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Glossary
of terms: MNOP
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| Macronutrient: |
any
element required in large quantities for growth such as the primary
nutrients N-P-K. |
| Mandibles: |
one
of a pair of the mouthparts of an insect used for crushing food.
Mean: the average of.
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| Medium: |
a substance in which plants can be grown, A medium can be liquid
or solid. It can contain all the necessary nutrients and trace elements
for normal growth, or these can be supplemented. |
| Metabolism: |
the sum total of chemical processes occurring in cells by which
energy is stored in molecules or released from molecules, life being
maintained by a balance between the rates of processes. |
| Meristem: |
a
region of a plant in which active cell division occurs. They are
located at the tip of the plant growth. |
| Micronutrients: |
any trace elements or compounds which include, S, Fe, Mn, B, Mo,
Zn, & Cu. |
| Mother
plant: |
female
plant growth for cuttings or cloning stock and kept in a perpetual
vegetative state. |
| Mycelium: |
the
total mass of hyphae of a fungus that constitutes the vegetative
body ( as opposed to a fruiting body). |
| Mylar: |
a
reflective sheeting material. |
| Necrosis: |
localised
death of a plant part. |
| NFT:
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abbreviation
for nutrient film technique. |
| Nodes: |
the
part of the plant stem where leaves are attached or may develop
from buds.
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| N.P.K
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Nitrogen, Phosporous, Potassium. |
| Nucleic
acid: |
a
molecule comprising a sequence of nucleotides forming a polynucleotide
chain. Nucleic acids act as the genetic material of cells and occur
as either DNA or RNA. |
| Nutriculture: |
another
term for hydroponics. |
| Osmosis: |
the movement of a solvent through a differentially permeable membrane
from a solution with high water concentration and low solute concentration
to one with a low water concentration and high solute concentration. |
| Ovipositor: |
an organ of female insects, usually present at the tip of the abdomen
through which the egg is laid. It is sometimes developed to enable
the piercing of tissues, particularly where eggs are laid inside
other insects, animals or plants. |
| Ovule: |
a
structure found in higher plants that contain an egg cell and develops
into a seed after fertilisation. |
| Oxidation: |
the
addition of oxygen to a substance to increase the proportion of
oxygen in its molecule. Oxidation can be achieved without oxygen
by the removal of hydrogen |
| Ozone
generator: |
a machine that generates ozone. |
| Palisade: |
or
also called mesophyll. The internal tissue of a plant leaf except
the vascular bundles. All mesophyll cells contain chloroplasts for
photosynthesis which lie close to the edge of the cell in order
to gain maximum light and gas supply. Mesophyll tissue contains
numerous intercellular spaces which communicate with the atmosphere
outside the leaf via the stomata. |
| Parenchyma
cells: |
these
are thin walled, general purpose plant cells that usually have a
packing function. |
| Passive: |
hydroponic
system that moves the nutrient solution passively through absorption
or capillary action. |
| Pathogen: |
any
organism that causes disease such as a virus, bacterium or fungus.
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| Peat: |
accumulation
of dead plant material formed in wet conditions in bogs or fens
in the absence of oxygen so that decomposition is incomplete. It
is usually acidic. |
| Pericyle: |
the
layer of plant cells between the endodermis and the phloem consisting
mainly of parenchyma which becomes meristematic to form lateral
roots. |
| Perlite: |
1)
sand or volcanic glass expanded by heat. It holds water and nutrients
on its many irregular surfaces. 2) mineral soil improver. |
| Petiole: |
the stalk of a leaf containing vascular tissue which connects with
the vascular bundles of the stem. The base of the petiole where
it joins the stem, may have small leaflike structures called stipules
and axillary buds. |
| Ph: |
a
measure of the hydrogen ion concentration in an aqueous solution
on a scale from 1-14, 1.0 being very acidic, 14 is highly alkaline
and 7.0 being neutral. Plants grow best in a range of 5.5 to 6.8. |
| Ph
tester: |
electronic
or chemical indicators used to determine the ph level in the growing
medium or water. |
| Phloem: |
a
transport tissue characterised by the presence of sieve tubes, companion
cells and phloem parenchyma cells found in the vascular bundles
of higher plants. Phloem functions in the transport of dissolved
organic substances e.g. sucrose by translocation. |
| Phosphor
coating: |
internal bulb coating that diffuses light and is responsible for
various colour outputs. |
| Phosphorous
(k): |
one of the three macro-nutrients that promotes root and flower growth. |
| Photometrics: |
the
study of light, particularly colour. |
| Photon: |
a
quantum of radiant energy with a wavelength in the visible range
of the electromagnetic spetrum. |
| Photoperiod:
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the
length of daylight as compared with the length of darkness in each
24 hour cycle. |
| Photosynthesis: |
the process by which plants convert carbon dioxide and water into
organic chemicals using the energy of light with the release of
oxygen. |
| Phototropism
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a
bending growth movement of parts of a plant in response to light
stimulus. The movement produced by unequal growth is due to differences
in auxin concentration. |
| Pistil
or carpel: |
the flask shaped female reproductive unit of a flower made up of
ovary, style and stigma. |
| Pith: |
core
of a dicotyledon stem and contains parenchyma cells which have s
storage function. |
| PK13/14: |
a specific bloom boost nutrient. |
| PPM: |
parts
per million. |
| Primary
nutrients: |
N-P-K. |
| Protoplasm: |
the
living contents of a cell, i.e. the cytoplasm & nucleus. |
| Pupate: |
an
apparently inactive phase between larvae and adult insect. |
| Pythium: |
fungal
disease. |
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