gerbera - practice & theory
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Gerbera: practice & theory
Dr. Yoseph Shoub
copyright by the author
In our gerbera breeding farm in Israel we breed gerbera varieties for countries with climate similar to yours. We develop advanced growing techniques for soil and for hydroponics, and we guide our growers via questions and answers. This lecture is part of our efforts to support the growers.
At several locations in different countries we hold varieties trials. We do it with the cooperation of our producers Selecta. www.selectaworld.com
The morphology of the gerbera The stemIncludes: 4 mature leaves 2 flowers 1 new productive bud 2 dormant buds
scheme of A gerbera branchbuilt of 4 stems
2 flowers stems
each stem is ~ 5 mm. long
on : each stem 4 mature leaves (1 - 4) 2 flowers stems(each one is ~ 700 mm. Long)
(4 Internodes of ~ 1.25 mm.)
1 new productive bud 2 dormant buds3 4 2 1
scars of 2 picked flowers old mature leaves (1 - 4)
Gerbera seedling *
`*Seedling: a plant originated from seed, used in the breeding process.
4 mature leaves
3 juvenile leaves short stem of ~3mm
Gerbera plantlets ready for planting. At this stage, all the leaves are juvenile leaves.
Reading the plant phenotype* helps to reach the right professional decisions.
Mature leaves at different ages
* The plant phenotypeis the unique form of a variety.
Active leaf Normal aged leaf, already .contributed its content
Changes in the minerals content, cut the leaf activity.
early changes in the minerals content
Same leaves, bottom side
Something is wrong ! What do we tend to assume ?
Regarding flowering The gerbera is: Self inductive plant. Flowering is not affected by the length of the day, nor by the temperature.
Gerbera seedling 6 weeks after replanting. A branch with 2 flowers and a new young stem.
A new young stem
A seedling 10 weeks after replanting, already has more than 2 stems.
What about leaves thinning and optimal leaves number?
Mature gerbera plants
The crownA live tissue of compressed stems
Scars of:detached flowers stems
exposed growing 3 centersview from above
As a perennial wild plant, more growing centers are developed and turn into semi-independent plants.
The crown Adventitious root Secondary rootsview from aside
Adventitious rootsare formed from the stem, and not from another root.
In the photo - Adventitious roots of Polygonum sp. which have been formed while the green stem was covered by a wet soil.
The rootsThe roots system of the gerbera, is consisted of :two roots types Soil surface*
A. Adventitious roots The main roots, formed only on young stems, close to the soil surface.
B. Secondary roots The white rootlets, formed only on the adventitious roots.
* The soil surface is a sensitive level, regarding temperatures, water holding, evaporation, drying up, EC, pH, etc.
The white rootlets supply Oxygenated water and minerals solution via the root tips and the root hairs.
"Let us grow roots, the flowers are the by-products"
(This is the whole practical truth)
Young root systemSecondary roots Adventitious root
In containers, the appearance of the outer white rootlets, reflects the situation of the roots inside.
Washed roots system of a gerbera plant .grown in container
Established roots system of an Israeli variety, in Ecuadorian soil.
Use a shovel, for uprooting the roots.
Continuity of growth in spite of the :Old crown Contaminated scars of flowers stems And water supply via rusty tissuessemi independent new branch
New roots are able to emerge from a healthy gerbera young stem, in spite of the older roots condition.
Variety - Province
Variety - Lorca
by botanical definition
The gerbera flower.is an
Flower bud as first seen at bottom of the .leavesAt this phase
.the flower stem is not visible
Stem elongation upwards starts at the base of the .young stem The flower bud grows .upwards
The elongation process of the stem is not .symmetric One side grows and elongates faster than the .other side This growth pattern is directing the flower head .downwards + +
As long as the flower head is
located among and under the leaves, the stem continues to grow in non-symmetric pattern.This kind of growth protects the flower head until it passes the leaves. Than the growth turns, the stem and the flower head will continue to grow upwards.
The flower head just passed the edges of the leaves.
Flower head among .the leaves
Maturation of the Flower-stem Or when not to harvest gerberas * Maturation (lignifications) of the gerbera flower stem, starts at the stems base, and continues upwards, following the stem elongation.
In our breeding program, we pay attention to such stem qualities as length, strength, early lignifications and longevity.
At the same time, downward lignifications at the stems tip, continues only a few centimeters .and than stops
As long as the elongation process continues, the elongation sites remains flexible.* * Do not harvest gerbera flowersstem base
At early stages, the petals develop in non symmetric pattern, and this is normal.
! Cross section of gerbera inflorescence, ready for harvest ! At least 2 full circles of ripen male flowers are seen
Female flowers, flower, bract female flower, malemale flowers
receptacle stem tip
Single type flowers
Ligulate female flower
Tubular flowers Male females Male female
Double type flowers All are ligulate flowers
Single type flower, Female stage. Not ready for harvest,the stamen are not yet visible.
Pistil and Stigma
Same flower two days later: Ready for harvest, .Male stage circles of male 2 .flowers are open
Stamen and pollen
Post harvest treatment - essential and simple:
saturation with.post harvest solution
Our varieties grown in soil - Ecuador
Leading lines for harvest: Harvest during the cool hours of the morning. Pick only mature lignified stems. Pick only when two circles of male flowers show their stamens. Cut the stem base and immerse immediately in post harvest solution. Transfer the flowers containers to cool packing area as soon as possible.
mature gerbera flowers packed for shipment 30
Open tray, designed in Israel, for 30 gerbera flowers. Note - the side holes are touching the walls.
Tray ready for packing, 2 trays packed in one container. 60 flowers per container.
30 packed flowers
The other side of the same tray
Essential preparations before packing
.Bunches of one tray, are laid beneath the second tray
The trays top is tied to the container head
The container is ready to be covered
Important Note Stems packed in the container, and laid horizontally during the storage and the shipment, will react, after the arrival, with active Curved growth.
active curved growth
Storing and shipping the packed gerbera containers, in upside-down position, helps to avoid the phenomena.
Fertigation = Irrigation with fertilizers5 Major questions about fertigation of intensive crops: When to irrigate How much to irrigate When to fertilize How much to fertilize Which fertilizers to use
A few words about the importance of water and Oxygen
Oxygen plays an important role in the life of plants as for all living things. The fact is that plants are able to use the vital Oxygen only when it is dissolved in water, and water, for the plants, is the only Oxygen supplier.
By irrigating, we are supplying Oxygen, water, and minerals, all needed for optimal growth and production.
Note the descending order of importance Oxygen, water, all the other minerals.
With higher oxygen rate in the soil solution ,the plants are able to absorb fertilizers without difficulty .even if the concentrations of the minerals are low
About 11 to 8 ppm O2 is almost the higher possibility rate for O2 to dissolve in water (at sea level), for temperatures of 12 27C (the optimal range for gerbera Growth).
.Stagnant water (reservoir water), contain less oxygen than fresh water Water of high temperatures (35 - 40C), contain less Oxygen than cool .water
Water surface and Oxygen availability
O2 molecules dissolve into the water, through the surface of the water. The greater the surface area of the irrigated water, the higher the amount of O2 dissolve in it.
Therefore drip irrigation systems increase the Oxygen rate in the soil solution, compare to other traditional irrigation systems. For the same reason, Micro drip irrigation systems are excellent Oxygen suppliers.
A200cc / hourWithmicro drip irrigation e.g. 200cc / hour (A), more O2. is dissolved into the solution
B2000cc / hourWith conventional dripping 2000cc / hour (B), less O2 is dissolved into the solution.
The above data is a result of the physical fact - that the total number of drops, for the same water volume, is greater with micro dripping, than the total number of