects
Scale insects are also called scales. There are several kinds of scale insects that harm peonies, such as the cottony cushion scale, the Japanese wax scale, the long white scale, the mulberry white scale, the peony round scale, and the arrowhead scale. Scale insects suck the sap of peonies, causing the plants to grow weakly and the branches and leaves to turn yellow. When individual branches are found to be harmed by scale insects, they can be brushed off with a soft brush, or the infested branches can be cut off and burned, and spraying should be timed during the peak hatching period of the eggs. Newly hatched insects have not yet developed wax on their surface and are easily killed. It is best to strengthen quarantine and strictly prevent the introduction of seedlings carrying insects.
Aphids
After peonies sprout in spring, aphids fly in to cause damage, sucking the sap of the leaves, causing the damaged leaves to curl and turn yellow. After the seedlings grow, aphids often gather on tender shoots, flower stalks, and the backs of leaves, causing the stems and leaves of the flower seedlings to curl and shrink, and even the whole plant to wither and die. Spraying 40% dimethoate emulsion at 1000-1500 times dilution, or 80% dichlorvos at 1500-2000 times dilution, or 50% menazon emulsion at 1000-1500 times dilution can suppress aphid disasters in the short term.
Peony edible value
1. Peony flower porridge.
The method is: select 6 grams of shade-dried white peony flowers, 50 grams of japonica rice, and a little white sugar. Cook the japonica rice with an appropriate amount of water, then add the peony petals and cook for another 2-3 minutes before taking it out of the pot, then add white sugar and it is done. Refreshing and delicious, fragrant and tempting, drinking peony flower porridge can nourish blood and regulate menstruation, and treat conditions such as liver qi disharmony and qi-blood deficiency with flank pain, irritability, and menstrual abdominal pain.
2. Peony flower cake.
In the Qing Dynasty, Lady Derling once recounted in "Imperial Incense" that Empress Dowager Cixi, in order to nourish her appearance and prolong her life, specifically mixed peony petals with eggs and flour and then fried them into thin cakes to eat. In addition, peony flowers can also be used to make peony flower soup, peony flower wine, peony carp soup, peony flower fritters, etc. The preparation methods are simple, delicious, and highly effective.
3. Peony flower tea.
The preparation method of peony flower tea is as follows: pick peony flowers and place them in a cool, dry indoor place. When drinking, take one teaspoon of dried petals, brew with boiling water, and you may add rock sugar, honey, green tea, brown sugar, etc. to drink together. In addition, peony and Rehmannia tea can nourish yin and clear heat, soften the liver and soothe the liver. Preparation method: 2 grams of peony flowers, 3 grams of Rehmannia, and 3 grams of green tea, brew with boiling water and drink. [11]
Medicinal value
The roots of peony are fresh, crisp, and juicy and can be used medicinally. According to analysis, peony roots contain paeoniflorin and benzoic acid, and their uses vary by species. Traditional Chinese medicine believes that Baishao in Chinese materia medica mainly refers to the root of peony, which has antispasmodic, analgesic, and menstruation-promoting effects. It is effective for conditions such as abdominal pain in women, gastric spasm, dizziness, gout, and diuresis.