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.

www.gerberaisrael.com gerbera1@zahav.net.il

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

productive bud

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

The leaves

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

active leaf

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

detached leaf

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.

Adventitious roots

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.

Br e

ed ing

co de

The Flowers

Variety - Province

Variety - Lorca

by botanical definition

The gerbera flower.is an

inflorescence

Flower bud as first seen at bottom of the .leavesAt this phase

.the flower stem is not visible

Stem elongation

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.

Stem tip

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

petal

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

male

females

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

Packing

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

Top

Bottom

Open tray, designed in Israel, for 30 gerbera flowers. Note - the side holes are touching the walls.

Top

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

Bunching

.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.

. Drops

A200cc / hourWithmicro drip irrigation e.g. 200cc / hour (A), more O2. is dissolved into the solution

Micro flow

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