Abutilon Bella (Abutilon hybridum)

Germination
Light is not needed for germination. Cover the seed with coarse vermiculite. Germination is quick, usually only 3 days.

Plug Production
Media
Use a well-drained, disease-free, soilless medium with a pH of 5.5 to 6.3 and a medium initial nutrient charge (EC 0.75 mmhos/cm with a 1:2 extraction).

Sowing
Cover the seed with coarse vermiculite.

Temperature
Germination: 72 to 75°F (22 to 24°C)
Cotyledon stage: 65 to 72°F (18 to 22°C)
True leaves: 65 to 70°F (18 to 21°C)
Hold plugs: 62 to 65°F (16 to 18°C) Germination is quick, usually only 3 days.

Light
Stage 1: Light is not needed for germination.
After germination: 1,000 to 2,500 f.c. (10,000 to 30,000 Lux).
Seedling maturity: Up to 5,000 f.c. (54,000 Lux) if temperature can be controlled.

Humidity
Maintain 95% relative humidity until cotyledons emerge.

Soil Moisture
Keep soil moisture high until radicle emergence, then reduce moisture levels after the radicle penetrates the medium. Do not allow the seedlings to wilt.

Fertilizer
At radicle emergence, apply 50 to 75 ppm N from 15-0-15. As cotyledons expand, increase to 100 to 150 ppm N.

Growth Regulators
Not needed.

Growing On to Finish
Media
Use a well-drained, disease-free, soilless medium with
a pH of 5.5 to 6.5 and a medium initial nutrient charge.

Temperature
Nights: 60 to 65°F (15 to 18°C)
Days: 65 to 70°F (18 to 21°C)
Temperatures below 60°F (15°C) may cause reduced growth or longer crop time.
Temperatures above 85°F (30°C) may cause flower bud abortion.

Light
Maintain light levels at 3,000 to 5,000 f.c (30,000 to 54,000 Lux). Higher light levels may cause foliage to droop. During shorter days and periods of lower light levels, supplemental light from HID lights will decrease time to flower.

Irrigation
Irrigate plants before they are wilted severely to avoid damage.

Fertilizer
Abutilon has a moderate fertilizer requirement. Fertilize every other irrigation at 150 ppm nitrogen. Use a fertilizer with most or all of the nitrogen in the nitrate form. High ammonium-form nitrogen will promote excessively large leaves that will hide the flowers. Maintain medium electrical conductivity around 1.0 mmhos/cm (using 1:2 extraction). Excessive fertilization will suppress flowering. Growing the plants too hungry will cause the foliage to turn a pale green and the leaves to look droopy.

Growth Regulators
The best height control and branching is achieved when the plants are spaced as soon as the foliage touches the sides of the pot. If grown pot-tight, apply a Bonzi spray at 5 ppm 2 to 3 weeks after transplant. Only 1 application should be needed.
When applying growth regulators, always follow the current manufacturer label instructions. In-house trials are recommended to determine the best rate for your growing location.

Pinching
Pinching is not needed. Best branching occurs when the plants are spaced as soon as the foliage touches the sides of the pot.

Crop Scheduling
Sow to transplant (400-cell plug tray): 3 to 5 weeks
Transplant to flower: 6 to 8 weeks at 65 to 70°F (18 to 21°C). Crop time can increase to 12 weeks from transplant to flower at low temperatures and low light.
Note: Time to flower is fastest with high light levels. Abutilon is not responsive to photoperiod.

Common Problems
Insects: Aphids, mites, thrips, whitefly.
Diseases: Rhizoctonia root and stem rot – dark brown or tan lesions often at the medium surface. Drench with Banrot, Terraclor, Terraguard or similar compound.
Pythium root rot – soft, brown, mushy roots. Drench with Subdue, Banrot, Truban or similar compound.
Botrytis blight – tan or brown leaf or flower spots followed by gray, fuzzy spores. Maintain good air circulation and reduced humidity during production. Remove dead or injured leaves or flowers. Apply preventative sprays such as Chipco 26019 or Daconil, or smoke with Exotherm Termil.
Chemical Phytotoxicity: Abutilon is sensitive to some pesticides containing hydrocarbon solvents, such as emulsifiable concentrates.