Efficient Cultivation Techniques for Potted Calla Lilies and Control of Major Pests and Diseases

Growing Techniques Jan 1, 1970 0 views

How do you cultivate potted calla lilies? Below, the editors at Huinong.com have compiled a set of key techniques for large-scale cultivation of potted calla lilies; friends who want to grow calla lilies can learn more.

I. Preliminary Preparation

To draw up a calla lily production plan, you must first have a reliable tuber supplier to provide superior-quality tubers; this is the prerequisite for cultivation. When venturing into calla lily production for the first time, if there is no carefully arranged plan, everything will be difficult. Calla lily cultivation requires advanced growing techniques and a reasonable plan, plus orderly sales channels, to ensure the successful operation of the cultivation plan. The second point is variety selection; you should understand the cultivation characteristics of different varieties and not choose based only on flower color.

Tuber suppliers should inform you of the cultivation characteristics of different varieties and tuber specifications, so that you can choose the appropriate cultivation time and suitable flower pots.

1. Purchase and Treatment of Tubers

At purchase, check whether calla lily tubers show signs of disease or rot. Infected tubers usually have an unpleasant odor and should be removed and destroyed promptly to prevent the spread of pathogens. Areas that came into contact with diseased tubers should also be thoroughly disinfected.

2. Forcing Cultivation

Treat tubers that are about to be planted with gibberellin and place them under greenhouse conditions at 18°C. Once young shoots emerge, they can be potted up. During forcing cultivation, keep the ambient temperature around the tubers at about 18°C, humidity at 80%-90%, and spray with a low concentration of gibberellin. After about 20 days, when new shoots appear, they can be transplanted into pots. According to variety characteristics and market demand, pots with a specification of 14-20 cm are usually chosen; generally, the larger the pot diameter, the larger the plant canopy.

3. Tuber Storage

Tubers that do not need to be planted immediately should be stored in a timely manner. Under cool environmental conditions, they can be stored for 8 months without losing viability. Generally, storage for only 1-2 months is needed, keeping the temperature below 10°C and humidity at 70%-80%, with attention to proper ventilation.

II. Cultivation Techniques

1. Selection of Growing Substrate

Calla lilies prefer a well-drained growing substrate. Commonly used substrates generally contain composted bark, leaves, perlite, vermiculite, coarse sand, etc. Try to avoid using very fine particles, as they affect drainage. A small amount of fertilizer should also be added to the substrate, along with growth regulators to promote root growth, and biological fungicides should be used to disinfect the entire substrate. In addition, the pH of the potting substrate should be controlled at 5.8-6.2; if the pH is low, a suitable amount of lime can be added to adjust it. At the same time, however, the soluble salt content in the substrate should be kept low. If the soluble salt content is too high, root tips may turn brown or dry up. Changes in substrate moisture can also severely damage the root system, preventing water and nutrient uptake, causing wilting, yellowing, tissue necrosis, or stunted plants, and it also increases the incidence of root rot. Therefore, the choice of growing substrate and adjustment of pH are very important.

2. Temperature

Temperature can be adjusted in three stages:

① Early bud stage. When buds are less than 5 cm high, about 20 days before potting up, keep the temperature between 17°C and 20°C, with no day-night temperature difference.

② Growth stage. From when buds are more than 5 cm high until early flowering, keep daytime temperature at 16°C-24°C and nighttime temperature at 13°C-16°C. The size of the day-night temperature difference directly affects plant height; within a certain range, the greater the temperature difference, the greater the plant growth.

③ From early flowering to the sales period. Generally, keep the temperature the same as during the growth stage, but appropriately lowering the temperature can improve flower color quality and extend the flowering period.

3. Light

Light is closely related to temperature. Providing relatively intense light at different growth stages can promote calla lily flower coloration and strengthen the plants. When light is weak, plant vigor is poor and flower number is low; especially at the highest temperatures, increasing light intensity is crucial. However, excessively intense direct sunlight is unfavorable for calla lily growth, especially when planting in spring and summer, when appropriate shading should be provided to prevent sunburn. In locations with insufficient light, artificial supplemental lighting, appropriately lowering the temperature, and using growth regulators can improve flowering quality.

4. Humidity

Calla lilies have high requirements for greenhouse humidity, with relative humidity at 65%-75%. Below 50%, leaf or petal edges may become dehydrated and dry. Overwatering can lead to fungal diseases such as gray mold on the leaves. Properly adjusting temperature, shading, and controlling relative humidity are extremely important, and attention should be paid to maintaining ventilation.

5. Water and Fertilizer

Water has the greatest influence on calla lily growth and flowering, and a reasonable sprinkler irrigation system layout is crucial. Drip irrigation is the best choice; its advantages are moderate force, even water distribution, and accurate control of water volume. Calla lily tubers have strict water requirements. At the early growth stage, watering should be regular. When the plants are growing vigorously, water should be applied evenly according to the principle of drying and wetting alternately. Too much or too little water will reduce the plant's disease resistance.

The water requirement of calla lilies throughout the cultivation cycle goes from low to high. Just after potting up, slightly less water is needed. When true leaves appear and rapid growth begins, both the amount and frequency of watering should increase. Watering is best done in the morning; if water remains on the branches and leaves, fungal diseases can develop at night.

Calla lilies have relatively low fertilizer requirements. Generally, a nitrogen-phosphorus-potassium compound liquid fertilizer is used, with a content ratio of 4:1:3. At the same time, certain trace elements should also be applied, such as increasing the magnesium ion content in the growing substrate. It should be noted that calcium sulfate and ammonium bicarbonate bases are unfavorable for calla lily growth, so avoid mixing them in when selecting fertilizers.

6. Pest and Disease Control

At planting time, calla lilies must be thoroughly inspected and disinfected. If any plants are already infected with pathogens or disease, they should be removed promptly to prevent infection of other plants. Disinfect and sterilize the greenhouse environment at appropriate times to reduce the disease rate of the plants. During the growth period, the growth condition of the plants should also be checked frequently, and plants with abnormal leaves or roots should be handled promptly. The main disease of calla lilies is stem soft rot; if white fungus appears on the plants, it should be treated promptly. The disease can be prevented through water management, and fungicides can be used when necessary.

Although the calla lily production cycle is not long, storage and management during each growth stage differ considerably. During potted production, careful planning and reasonable arrangement are needed to obtain high-quality plants.

Potted Calla Lily Cultivation Techniques | Colored Calla Lily Growing Techniques | Botanical Characteristics of Calla Lily

Potted Calla Lily Cultivation Techniques | Colored Calla Lily Growing Techniques | Botanical Characteristics of Calla Lily --- Colored calla lily is a perennial herbaceous bulbous flower of the genus Zantedeschia in the Araceae family. Its flower shape is elegant and its colors are diverse. It is a new favorite in the flower market and can be cultivated as a cut flower and pot flower.

Botanical Characteristics of Potted Calla Lily

The leaves of colored calla lily are basal, entire, and emerald green. Some varieties have white spots on the leaves, and the petiole length is more than twice the leaf blade. The flower stalk rises above the leaves, the spadix is yellow, and the spathe can be white, yellow, pink, red, or purple, resembling a horseshoe shape; the fruit is fleshy.

Preliminary Preparation for Potted Calla Lily

Tubers. Colored calla lily tubers are propagated by seeds or daughter tubers. The bulb growth lifespan is 4 years. For potted tubers, select two-year-old cut flower bulbs that have not been harvested; the mother bulb has 6 to 9 daughter tubers of one to two cm around it, which is the best quality. Three-year-old tubers have been harvested for one season of cut flowers, have weaker growth, and the wounds produced by cut flower harvesting are prone to pathogen infection, so the incidence of bulb soft rot during cultivation is relatively high.

Treating tubers with gibberellin plus fungicide can increase flower number and prevent and control soft rot. Generally speaking, the number of flowers from gibberellin-treated tubers is twice that of untreated tubers. In addition, gibberellin slightly increases plant height, slightly reduces leaf width, and can soften tissues.

A backpack sprayer can be used to spray gibberellin and fungicide. Avoid soaking tubers in the solution to reduce the spread of pathogens. The solution is prepared as follows: add 20 ml of 37.5% copper hydroxide solution per liter of clean water, plus 125 ppm gibberellin. Adding a certain amount of copper-based disinfectant to the gibberellin solution helps control the spread of pathogens and reduces soft rot. After the solution is mixed, it must not be left standing; the solution must be stirred to prevent precipitation. Tubers should be air-dried, not dried with a fan.

After growers receive the tubers, they should open the packaging immediately, remove tubers infected with soft rot, and then wash their hands to avoid spreading bacteria to other healthy tubers. If it is green mold or black mold, it does not matter. Place the tubers in a well-ventilated tray below 18°C and plant them two or three days later; this allows wounds produced during transport to heal before planting. If storage lasts as long as 6 weeks or more, place them in a dark, cool, ventilated place, such as a warehouse at 10°C and 80% relative humidity. During storage, place the tubers with the sprouting side facing down, in a single layer in plastic crates.

Containers. Choose 12 cm to 20 cm tall plastic pots, which help the substrate drain and breathe. Plant one or two tubers per pot.

Substrate. The growing substrate for colored calla lily is very important. The substrate should be clean, have good permeability, a pH between 6 and 6.5, and an EC value below 0.5. Colored calla lily rooting dislikes high-salt substrates, and the optimal porosity is 20%±5%. Use 30% to 50% coarse-grade peat moss, mixed with large-particle perlite, coarse sand, fir bark, pumice, or slag, etc. Because pine bark is incompatible with paclobutrazol, use it cautiously or avoid it. Coarse sand can stabilize the flower pot and make it less likely to tip over. Gypsum or lime not only helps balance pH but also provides calcium beneficial for healthy plant growth.

The recommended substrate formula is as follows: 5 parts coarse peat moss, 2 parts perlite, 2 parts 3.2 mm to 6.4 mm fir bark, 1 part coarse sand. Coconut coir and coconut husk fiber are high-quality salt-free substrate mixing materials; in cut flower cultivation, they can improve flower and stem quality, but when growing potted plants they increase the disease incidence of tubers. Therefore, coconut coir is not recommended as a potted substrate for colored calla lily.

When potting, place the tuber with the bud eye facing up and the rounded side facing down. The roots of colored calla lily grow from around the bud eye on the upper part of the corm, so pay attention to proper planting depth. The tuber should be covered with 2.5 cm to 3.8 cm of substrate. If the corm is covered too shallowly, the roots will be exposed above the soil and are easily threatened by light and dry air; if the corm is exposed above the pot soil surface, new roots will have difficulty growing.

After potting, water thoroughly with clean water, place on a germination cart, and sprout in a germination room or small greenhouse compartment, maintaining the temperature at 22°C. This helps ensure uniform germination and reduces heating costs. After about 6 days of sprouting, when 50% of the pot flowers show sprouts, they can be moved out of the germination room, or moved out in two batches. If sprouting in the greenhouse, shade netting should be used to prevent excessively high temperatures.

Growth Period Management of Potted Calla Lily

In the first stage, to prevent and control diseases, drench the roots with a four-in-one fungicide solution on the 4th day after potting. The four-in-one fungicide solution includes 4 to 8 ml per 100 L of metalaxyl-M, 98 g per 100 L of fosetyl-aluminum, 30 g per 100 L of azoxystrobin, and 60 g to 120 g per 100 L of streptomycin sulfate.

From potting up until seedlings are 2.5 cm to 7.5 cm tall, during the period of 12 days to 25 days, maintain daytime temperature at 24°C and nighttime temperature at 18°C to 19°C. In early winter production, appropriate heating can improve plant vigor and growth. After seedlings have grown for 6 days to 10 days and reached a height of 1.25 cm to 5 cm, drench the roots with paclobutrazol at 6 ppm to 8 ppm. Do not apply paclobutrazol to small-flowered dwarf varieties; use a lower concentration for compact varieties; for tall, vigorous varieties suitable for large pot flowers and cut flowers, drench the roots twice at a higher concentration. If tuber germination and growth are uneven, first drench the pots whose sprouts have reached the required height and mark them; after the pots whose sprouts have not reached the height meet the standard, drench them as well.

The second stage begins about one week after sprouting, or from the first paclobutrazol root drench, until the leaves unfold. Depending on the variety, this should be 14 days to 28 days or 50 days. Maintain 21°C to 24°C during the day and 12°C to 15°C at night. Cool nights reduce plant height and delay production time.

In the third stage, flower buds begin to grow and color. Depending on the season and conditions, this is roughly from the 50th day to the 75th day; maintain daytime temperature at 18°C and nighttime temperature at 10°C to 13°C. In the second and third stages, if light is insufficient or paclobutrazol root drenching has not been used, the temperature can be lowered by 1°C to 2°C. This low temperature can improve the plant's growth habit and reduce the amount of paclobutrazol used, but it will prolong the growth period. It is worth noting that when the temperature is 10°C or slightly below 10°C, calla lilies stop growing, which can delay their flowering period and postpone marketing.

Negative temperature difference or morning cold stimulation. Two days to 5 days after the first use of paclobutrazol, cool the greenhouse by 3°C to 6°C in the early morning from 5 a.m. to 8 a.m. to create a negative temperature difference, that is, using the cold stimulation method. This can reduce the amount of paclobutrazol used and promote sturdy plants with a compact shape. Cold stimulation technology will not prolong the forcing cultivation growth period of the plants.

The only way to accelerate calla lily flowering is to increase the average temperature. However, in a warm climate, especially under low light, plants will become leggy, and in severe cases the leaves and flower buds will droop. In the early growth stage, if pale yellow leaves appear, it is usually caused by excessively high temperature, so it is best to advance the planting time. Low temperature will slow plant growth, and this is better than planting later and increasing the temperature in the second and third stages.

Light. Colored calla lily growth requires sufficient light, preferably controlled at 5,000 to 50,000 Lux, and it is not sensitive to photoperiod. Many flower growers place colored calla lilies the way they place bromeliads and anthuriums, too crowded, resulting in poor ventilation and light transmission, which leads to leggy, weak pot flowers. The placement density of colored calla lilies on the bench should be such that leaves of neighboring plants do not touch each other and there is a slight gap. In winter, temperatures in the Yangtze River basin are low and there is much rainy weather. Plastic film greenhouses should be re-covered with new film, and fixed inner second-layer film should not be used. During the day, the inner second-layer film should be opened to ensure sufficient light.

Humidity and ventilation. When air is not circulating, light is weak, or plants are crowded, excessively high humidity and growth environments that are too hot or too cold can cause diseases of leaves and roots. For production of Chinese New Year flowers, turn on internal circulation fans overnight to create horizontal airflow in the greenhouse and reduce humidity. Guttation at leaf tips or water droplets hanging on leaves can induce bacterial rot. It is worth noting that an excessively dry environment will make leaves narrower, affect plant vigor and even the number of flower buds, and ultimately affect product quality.

Water. Use a water source that is clean, pathogen-free, and has an EC value below 1.5, which is beneficial for healthy plant growth. Water supplies with high salinity or other problems need water treatment before use.

Watering depends on the season, temperature, and the water-holding capacity of the substrate. Keep the pot soil moist and avoid excessive wetness or dryness. After the first root drench with the four-in-one preventive fungicide, water lightly until the leaves unfold, and perform the second fungicide root drench at 14 days to 21 days. Avoid water accumulation in the pot soil, otherwise diseases spread easily. When applying slow-release fertilizer under warm conditions, alternating extreme drought and excessive moisture will damage the root system and greatly increase the possibility of plant infection by pathogens.

If the pot soil is too dry, flower buds will wither. Water sufficiently and thoroughly; water seeping from the bottom of the pot can carry away excessive salts accumulated in the pot soil. Avoid tidal irrigation and sub-irrigation from the bottom to prevent the spread of diseases. Long-term excessive wetness of the pot soil will cause moss to grow on the surface, which is unfavorable for calla lily disease management.

Fertilizer. The ideal initial fertilization is mixing 15-3-15 slow-release fertilizer into the substrate, with trace elements added if possible. Keep the pot soil moist, with an EC value between 1.5 and 2.0, and avoid exceeding 2.5. Do not use ammoniacal nitrogen. It is recommended to use a prepared liquid fertilizer at a constant 100 ppm to 150 ppm, with trace elements added. Under weak light or poor growing conditions, increase the fertilizer concentration: if fertilizing once a week, use a 100 ppm fertilizer; if once every two weeks, use a 200 ppm fertilizer; if fertilizing infrequently, use a 300 ppm fertilizer. You can add 1.5 g of 15-3-15 slow-release fertilizer to each 15 cm flower pot. If the pot soil is too dry, the temperature exceeds 25°C, and the slow-release fertilizer has been present for more than 30 days, fertilizer damage can occur, causing salt burn at leaf edges. Adding 1.78 kg of lime and dolomite per cubic meter of substrate can provide calcium for the plants and increase disease resistance. To make leaf color darker, add 46.9 ml of chelated iron to 100 L of water to make a solution, and spray weekly after the leaves unfold. The use of paclobutrazol and lower temperatures can also make leaf color darker.

To increase ventilation and light transmission for large-leaf varieties, reduce the nitrogen concentration in the fertilizer and increase phosphorus. Using 10-30-20 slow-release fertilizer can make plants grow sturdier and produce smaller, complete leaves, and can increase flower number.

In the last 6 weeks of the growth period, water thoroughly with clean water three to five times. This can clean the leaf surface and prevent salt accumulation in the pot soil from burning the root system.

Plant growth regulation. Paclobutrazol is the most effective growth regulator for calla lilies. When colored calla lily shoots grow to 1.25 cm to 5 cm high, apply paclobutrazol for the first time. The pot soil must be moist, preferably one or two days after fertilizing or after the second fungicide root drench of the pot soil. The second paclobutrazol application is usually 6 days to 10 days after the first use. Using low concentrations of paclobutrazol (6 ppm to 10 ppm) in two applications is more effective than spraying a higher-concentration solution all at once. It is recommended to spray 177 ml per 15 cm pot and 118 ml per 11 cm pot. Using too much paclobutrazol will cause the plant shape to become stunted, reduce flower number, and delay the flowering period. Correct use of paclobutrazol can greatly improve the quality of finished flowers and facilitate long-distance transport.

Do not use chlormequat on small-flowered varieties with narrow leaves. Large-flowered varieties can be root-drenched twice with 8 ppm paclobutrazol; tall cut flower varieties can be root-drenched two or three times with 10 ppm paclobutrazol.

In addition to concentration, many factors affect the effectiveness of paclobutrazol, such as weak light or short-day conditions, excessively high or low temperature, pot soil that is too dry, and watering immediately after spraying chlormequat. The use of paclobutrazol is not only a science but also an art. The same concentration will have different effects in different varieties, regions, and seasons. To accurately grasp the timing and concentration of spraying, you must keep detailed records of the environmental conditions at each spraying, the substrate moisture at the time of use, and the temperature and light conditions after use.

Pest and disease control. The main disease of colored calla lily is tuber soft rot caused by Erwinia bacteria, as well as banded leaf blight, etc. When yellow leaves appear on the plant, the producer only needs to remove the plastic pot to see that the roots along the corresponding pot wall below the yellow leaves appear water-soaked and transparent; these are diseased roots, while healthy roots are white.

Check the plants weekly for the following conditions: root browning, uneven growth, plant disease, weak roots, etc. Once disease is found, prevention and control should be carried out promptly. For pretreated corms, perform the first chemical root drench within two days to 6 days after the initial watering. If the tubers are not pretreated, perform the root drench within two or three days after the initial watering; the second root drench should be carried out 14 days to 21 days after the first root drench; the third root drench is carried out 21 days to 28 days after the second. All spraying and root drenching should be done in the morning, or early enough that all leaf surfaces can dry completely overnight.

For production of Chinese New Year flowers, because new leaves grow quickly and the greenhouse is closed and highly humid, young tissues are prone to bacterial diseases and need to be sprayed two or three times with copper-based products or azoxystrobin.

Controlling insect vectors such as fungus gnats, mosquitoes, small flies, and whiteflies is crucial because they can transmit bacteria and other diseases. Thrips can transmit leaf viruses such as impatiens necrotic spot and tomato spotted wilt; aphids can transmit taro mosaic virus. Generally speaking, calla lilies have a certain resistance to foliar spray phytotoxicity, and most insecticides can be used safely.

If plants are infected with soft rot, remove the diseased plants from the greenhouse promptly. In addition, greenhouse sanitation is crucial; do not grow multiple kinds of plants mixed together in one greenhouse.

Cultivation and Growing Techniques for Potted Colored Calla Lily

Colored calla lily is a perennial herbaceous bulbous flower of the genus Zantedeschia in the Araceae family. Its flower shape is elegant and its colors are diverse. It is a new favorite in the flower market and can be cultivated as a cut flower and pot flower.

Botanical Characteristics of Potted Calla Lily

The leaves of colored calla lily are basal, entire, and emerald green. Some varieties have white spots on the leaves, and the petiole length is more than twice the leaf blade; the flower stalk rises above the leaves, the spadix is yellow, and the spathe can be white, yellow, pink, red, or purple, resembling a horseshoe shape; the fruit is fleshy.