A detailed guide to Phalaenopsis cultivation and management techniques and the main pest and disease control methods

The daily care and management of Phalaenopsis has already been covered for you by the Huinong website editors. We do not know whether our flower-growing friends have mastered those previous articles. In the following text, the editor will guide everyone through learning the cultivation and pest and disease control techniques for a new Phalaenopsis variety, "Mantianhong".

1 Seedling-stage cultivation and management techniques

1.1 Selection of planting material as pre-planting preparation

For the growing medium, select high-quality imported sphagnum moss (to reduce black head disease). The sphagnum moss must be soaked and rinsed in clean water 3 times. The first time, soak and rinse with 80°C hot water for 30 min to 40 min (to disinfect and sterilize, and reduce the occurrence of weeds and pathogens), then soak and rinse with cold water for more than 30 min, then dehydrate with a centrifuge or press-dryer until no water droplets can be squeezed out, and it is ready for planting Mantianhong.

1.2 Small seedling cultivation and management

1.2.1 Standards for removing tissue-cultured seedlings from the flask

Mantianhong mericlones obtained through tissue culture can maintain the characteristics and traits of this variety. The standards for removing tissue-cultured seedlings from the flask are: the plant is robust, the monopodial stem is relatively obvious, the leaf color is emerald green, the leaf number is 3 to 5, and the leaf width is 1.5 cm to 2.5 cm; the root number is 3 to 5, the root length is 1.0 cm to 5.0 cm, and the root system is thick and vigorous.

1.2.2 Removing tissue-cultured seedlings from the flask and planting them

When planting seedlings, remove impurities from the sphagnum moss and loosen it. First place a small amount of sphagnum moss beneath the root system, then use sphagnum moss to wrap the small seedling's roots and monopodial stem, being careful to prevent breaking the roots, and take care not to wrap the crown or expose the entire base of the root system. After wrapping with sphagnum moss, plant the small seedling upright in the exact center of the pot, and make sure the sphagnum moss is about 1.0 cm below the pot rim, with the degree being that the soft pot feels firm and elastic when pinched by hand. After planting, place the leaves facing the diagonal of the seedling tray. Generally, every 10 kg of sphagnum moss plants 1800 to 2000 plants.

1.3 Medium seedling cultivation and management

After small seedlings have grown for 4 to 6 months, when the distance between two leaves is 8 to 12 cm, the leaf width is 4 to 5 cm, the leaf number is 4 to 5, the leaf color is deep green, the leaves are thick and upright, and the root number is >=4, they can be transferred to Φ7.5 cm transparent soft plastic pots for planting.

Before repotting small seedlings, water should be controlled to keep the sphagnum moss slightly moist, and they should be graded by size. When taking out the seedlings, gently pinch around the 1.5-inch soft pot by hand to separate the root system from the pot wall, and carefully take out the small seedling. Then take a 2.5-inch soft pot and place 2 to 3 foam pellets in the bottom of the pot (if you can master the planting method of firm on top and loose at the bottom, the foam pellets may be omitted; the same below), then plant according to the flask seedling planting method, and make sure the sphagnum moss is about 1.8 cm below the pot rim.

1.4 Large seedling cultivation and management

After medium seedlings have been cultivated for 4 to 6 months, when they have grown to 4 to 5 leaves, the distance between two leaves is 18 cm to 20 cm, the leaf length is 9 cm to 11 cm, the leaf width is 5 cm to 7 cm, the leaf color is glossy green, the leaves are thick and upright, and the root system is full, water may be appropriately controlled in preparation for transferring them to Φ10.5 cm transparent soft plastic pots for planting. After repotting and planting, place them in a 32 cm x 43 cm 12-hole seedling tray, leaving 1 row of 4 holes empty in the middle of the tray, with 8 plants actually placed per tray. The leaves should extend in a north-south direction. Generally, every 10 kg of sphagnum moss plants 350 to 400 plants.

2 Cooling temperature to promote flower bud differentiation

2.1 Key points of high-mountain flower forcing management techniques

In Guangdong, Fujian and other places, high-mountain climates at an altitude of about 700 m to 800 m are generally used for cooling-temperature flower forcing; other special climate environments may refer to this for implementation. For National Day and Mid-Autumn Festival flowers, the time to go up the mountain is generally 130-140 days before the peak flower-use day; for Spring Festival Lunar New Year flowers, going up the mountain is generally about 160 days before the Spring Festival.

2.2 Management during the flower-forcing period using air conditioning on flat land

Where there is no high-mountain base or it is inconvenient to use one, air conditioning can be used for cooling-temperature flower forcing. Air-conditioning cooling-temperature flower forcing is more controllable and allows potted flower production to be scheduled year-round. For National Day and Mid-Autumn Festival flowers, the cooling-temperature start time is generally 130-140 days before the peak flower-use day; for Spring Festival Lunar New Year flowers, the cooling-temperature start time is generally 150-160 days before the Spring Festival.

3 Field management from the flower stalk elongation stage to the flowering stage

After flower forcing, for Mantianhong plants with flower stalks, care should be taken to make the flower stalk bend toward the south; for double flower stalks, the longer flower stalk should be dominant. When the flower stalk grows to 10-25 cm, place them in zones according to flower stalk length, and use 45 cm plastic-coated iron wire to fix the flower stalk so that it grows vertically upward. After flower stalk plants show buds, reduce the number of times they are moved as much as possible to avoid bruising the buds and reduce bud abortion.

4 Regulation and control of the cultivation environment

4.1 Environmental management for small seedlings

Within 20 d after planting Mantianhong flask seedlings, the light intensity must not exceed 8000 lx; after 20 d, control it at about 10 k lx; after 2 months, it can be increased to about 15000 lx. After planting, the nighttime temperature should preferably be controlled at 23-25°C. If the temperature is below 20°C, the leaf color of Mantianhong turns red and growth is slow. Therefore, in winter and spring, the nighttime temperature should generally not be lower than 20°C, and the daytime temperature should preferably be controlled at 28-30°C. The relative humidity should preferably be maintained at 80-90% within 15 d after planting, and then gradually reduced to 70-85%. In addition, attention should be paid to strengthening ventilation.

4.2 Environmental management for medium seedlings

Newly repotted medium seedlings have relatively poor stress resistance because their root systems and leaves are damaged to varying degrees. In addition to sterilization, disease prevention and water control, a cool and ventilated environment should also be created to allow them to resume growth. When new roots have not yet grown, control the light intensity below 1000 lx; after new roots grow, it can be increased to 15000 lx-20000 lx. During the growth period of medium seedlings, the nighttime temperature should be controlled at 23-25°C, and the daytime temperature at 28-30°C. The relative humidity should preferably be 70-85%.

4.3 Environmental management for large seedlings

During the growth period of large seedlings, the light intensity should be controlled at 12000 lx-20000 lx in summer. In autumn and winter, when the daytime temperature inside the greenhouse is below 27°C, it can be controlled at 25000-30000 lx. Temperature control should be 32-25°C day and night, and relative humidity should preferably be 65-85%.

4.4 Environmental management from the flower stalk elongation stage to the flowering stage

From the flower stalk elongation stage to before flowering, the light intensity can be maintained at 20000-30000 lx. After the start of flowering, the light intensity should preferably be reduced to between 15000 lx-20000 lx, which helps prolong the flowering period. From the flower stalk elongation stage to the flowering stage, the nighttime temperature should be regulated at about 20°C, and the daytime temperature at 26-28°C. When the heater or fan is not running, circulating fans should be started to maintain air movement and reduce the occurrence of pests and diseases; the relative humidity should preferably be controlled at 65-80%.

5 Fertilizer and water management

5.1 Fertilizer and water management for small seedlings

In the third week after planting, new roots begin to grow. If the sphagnum moss in the pot is relatively dry and only a small amount of water droplets is seen at the bottom or on the wall of the pot, water half-thoroughly with 3000-fold diluted Cuiyun Vigor B1 liquid or 5000-fold diluted 10-30-20 (N:P:K, same below) Peters fertilizer. After that, every 7-10 days, water the roots with 3000-4000-fold diluted 20:20:20 water-soluble quick-acting fertilizer. In summer and autumn, watering is generally done in the morning. In winter and spring, when the temperature is relatively low, watering can be done at noon, and the water temperature should be controlled at about 20°C.

5.2 Fertilizer and water management for medium seedlings

After 25 d-30 d from repotting, the plants have new roots growing, and some new roots have reached the pot wall. When the sphagnum moss is relatively dry, apply the second fertilizer. After that, in winter and spring and on cloudy and rainy days, generally every 10 d-15 d apply 2000-fold to 2500-fold diluted 20:20:20 water-soluble fertilizer solution as half-thorough watering; in summer and autumn and on clear days, every 7 d-10 d apply 2000-fold to 2500-fold diluted 20:20:20 water-soluble fertilizer solution as thorough watering. In addition, Ca and Mg elements should be appropriately supplemented to increase leaf thickness. Water management changes according to the plant's water requirements at different growth stages. In spring, new shoots and new roots begin to grow, and the plant is in an active growth period, requiring more water, so it should be watered more. In summer on clear days, if sunlight is strong and temperature is high, the plant grows vigorously, internal water transpiration is fast, and air humidity is relatively low, so watering should be more frequent to keep the medium moist.

5.3 Fertilizer and water management for large seedlings

When no new roots are seen at the edge of the pot, first use foliar topdressing, and spray the leaves 2-3 times with 2000-fold diluted Cuiyun Vigor B1 liquid. After 20 d-25 d from repotting, after the plants grow new roots, water half-thoroughly once with 2000-3000-fold diluted 20-20-20 (N-P-K, containing complete nutritional elements; same below) quick-acting fertilizer solution. When new roots and new leaves are growing rapidly, water once every 7-10 days at a concentration of 1500-2000-fold.

5.4 Fertilizer and water management for promoting flower bud differentiation

One month before cooling-temperature flower forcing, stop applying fertilizers with relatively high nitrogen content, appropriately control water to regulate the plant's carbon-to-nitrogen ratio and improve maturity, and spray 1-2 times with 1000-fold diluted monopotassium phosphate solution. After going up the mountain, first water half-thoroughly 1-2 times with 2000-2500-fold diluted 9-45-15 quick-acting fertilizer to promote flower bud differentiation. After 25 d of cooling-temperature flower promotion, use 2500-fold diluted 10:30:20 quick-acting fertilizer to water half-thoroughly once every 10-15 days to promote continued flower bud differentiation and stalk emergence.

5.5 Fertilizer and water management from the flower stalk elongation stage to the flowering stage

At this stage, care should be taken that the medium must not be too dry. Especially in late autumn and early winter when the weather is dry, the sphagnum moss in the pot should be kept moist. When the sphagnum moss in the pot is slightly dry, use 2000-2500-fold diluted 15-20-25 quick-acting fertilizer to water once every 10-12 d. From bud emergence to the flowering stage, the amount of fertilizer applied should preferably be reduced, generally watering once every 10-15 days with 3000-fold diluted 15-20-25 quick-acting fertilizer. In winter, during the heating period, water evaporates quickly, so water should be applied in time to keep the medium moist.

6 Pest and disease control

6.1 Main diseases

6.1.1 Control for newly planted or repotted plants

On the day flask seedlings are planted, spray 4000-fold diluted 98% tetracycline hydrochloride solution or 3500-fold diluted 72% agricultural streptomycin sulfate solution to prevent soft rot, and spray once more after 1 week. On the day newly repotted medium seedlings are repotted, spray once with 3000-fold diluted 98% tetracycline hydrochloride solution or 3500-fold diluted 72% agricultural streptomycin sulfate solution for disease prevention. Do not water within 5 d after spraying, and spray once more after 7-10 d; afterward, spray once every 10-20 d in rotation to prevent bacterial or fungal diseases, using the same chemicals as for small seedling management.

6.1.2 Routine control during the seedling stage

Generally, spray once every two to three weeks for control. Use 4000-fold diluted 98% tetracycline hydrochloride solution and 3500-fold diluted 72% agricultural streptomycin sulfate solution alternately to control bacterial soft rot, and use 800-fold diluted 80% Haoshengling wettable powder and 1000-fold diluted 55% carbendazim wettable powder alternately to control fungal diseases.

6.2 Main insect pests

The main insect pests of Mantianhong include red spider mites, thrips, aphids, scale insects, whiteflies, and cotton leafworms. In pest control, in addition to clearing weeds and other pest hosts inside and outside the greenhouse, daily investigation should also be noted, yellow sticky boards can be used for trapping, and forecasting of pest occurrence should be carried out so as to discover and control them early.

6.2.1 Control of main insect pests during the seedling stage

In spring and summer, chive maggot larvae are prone to harming the roots of small seedlings, and noctuid larvae gnaw on the crown leaves. For chive maggot larvae, using yellow sticky boards for trapping and killing and replacing the yellow sticky boards in time can effectively reduce the adult population, thereby achieving the purpose of reducing damage and control. For red spider mites, 3000-fold diluted 40% Limansi emulsifiable concentrate, 1000-fold diluted 20% dicofol emulsifiable concentrate, 3000-fold diluted 24.5% avermectin emulsifiable concentrate, 6000-fold diluted 2% abamectin, etc. can be used alternately for control; for noctuid larvae, 2000-fold diluted 20% Susa emulsifiable concentrate, 2000-fold diluted 20% Haoniandong emulsifiable concentrate, 3000-fold diluted potassium avermectin salt emulsifiable concentrate, etc. can be used alternately for spray control.

6.2.2 Pest control from flower forcing to the flowering stage

From flower forcing to the flowering stage of Mantianhong, 2000-fold diluted Meichu, or 6000-fold diluted Actara, or 6000-fold diluted 2% abamectin, or 2000-fold diluted 10% imidacloprid, etc. can be used to spray and kill mites, aphids, and scale insects. For flower stalk plants, spray 3000-fold diluted 40% Limansi or 2000-fold diluted 10% imidacloprid or 6000-fold diluted Actara to control mite damage, thrips, and aphids. In addition, when humidity is too high, Xunbao smoke agent can be used for space insecticidal and pest prevention.

That is all for today's content. Because the article is quite detailed, everyone is welcome to save and share it. For more wonderful flower cultivation tips, stay tuned to the Huinong website!

Pest and disease control methods for tropical orchids

Key cultivation techniques for large-scale greenhouse production of Cattleya

In recent years, in the flower and plant market, Cattleya, this variety of orchidaceous plant, has become increasingly popular. There are many colors, and it is loved by many young people. Today, let us learn together the techniques for large-scale greenhouse cultivation of Cattleya.

1 Introduction of Cattleya

Cattleya is native to tropical and a small portion of subtropical regions from Central America to South America. Generally speaking, most Cattleya popular on the market today are horticultural varieties bred through multiple generations of hybridization and selection, with stable traits and easy cultivation. For growers initially cultivating Cattleya, they should consider aspects such as Cattleya flowering period, flower shape, growth habits, and cultivation cost to select varieties whose flower color and flower shape conform to Chinese aesthetics, whose flowering period coincides with major domestic holidays, with good reflowering ability, strong disease resistance, and tolerance to cold and high temperatures (for native species, it is recommended to introduce artificially selected polyploid plants). At present, most Cattleya seedlings in mainstream orchid nurseries in China are introduced from Taiwan, China, which has the best cost performance, and few are introduced from Europe, America, and Japan. When introducing, attention should be paid to the original source of the seedlings and the habits of the parent plants, and attention should also be paid to issues such as whether there are pests and diseases.

2 Site planning

Cattleya is a perennial herbaceous plant, with bulbous or club-shaped pseudobulbs at the lower part, 1 to 3 leathery leaves at the top, and creeping stems that can spread in multiple directions. It takes 2 to 4 years from removal from the flask to flowering. Cattleya is an epiphytic plant, and its root system consists mostly of aerial roots. Compared with other tropical orchids, it is relatively light-loving and drought-tolerant, and slightly cold-tolerant. Its growing environment prefers warmth and humidity, brightness and ventilation, and a slightly acidic, breathable medium. Therefore, when choosing to build a greenhouse, one should choose a flat area with sufficient light, convenient transportation, ventilation, and power supply facilities. Generally, the basic equipment for a greenhouse for planting Cattleya needs two-way exhaust fans, equipped with a water curtain and multi-layer shade netting, and in winter there should be supplementary lighting and heating facilities. Seedling benches should be set up more than 1 m above the ground, with a mesh bench surface, on which seedling plug trays and containers can be placed. Some varieties can be grown by hanging.

3 Cultivation methods

3.1 Selection of medium and cultivation containers. Cattleya roots are aerial and prefer moisture, so a planting material with good air permeability and drainage should be selected. Most Cattleya on the market are grown using sphagnum moss. This method has low cost and fast growth, but the medium easily decays and clumps; a small number of flower companies use pure bark for planting. Plants grown by this method are robust, but the cost is relatively high; a mixed medium can also be self-prepared. The pH value of the medium should be controlled at 5.5-6.5, weakly acidic. It is generally bark mixed with orchid stone mixed with fired soil mixed with Xiantu, at a ratio of 1:1:1:1. In terms of selecting cultivation containers for Cattleya, the principles of light transmission, air permeability, sufficient drainage holes at the bottom, and not being too large should be satisfied as much as possible. Generally, clay pots are best, transparent nutrient cups are second, and plastic dishes are last. When planting, there should be more bottom padding, and deep planting must be avoided.

3.2 Temperature, humidity and light management. Although Cattleya is drought-tolerant and cold-tolerant, it likes a high-temperature and high-humidity environment. The suitable temperature during the seedling stage is about 25°C. During the large seedling growth period, the temperature can be controlled at 15-30°C. In winter, the room temperature needs to be controlled not lower than 15°C to prevent frost damage and failure to flower, and 2-3 h of supplementary light is needed every day; the humidity during the seedling stage should be controlled at about 80%, and humidity can be maintained by mist humidification, water curtain humidification, and spraying the ground to cool and humidify; during the mature seedling stage, humidity should be controlled at 60%-80%. Cattleya should have light controlled during the seedling stage. From spring to autumn, use shade netting with a shading rate of 60%-70% for shading. From large seedlings to the flowering stage, management is relatively extensive, and in summer 50% shade netting is sufficient.

3.3 Water and fertilizer management. The growth period of Cattleya is from spring to early autumn. Generally, sufficient water must be ensured at the beginning of the growth period. When new shoots sprout in spring and summer, attention should be paid to timely water supplementation. Generally, water should be applied when the medium surface looks dry (sphagnum moss once every 2-3 d; bark and mixed planting materials watered once each at 9:00 and 15:00 every day; same below). Water thoroughly each time, and try to maintain the two extremes of dry and wet in the medium; in autumn and winter, watering should be controlled (sphagnum moss once every 4-5 d; bark and mixed planting materials once every 2-3 d), keeping the pot soil moist. During the growth period, Cattleya should be fertilized lightly and frequently. Generally, a mixed controlled-release fertilizer with a nitrogen-phosphorus-potassium ratio of 1:1:1 is used. During the large seedling growth stage, apply 1.5 g each time, with topdressing once every 7-14 d; when entering the flowering stage, flowering-stage fertilizer with a relatively high phosphorus and potassium ratio should be used; after flowering, the frequency and amount of fertilization should be reduced. During the growth process, orchid-specific foliar fertilizer should be used in combination for supplementation, generally sprayed once every 7 d, with the ratio used according to the parameters provided by different brands.

3.4 Division propagation. After growing for 3-4 years following removal from the flask, Cattleya can be propagated by division. Generally, ensure each clump has 3-5 old pseudobulbs, and 1-2 new shoots are most likely to grow and flower. Note that any gardening tools that come into contact with Cattleya during division must be disinfected to prevent disease infection. Division should be carried out before April when new shoots have just sprouted. During division, care should be taken to cut off shriveled pseudobulbs, cut off old and rotten roots, remove weak shoots, and keep the most robust new shoots on the main stem. All wounds should be coated with sulfur powder for disinfection, and planting should be carried out after the wounds have dried. When planting, the new shoots should be planted near the center of the pot to ensure that the new plant has enough growing space. Large plants and long-stalk plants should be staked to prevent lodging. Cattleya should not be divided frequently or excessively, otherwise the flowering performance of the plant will be greatly weakened.

3.5 Pest and disease control. Common diseases of Cattleya include anthracnose, soft rot, southern blight, and viral disease, and common insect pests include scale insects, slugs, and red spider mites. During the cultivation stage, pest and disease control should focus on prevention. On ordinary days, it is recommended to spray 800-1000-fold diluted thiazine methidathion emulsifiable concentrate, generally about once every 7 d; every 7 d, combine with 2000-fold diluted 75% chlorothalonil wettable powder for control. During the flowering period, it is not recommended to treat pests and diseases with medication; manual removal of diseased parts can be recommended. For viral disease, there is only prevention. Generally, keeping the environment clean and ventilated, disinfecting tools thoroughly, disinfecting plants thoroughly, and introducing from regular disease-free sources is sufficient; once diseased plants are found, they should be burned and destroyed immediately, and surrounding plants should be isolated for observation.

3.6 Flowering period management. During the flowering period of Cattleya, attention should be paid to constant temperature and light and ventilation to ensure normal flower development and color development, and to prevent disease spots from affecting ornamental quality. Large-flowered, multi-flowered, and long-stalk varieties should be staked to prevent lodging. The flowering period of Cattleya can last 30-45 d, which is relatively short compared with other tropical orchids such as Phalaenopsis, so it is best to sell them out of the greenhouse when the first flower bud opens. The flowering period of Cattleya consumes a large amount of plant nutrients, so topdressing should be carried out about 7 d after the plant flowers, and when spraying the plant during the flowering period, try not to get water on the flowers to prevent diseases.

The above are the key points of Cattleya cultivation techniques. Everyone is welcome to continue following the Huinong website and learn more flower and plant cultivation techniques!