Four Star Culture Guide - 2019 - 44

OSTEOSPERMUM
Symphony

NUTRITION
pH: 5.8 - 6.2
EC: (2:1 extraction method) .6 - .9
Constant feeding at 150ppm - 200ppm nitrogen with a
fertilizer selected for grower's water quality and soil mix is
recommended.
TEMPERATURE
Rooting out: 65 - 72 F
Growing on: 55 - 68 F
Holding: 40 - 50 F
WATERING
Maintain moderate soil moisture. Allow the soil to cycle from
moist to dry. Avoid both severe dry downs/wilting and long
periods of wet soil, especially in cooler temperature, low light,
and high humidity conditions. Symphony Osteospermum
perform best if grown drier than many crops.
TIMING
4" - 5"/Grande™: 4 - 6 weeks with one 104 cell plant.
6" /1GL Royale™: 5 - 7 weeks with one 104 cell plant.
8": 7 - 9 weeks with one to two 104 cell plants.
10" - 12" Hanging Basket: 9 - 12 weeks with three to five
104 cell plants.
PLANTING
The 104 Liner plants should be planted into a well-drained soil
mix selected to match individual water quality and fertilizer
blends. Water in thoroughly without saturating the mix and
maintain a constant moderate soil moisture level for the first
seven to 10 days to establish new rooting. Pinching should
not be needed except in the case of taller material at time of
planting or a pinch on plants for larger containers. This pinch
can be given for larger containers, usually three to four weeks
after planting.

LIGHT/LIGHTING
These plants should be grown in a high light area of the
greenhouse for optimal flowering and plant development.
Symphony Osteospermum flower early and lighting should
not be needed for regular season crops. Daylength extension
lighting of 14 to 16 hours total daylength can be helpful for early
finish crops.
GROWTH REGULATORS
Moisture management and cooler growing alone are effective
methods of controlling growth. Not only does growing
Symphonys "on the dry side" produce the healthiest plants,
it also produces fuller and more compact plants. A light spray
application of 5ppm - 10ppm Sumagic® (uniconazole) or a
1ppm Bonzi® (paclobutrazol) drench can be applied, as needed.
Watch for the "softening" look and lighter green appearance
of new growth as an indication for PGR treatment needs. In
more northern areas, the lower rates should be used as a
starting base, while in more southern areas, the higher rates
will probably be needed. Other materials such as Topflor®
(flurprimidol) and Piccolo® (paclobutrazol) can be used at rates
that correspond with the degree of treatment recommended for
Sumagic or Bonzi.
Watering practices, weather and greenhouse
environment can greatly affect plant growth and
performance.
PEST and DISEASE MANAGEMENT
Proper temperature, light levels, air movement, humidity
control and water management will eliminate most disease
issues. Avoid darker, warmer and more humid areas with poor
air movement. A broad spectrum fungicide such as Banrot®
(etridiazole plus thiophanate-methyl) can be helpful when
applied at transplant, if desired. Scout for Botrytis and consider
a follow-up preventative fungicide application if pinching or
trimming plants. Also scout for any plant "melting." This soft rot
is usually a sign of overwatering and poor growing conditions.
Medallion® (fludioxonil), Pageant® (pyraclostrobin + boscalid)
or Cease® (Bacillus stubtilis) are effective to minimize spread
of the soft rot. Leaf burn and spotting from the use of copperbased fungicides are a concern. Thrip can also be a concern and
crops should be scouted on a regular basis.

Four Star Greenhouse I www.pwfourstar.com I 734-654-6420
44

The rates and chemicals listed are based on our southeast Michigan growing conditions, and are not recommended for nationwide application.
Please adjust the rates and spray applications to your location and facility.

http://www.pwfourstar.com

Four Star Culture Guide - 2019

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