Thursday, August 28, 2008

AMALAN PENANAMAN UMUM - Melatih Tanaman & Cantasan / GENERAL CULTURAL PRACTICES - Training & Pruning

TRAINING AND PRUNING
In general greenhouse crops (tomatoes, peppers and cucumbers) are indeterminant (vining) types to take advantage of the vertical volume of the greenhouse.
*The plant vines are supported on vine twine by vine clips. The twine is wrapped around some sort of device from which it can be unwound (tomahook, bobbin, etc.). Plants are trained up the twine to the wires forming a “V” shape. As the plants grow up to the overhead support wire, the twine is unwound, the plants lowered and shifted one space – “LEANED AND LOWERED”.

Tomato vines should not be lowered more than 2 feet at a time OR another good way to tell, DO NOT lower the vine such that an 80 or higher degree bend is created in the vine near the floor. High angles promote stem cracking.
*Plants are trained to 1-3 stems by removing (pruning) side shoots or “suckers”. Tomatoes are trained to 1 stem (or 2 stems to replace a topped or broken neighbour or during a season of high light, i.e., Spring or early Summer).
Peppers are usually trained to 2 or 3 stems. Their stems are much more brittle than tomatoes and tend to snap if they are leaned and lowered. Cucumbers have traditionally been trained using such methods as the “V-cordon” or “umbrella”. However, they can also be trained to 1 stem like tomatoes.

*Side shoots or suckers are so named because they suck nutrients from the main plant. The process of removing suckers = “sucker pruning” or “suckering”.

*NEVER PRUNE SIDE SHOOTS WITHIN 2 INCHES OF THE TOP! It is too easy to remove the APICAL MERISTEM, the top growing point. If the apical meristem is removed or damaged (the plant is “topped”), a lower side shoot or even a sucker from a neighboring plant will need to be allowed to grow and take over as the apical meristem. This will take time and this plant will now be behind the others. Therefore, STUDY the top of the plant carefully, DETERMINE the location of the apical meristem, MOVE 2 inches down, THEN begin pruning!
*Extra growths may also occur on fruit clusters. These should be removed.
*Leaves: As the plants grow old leaves furthest from the apical meristem will begin to age or senesce = yellow spots appear due to the loss of chlorophyll. These leaves are no longer contributing as much to photosynthesis. These leaves should be removed – usually 3 leaves once a week. This is about the usual number of leaves that appear at the meristem per week.
The first three leaves will be removed when the plants reach 4-6 feet.
Leaves should be removed in the morning when the plants are “turgid” (full of water) so that they break off crisply. Leaves should be removed at the stem-petiole abscission zone – the bulbous point of attachment of the leaf petiole to the main stem. This abscission zone forms a clean break and seals quickly. If the leaf is “ripped” off, the damaged tissue could provide a point of entry for pathogens.
NOTE: Removing old, lower leaves also allows for air movement around the
lower part of the plant. This reduces humidity that can promote disease.
Also, certain insect pests tend to reproduce on lower leaves. Pruning
reduces their overall populations.

Watch these 2 videos on How To Prune Tomatoes:



Tuesday, August 19, 2008

Amalan Tanaman Umum - Jarak Pokok & Susun Atur Tanaman / General Cultural Practices - Plant Spacing & Crop Layout

Jarak Tanaman ditentukan oleh 2 faktor berikut:
1) Kehadiran cahaya kepada lindungan -
Tanaman mestilah dijarakkan cukup jauh dari sebarang objek untuk mendapat jumlah cahaya yang sampai kepada daunnya semaksima mungkin untuk kadar Fotosintesis yang paling optima.

2) Bekalan air & zat untuk akar -
Tanaman mestilah cukup jauh jaraknya untuk mendapatkan bekalan yang cukup untuk kedua - dua bahan ini.

* Jarak tanaman di rumah berpelindung adalah lebih dekat berbanding di atas tanah/batas. Contohnya, Tomato di atas tanah = 4000 - 5000 pokok/ekar
Tomato secara Hidroponik/Fertigasi = 10,000 - 11,000 pokok/ekar
Mengapa? Rumah lindungan berdiameter kecil dan akar tanaman yang ditanam secara hidroponik/fertigasi 'disuap'kan dengan bekalan air/zat yang cukup dan berkala. Oleh itu, tidak perlu mempunyai sistem perakaran yang besar.
Akar tanaman yang ditanam di atas tanah akan berkembang untuk mencari air & zat. Oleh itu pokok yang ditanam di atas tanah mestilah dijarakkan sejauh mungkin untuk mengelakkan persaingan dengan pokok bersebelahan. Oleh itu, pengairan titis/fertigasi membolehkan jarak yang lebih dekat.
*Contoh jarak tanaman Hidroponik:
  • Tomato = 2.5 – 3 pokok/meter persegi
  • Lada Benggala = 2.5 – 4 pokok/meter persegi
  • Timun = 1.25 – 3 pokok/meter persegi
  • Melon = 2.5 - 3 pokok/meter persegi
Susun atur tanaman di dalam rumah lindungan haruslah pada barisan yang cenderung tepat menghadap ke Utara & Selatan. Ini adalah penting kerana pada waktu siang, Matahari bergerak dari Timur ke Barat dan jika baris tanaman diatur menghadap arah Timur ke Barat, baris yang paling Selatan akan melindungi cahaya kepada baris tanaman di belakangnya.
Seringkali tomato ditanam di baris berkembar yang berjarak 5-6 kaki dengan 3 pokok untuk setiap polibeg 'bantal' (slab) sepanjang 1 meter. yang disusun sebelah menyebelah.



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Plant spacing is determined by two main factors:

1) The availability of light to the canopy - Plants must be far enough apart so that a maximum amount of light reaches the leaves for optimum photosynthesis.
2) The availability of water and nutrients to the roots - Plants must be far enough apart so that all plants have an optimum supply of these items.
*Plant spacing in “vining” greenhouse crops, including tomatoes, is much closer than for field crops.
Example: Field (bush) tomatoes = 4000 – 5000 plants/acre.
Hydroponic greenhouse tomatoes = 10,000 – 11,000 plants/acre.
*Why? A vine has a much smaller diameter than a bush, so they can be closer together and the leaves will still obtain optimum light for photosynthesis. The roots of a plant growing in hydroponics receives all the water and nutrients it requires. They are “spoon-fed” and do not have to grow large systems. The roots of a field grown plant will be more spread out as they search for water and nutrients in the soil matrix. Therefore, field grown plants must be positioned far enough apart to avoid competition of neighboring plants for water or nutrients. NOTE: Drip irrigation allows for closer spacing.
*Typical hydroponic plant spacing:
  • Tomatoes = 2.5 – 3 plants per square meter
  • Peppers = 2.5 – 4 plants per square meter
  • Cucumbers = 1.25 – 3 plants per square meter
  • Melon = 2.5 - 3 plants per square meter
*The typical layout of the greenhouse for vining vegetable crops is in rows tending approximately north and south. This is important because during the day the sun moves from east to west and if the rows were also set up east to west the southern most rows (in the
northern hemisphere) would shade the rows behind them. Typically, tomatoes are also grown in “double rows”. These double rows are usually 5-6 feet apart. With 3 plants per Rockwool slab (1 meter long each) or perlite bag (about 36”), sets of 2 slabs/bags are placed side by side. With 6 plants per slab/bag a single row of slabs/bags is used. Overhead support wires are set at least 2 feet apart.