Key Cultivation Techniques for Cut-Flower Anthurium in Solar Greenhouses

Cultivation Techniques for Cut-Flower Anthurium in Solar Greenhouses

Anthurium is native to the tropical rainforests of South America, and its unique flower shape and rich colors make it deeply loved by people. China began introducing cut-flower anthurium in the late 1970s, and it is now mainly concentrated in Shanghai, Yunnan, Guangzhou, Beijing and other places. In the late 1990s, commercial cultivation of cut-flower anthurium began in China. With changes in consumption trends and the strengthening of national purchasing power, society's demand for medium- and high-grade flowers increased, stimulating the expansion of anthurium production scale. In the regions of China where cut-flower anthurium is currently produced, most use intelligent greenhouses, which ordinary enterprises find difficult to afford and cannot participate in production. Using solar greenhouses to produce cut-flower anthurium has lower infrastructure cost investment than intelligent greenhouses and lower energy consumption, but the quality and yield of the cut flowers will not be affected.

Beijing is an important national center for flower consumption and scientific research, and the proportion of the flower industry in Beijing's agriculture is gradually increasing. According to surveys, in recent years the consumer groups in Beijing's flower market have a high awareness of cut-flower anthurium and relatively large demand, and the market is in a state of supply falling short of demand. Therefore, in order to meet the needs of market development, researching cut-flower anthurium solar greenhouse cultivation techniques can promote the development of the flower industry, increase farmer employment, and achieve obvious economic, social and environmental benefits.

1 Preparation of the Solar Greenhouse

1.1 Construction Requirements

The construction of the solar greenhouse should meet the requirements of the "Solar Greenhouse Construction Code."

1.2 Supporting Equipment Requirements

Circulation fans, water treatment equipment and drip irrigation equipment need to be installed in the greenhouse. For summer production of cut-flower anthurium, fans, wet curtains and automatic mist cooling equipment should be added, and in winter heating equipment should be added.

1.3 Sanitation Treatment

Before planting, clear weeds and debris inside and around the greenhouse. For insect control, use highly effective non-toxic or low-toxicity insecticides, such as 1% to 2% biological soap aqueous solution, or 40% phoxim emulsifiable concentrate 1.25‰ aqueous solution sprayed on the ground, seedbeds, drainage ditches, etc. For sterilization, broad-spectrum fungicidal smoke agents can be used for sealed fumigation for 12 to 24 h, such as 45% chlorothalonil smoke agent. During this period, entry of personnel is prohibited, and after completion, forced ventilation for 6 to 12 h is required.

2 Cultivation Method

The pot cultivation method should be selected, with flower pots 21 cm in diameter, planting 2 to 3 plants per pot. Place the flower pots on cultivation racks 50 to 70 cm high and 60 to 80 cm wide, with 1 drip irrigation emitter configured per pot, saving water and fertilizer. The passage width is 80 to 100 cm.

3 Preparation Before Planting

3.1 Substrate and Treatment

Oasis floral foam blocks should be selected as the substrate, with a substrate specification of cubes with side length 2 to 3 cm. They need to be repeatedly soaked or rinsed with irrigation water so that the pH value reaches 5.5 to 6.5. If the pH value is too low, lime can be added to adjust it, and after standing to allow full drainage, it is ready for use.

3.2 Seedling Treatment

After the seedlings arrive, open the packaging as soon as possible for ventilation and plant them in a timely manner. If they cannot be planted in time, they need to be placed in a cool, dry place at a temperature of 15 to 20°C, avoiding direct sunlight. Before planting, dip the roots with 600 to 800 times diluted 72.2% propamocarb hydrochloride aqueous solution.

4 Planting

4.1 Planting Time

Planting can be done throughout the year, and March to May or September to October should be selected.

4.2 Planting Density

The pot cultivation density is 14 to 21 plants/sq m.

4.3 Planting Depth

The planting depth should keep the root crown of the seedling level with the substrate surface.

5 Management After Planting

5.1 Environmental Control

After planting, water thoroughly in a timely manner. Within 15 d after planting, keep the leaf surface moist, and irrigation water can be sprayed onto the leaves. During this period, if the substrate surface becomes dry, a small amount of water can be applied until liquid seeps out from the bottom of the substrate. Within 15 d after planting, fertilization is prohibited; the temperature should be kept at 18 to 28°C, the relative humidity should be kept at 70% to 80%, and the light intensity should be 8,000 to 12,000 lx. After 15 d, operate according to the growth-period management method, with ventilation at least 1 time per day.

5.2 Pruning

After planting, if small flowers grow, remove them immediately. After 50 to 70 d from planting, begin pruning leaves, removing old leaves, and keeping 2 complete mature leaves per plant.

6 Growth Period Management

6.1 Environmental Control

6.1.1 Light The suitable light intensity is 12,000 to 20,000 lx, and the maximum light intensity should not be higher than 25,000 lx.

6.1.2 Temperature The temperature should be controlled at 18 to 28°C, with the minimum temperature not lower than 14°C and the maximum temperature not higher than 30°C.

6.1.3 Humidity The suitable relative humidity is 70% to 80%, with the minimum relative humidity not lower than 50% and the maximum relative humidity not higher than 90%.

6.2 Water and Fertilizer Management

6.2.1 Irrigation Water Quality Requirements The irrigation water quality should meet the requirements of the attached table; if it does not, water treatment is required.

Attached Table: Irrigation Water Quality Requirements

6.2.2 Nutrient Solution Preparation Method The nutrient solution is prepared as a 100-fold concentrated mother solution, divided into two tanks, A and B.

6.2.3 Vegetative Growth Stage For tank A, add 37.5 kg calcium nitrate, 5 kg magnesium nitrate and 3.75 kg 6% chelated iron (DTPA) to every 1,000 L of irrigation water; for tank B, add 25 kg potassium nitrate, 15 kg monopotassium phosphate, 20 kg magnesium sulfate, 34 g manganese sulfate, 150 g boron, 115 g zinc sulfate, 24 g copper sulfate and 24 g sodium molybdate to every 1,000 L of irrigation water.

6.2.4 Reproductive Growth Stage For tank A, add 50 kg calcium nitrate and 3.75 kg 6% chelated iron (DTPA) to every 1,000 L of irrigation water; for tank B, add 25 kg potassium nitrate, 15 kg monopotassium phosphate, 5 kg potassium sulfate, 25 kg magnesium sulfate, 34 g manganese sulfate, 150 g boron, 115 g zinc sulfate, 24 g copper sulfate and 24 g sodium molybdate to every 1,000 L of irrigation water.

6.2.5 Irrigation Method When the substrate is squeezed by hand and no liquid flows out, irrigation is needed, until liquid seeps out from the bottom of the substrate. The nutrient solution needs to be applied with water, once a day in spring, summer and autumn, once every 2 to 3 d in winter, and during the fertilization period, irrigate once separately with irrigation water every 30 d. If the greenhouse environment does not reach the suitable level of environmental control, the number of irrigations should be appropriately reduced, and if root rot occurs, the number of irrigations should also be reduced. During the growth period, detect the pH and EC values in the substrate once every 15 d, and if they do not meet the requirements, adjust them to the suitable level in a timely manner.

7 Common Diseases and Pests and Their Control

7.1 Diseases

7.1.1 Root Rot Main symptoms: leaf edges turn yellow and droop, and the roots turn brown and rot. Under adverse environmental conditions, such as dry substrate, large humidity fluctuations, or low temperatures, this disease is likely to occur. Control method: drench the roots with 72.2% propamocarb hydrochloride aqueous solution (concentration) 600 to 800 times diluted liquid, once a week for 3 consecutive weeks.

7.1.2 Leaf Spot Main symptoms: brown spots appear on the leaves, the centers of the spots dry up, and the edges are yellow. Control method: spray fungicidal preparations for control, such as 50% carbendazim wettable powder 600 to 800 times diluted liquid.

7.1.3 Bacterial Wilt Main symptoms: mostly occurs on leaves and flowers. The middle of the lesion is brown and the edges are yellow. In the early stage of pathogen infection, the spots are water-soaked, then form spots and spread to the entire leaf, causing plant death. The pathogen spreads through machinery and splashing water droplets. Control method: there is currently no specific drug for control. Prevention should be primary, regularly spraying agricultural streptomycin 72% soluble powder 4,000 to 5,000 times diluted liquid, and promptly destroying diseased plants when found.

7.2 Insect Pests

7.2.1 Red Spider Mites Main symptoms: they damage young leaves and buds, causing them to wither. Red spider mites pierce plant cells with their mouthparts to suck sap, causing the plant to lose green color and show silvery-white spots. When they damage flowers, brown spots appear on the spathe. Control method: use 1% to 2% biological soap diluted liquid, or 1.8% abamectin emulsifiable concentrate 3,000 to 4,000 times diluted liquid for control.

7.2.2 Thrips Main symptoms: thrips mainly pierce plant tissues with their mouthparts to suck sap, causing brown stripes to appear on leaves and flowers. When damage is severe, the leaves become brittle and deformed. Control method: hang blue sticky boards for monitoring and trapping, or spray 1.8% abamectin emulsifiable concentrate 3,000 to 4,000 times diluted liquid or 10% imidacloprid wettable powder 2,000 to 3,000 times diluted liquid.

8 Harvesting

8.1 Harvesting Time

Harvest when 2/3 to 3/4 of the spadix has changed color and the stamens are visible.

8.2 Harvesting Method

Pinch the middle of the stem with the thumb and index finger, and with the other hand hold a blade and cut diagonally upward along the end of the stem from bottom to top toward yourself, leaving about 3 cm of stem length on the plant. After harvesting, immediately place into a container filled with irrigation water and temporarily store in an environment at 15 to 18°C. During the harvesting process, sterilize the blade promptly with 75% alcohol. The container must be cleaned every day and disinfected every week.