2. PENGGALAK PERTUMBUHAN
• Kerap kali tanaman gagal menghasilkan buah yang optimum
walaupun mendapat bekalan nutrient yang betul. Kurang
keberkesanan fisiologi tumbuhan adalah punca kepada fenomena
ini.
• Penggalak pertumbuhan pokok adalah bahan yang digunakan untuk
mengatur pengambilan nutrient dan pertumbuhan tanaman.
Penggalak pertumbuhan ini memainkan peranan penting dakam
percambahan biji benih, meranumkan buah, memperkasa
pengambilan nutrient, menyemarak sistesis protin, memperkuat
ketahanan dan membantu keadaan runtunan, mengurangkan
keguguran bunga dan buah dan membantu tumbesaran pokok.
• Biasanya pengatur pertumbuhan pokok ialah auxins, gibberellins,
ethylene etc.. Permintaan kepada pilihan semulajadi sudah
bertambah.
3. Kesan Amino Acid Terhadap Pokok
• Keperluan Asid Amino dalam kuantiti secukupnya telah
diketahui lama bagi kaedah untuk menambahkan hasil
dan kualiti tanaman keseluruhannya.
• Amino Acid dibekalkan kepada pokok melalui serapan
tanah. Ia membantu microflora didalam tanah, lantas
menggalakan integrasi penyerapan nutrient.
• Amino Acid membantu pertambahan kepekatan klorofil
yang membawa kepada kesan fotosintesis yang lebih
sempurna. Ini akan menjadikan tanaman lebih hijau
pekat.
4. Kesan Asid Amino Kepada Tanaman
• Penggunaan Amino acid dalam kuantiti yang betul adalah kaedah
untuk menambah hasil tanaman dan kualiti pokok. Sugguhpun pokok
mempunyai kemampuan asas melakukan biosintesis bagi
menghasilkan asid amino yang diperlukan dari nitrogen, carbon,
oxygen and hydrogen, proses biokimia ini sangat komplek dan
memerlukan tenaga yang banyak.
• Dari itu, penggunaan amino asid seperti dari TaaVeeKun Super
membolehkan tumbuhan menjimatkan tenaga untuk proses ini,
dimana boleh didedikasikan untuk pertumbuhan yang lebih sempurna
semasa tahap pertumbuhan kritikal.
• Amino asid adalah ramuan asas dalam proses biosintesis protin dan
hampir 20 jenis asid amino terlibat dalan proses biosintesis ini. Kajian
mendapati asid amino boleh secara terus atau separa terlibat dalam
aktiviti fisiologi tumbuhan.
• Amino acid yang dibekalkan dalam bentuk cecair, menyerap kedalam
stomata tumbuhan atau melalui kawasan akar bila bercampur
dengan tanah. Ini akan turut meningkatkan micro flora, yang akan
membantu penyatu serapan nutrient.
5. Sifat Semulajadi Auxins
• Auxin adalah berasal dari perkataan auxien Greek bermaksud
tumbuh. Campuran kompoun akan dikelaskan sebagai auxins jika ia
bersifat menyebabkan pemanjangan sel mata pucuk pokok ataupun
berupa asid indoleacetic dalam aktiviti fisiologi.
• Auxins biasanya menyebabkan kesan sampingan selain dari
pemanjangan sel mata pucuk tetapi karektor ini dianggap kritikal
kepada semua auxins dan membantu pengistilahan hormone.
6. Functions of Auxin
•
The following are some of the responses that auxin is known to cause (Davies, 1995; Mauseth, 1991; Raven, 1992;
Salisbury and Ross, 1992).
• Stimulates cell elongation
• Stimulates cell division in the cambium and, in combination with cytokinins in tissue culture
• Stimulates differentiation of phloem and xylem
• Stimulates root initiation on stem cuttings and lateral root development in tissue culture
• Mediates the tropistic response of bending in response to gravity and light
• The auxin supply from the apical bud suppresses growth of lateral buds
• Delays leaf senescence
• Can inhibit or promote (via ethylene stimulation) leaf and fruit abscission
• Can induce fruit setting and growth in some plants
• Involved in assimilate movement toward auxin possibly by an effect on phloem transport
• Delays fruit ripening
• Promotes flowering in Bromeliads
• Stimulates growth of flower parts
• Promotes (via ethylene production) femaleness in dioecious flowers
• Stimulates the production of ethylene at high concentrations
7. Nature of Cytokinins
• Cytokinins are compounds with a structure resembling
adenine which promote cell division and have other
similar functions to kinetin. Kinetin was the first cytokinin
discovered and so named because of the compounds
ability to promote cytokinesis (cell division). Though it is
a natural compound, It is not made in plants, and is
therefore usually considered a "synthetic" cytokinin
(meaning that the hormone is synthesized somewhere
other than in a plant). The most common form of
naturally occurring cytokinin in plants today is called
zeatin which was isolated from corn (Zea mays).
8. Cytokinin Functions
A list of some of the known physiological effects caused by cytokinins are listed below.
The response will vary depending on the type of cytokinin and plant species (Davies,
1995; Mauseth, 1991; Raven, 1992; Salisbury and Ross, 1992).
•Stimulates cell division.
•Stimulates morphogenesis (shoot initiation/bud formation) in tissue culture.
•Stimulates the growth of lateral buds-release of apical dominance.
•Stimulates leaf expansion resulting from cell enlargement.
•May enhance stomatal opening in some species.
•Promotes the conversion of etioplasts into chloroplasts via stimulation of chlorophyll
synthesis.
9. The Nature of Gibberellins
• Unlike the classification of auxins which are classified on
the basis of function, gibberellins are classified on the
basis of structure as well as function. All gibberellins are
derived from the ent-gibberellane skeleton. The structure
of this skeleton derivative along with the structure of a
few of the active gibberellins are shown above. The
gibberellins are named GA1....GAn in order of discovery.
Gibberellic acid, which was the first gibberellin to be
structurally characterised , is GA3. There are currently
136 GAs identified from plants, fungi and bacteria
10. Functions of Gibberellins
• Active gibberellins show many physiological effects, each depending on the type of
gibberellin present as well as the species of plant. Some of the physiological
processes stimulated by gibberellins are outlined below (Davies, 1995; Mauseth,
1991; Raven, 1992; Salisbury and Ross, 1992).
• Stimulate stem elongation by stimulating cell division and elongation.
• Stimulates bolting/flowering in response to long days.
• Breaks seed dormancy in some plants which require stratification or light to induce
germination.
• Stimulates enzyme production (a-amylase) in germinating cereal grains for
mobilization of seed reserves.
• Induces maleness in dioecious flowers (sex expression).
• Can cause parthenocarpic (seedless) fruit development.
• Can delay senescence in leaves and citrus fruits.