Extremely small, one-celled organisims that don't have chlorophyll.
Bacterial soft rot
The electrical components that energize a high intensity bulb. (Typically a transformer or a capacitor)
An insect that eats bad flower and vegetable eating insects.
The process of removing clay and other impurities from phosphate rock to enhance the phosphorus content of the rock.
Capable of being decomposed by biological agents, especially bacteria.
Bloom Booster (Blossom Booster)
Fertilizer high in phosphorus (P) that increases flower yield.
When a plant prematurely begins the development of a flowering stalk, and, subsequently, seed.,
The function of this micronutrient is not well understood, but it is suspected that it might aid carbohydrate transport.
Any of various fungi of the genus Botrytis responsible for numerous diseases of fruits and vegetables; often referred to as bacterial soft rot or gray mold.
The ability of a substance to reduce shock and provide cushion against pH flucuations.
Buffers are solutions that have constant pH values and the ability to resist changes in the pH level. They are used to calibrate the pH measurement system (electrode and meter) Buffers are available with a wide range of pH values, and they come in both premixed liquid form or as convenient dry powder capsules.
Leaf tips that turn dark from excess fertilizer and salt burn.
Calcium is vital in all parts of plants to promote the translocation of carbohydrates, healthy cell wall structure, strong stems, membrane maintenance, and root structure development. Calcium is a macronutrient
Carbon Dioxide (CO2)
A colorless, odorless, tasteless gas in the air necessary for plant life. Occurs naturally in the atmosphere at .03%.
A phenomenon associated with surface tension and resulting in the elevation or depression of liquids in capillaries. This is similar to the manner in which plants seem to defy gravity when they transport liquid upwards from their roots.
Caton Exchange Capacity
A measure of soil's ability to hold positively charged nutrient ions for plant use.
Conductive factor (See Conductivity)
Combining nutrients in an atomic ring that is easy for plants to absorb.
This micronutrient is essential for photosynthesis, where it acts as an enyzme activator during the production of oxygen from water.
Any of a group of related green pigments found in photosynthetic cells that converts light energy into ATP and other forms of energy needed for biochemical processes; it is found in green plants, brown and red algae, and certain aerobic and anaerobic bacteria.
The condition of a sick plant with yellowing leaves due to inadequate formation of chlorophyll. Chlorosis is caused by a nutrient deficieny, usually iron or nitrogen; nutrient deficiencies are themselves often caused by a pH that is out of the acceptable range.
A plant produced through asexual reproduction including, but not limited to, cuttings, layering, and tissue culture.
A hydroponic system, like nutrient film technique (NFT) systems, that recirculates the nutrient solution.
Carbon-to-nitrogen ratio in soil. Provides a measure of the quality and rate of decomposition of organic matter. The lower the ration, the quicker the organic matter will break down, and release nutrients in forms available for plant uptake.
The relative color of light emitted by a lamp. An example is a piece of red hot iron emits a red glow which has a low color temperature. A piece of hite hot iron emits a glow with more blue light, which makes the color more white, and a higher color temperature. The unit of measure for color temperature is called "Kelvin" and is expressed in degrees Kelvin.
To soak new Rockwool in an acidic solution to lower the pH from 8.0 to 5.5
The scale used to measure the strength of nutrient solution. Pure water doesn't conduct any electricity but as you dissolve mineral salts in the water you increase Conductivity. More salts, stonger solution, higher Conductivity.
This micronutrient is an internal catalyst and acts as an electon carrier, it is also believed to play a role in nitrogen fixation.
The transfer of pollen from an anther of the flower of one plant to a stigma of the flower of another plant.
Disease that attacks young seedlings and cuttings, causing stems to rot at the base; overwatering is the main cause of damping-off.
A lack or shortage, especially of something essential to health; an insufficiency: a nutritional deficiency. When a plant's nutrient uptake is deficient it is evidenced by visual symptoms such as, but not limited to, changes in color, malformed leaves, and dying leaves.
The loss or removal of nitrogen or nitrogen compounds; specifically : reduction of nitrates or nitrites commonly by bacteria (as in soil) that usually results in the escape of nitrogen into the air. Often occurs in waterlogged soils.
Dioecious Of or relating to organisms, especially plants, having the male and female reproductive organs borne on separate individuals of the same species; sexually distinct.
The amount of dissolved solids, usually fertilizer salts, that are measured in water in parts per million.
A hydroponic method wherein air pressure from a small air pump is used to percolate nutrient solution out through a ring of feeder tubing which encircles the plant.
Drip System (Drip Emitter System) A very efficient watering system that employs a main hose with small water emitters. Water is metered out of the emitters, one drop at a time.
|Ebb and flow
The term "Ebb and Flow" simply means a method of irrigation that completely floods the growing media root zone, then lets the water drain away from the root zone, back to the reservoir. It is also called the "Flood and Drain" method by some growers.
Electrical conductivity See Conductivity
Having waters rich in mineral and organic nutrients that promote a proliferation of plant life, especially algae, which reduces the dissolved oxygen content and often causes the extinction of other organisms
One of several brand names/varieties of clay aggregate medium (also known as LECA for light expanded clay aggregate). It is a lightweight, porous substrate with excellent aeration. Because it does not really wick water effectively, Geolite and other LECA mediums are favorites in ebb-and-flow and drip hydroponic systems.
Inbred (True Breed)
The protective outer bulb or envelope of lamp.
A unit of measurement for expressing the heat or light given off by an object. At zero degrees Kelvin no molecules would be moving and no heat or light given off. Natural sunlight is 5500 degrees Kelvin. Light that has less blue will have a lower Kelvin temperature.
Measure of electricity used per hour; a 1000-watt HID uses one kilowatt in one hour
Open to change; adaptable, describes a soil nutrient which may become available for plant uptake.
Beneficial insects that prey on aphids
Dissolve or wash out soluble components of soil by heavy watering.
Washing of nutrients through the soil to a depth beyond the root zone of plants.
Leaf malformation due to over-watering, over fertilization, lack of magnesium, insect or fungus damage, or negative tropism.
Small immature leaf
Abnormally tall internode space, with sparse foliage. Legginess of a plant is usually caused by a lack of blue light or CO2. It can also be caused by too much nitrogen.
A series of growth stages through which a plant must pass in its natural lifetime; the stages for an annual plant are seed, seedling, vegetative, and floral.
A device that moves a lamp back and forth across or in a circle around the ceiling of a garden room to provide more even distribution of light.
Used in the form of dolomite or hydrated lime to raise and stabilize soil pH.
Chemically sensitive paper used for testing pH. The paper is chemically treated in such a way that when dipped into a water sample it will change color to indicate the pH level.
Organic soil mixture of crumbly clay, silt, and sand.
The amount of light emitted by a candle at a distance of 1 foot from the candle.
Lumens per Watt
The lumen output of a lamp, divided by the input wattage.
The unit of length equal to one billionth of a meter. It is used to measure the spectrum of light colors. Blue light has a shorter wavelength than red light
Parts Per Million (PPM)
The container in a hydroponic system which holds nutrient solution in reserve for use.
The process of removing minerals from water by pushing a solution through a filter that traps the solute on one side and allows the pure solvent to be obtained from the other side.
Inert, soilless growing medium consisting of woven, thin strand-like fibers made from molten volcanic rock and limestone, which is heated to over 2900 degrees farenheit, extruded, and formed into slabs, cubes, and blocks.
Soil which affects plant growth due to high levels of salinity. Normally associated with sodium choloride.
The measure of the ratio of change in osmotic pressure caused by different fertilizers. A fertilizer with a high salt index may cause damage to when applied near or directly to seeds.
Calcium (Ca) and magnesium are considered to be the secondary nutrients.
To apply granular fertilizer to the soil alongside a plant or row of plants during the growing season to stimulate them.
Soil where the structure has been affected by high concentrations of exchangable sodium.
The status of soil in regards to the amount and availability of essential nutrients.
Splitting the seasonal fertilizer requirement into a number of smaller applications. This technique is commonly used for nitrogen and potassium, which are subject to loss through leaching.
A stem or similar structure that supports a plant part such as a flower, flower cluster, or leaf. On a male flower it is the portion of the stamen that supports the anther.
The pollen-producing organ of a flower, usually consisting of a filament and an anther.
The state or condition of being free from microorganisms. In hydroponics it is essential that all materials being used are sterile to avoid contamination of the hydroponic system.
The receptive apex of the pistil of a flowe, on which pollen is deposited at in pollination.
The usually slender part of a pistil, situated between the ovary and the stigma.
Used in reference to a disease within the plant tissue, not intiated from the external cells. Also refers to materials and compounds which are taken up or absorbed by the plant and designed to fight disease (e.g. systemic fungicide).
Light with very short wave lengths, out of the visible spectrum past the blue-violet
|VAM (Vesicular sbuscular
A soil fungus that attacks the roots of some plants and assists in the uptake of phosphorus and other immobile nutrients
Mica which has been processed and expanded by heat. Vermiculite has excellent water retention qualities and is a good soil amendment and medium for rooting cuttings
The process by which certain soluble soil nutrients are changed from solid or aqueous forms to gaseous forms and are lost from the soil to the atmosphere.
|Watts per Square Foot
The wattage of a lamp, divided by the size of the coverage area.
Part of passive hydroponic system using a wick suspended in the nutrient solution. The nutrients pass up the wick and are absorbed by the medium and roots.
Any plant disease characterized by drooping and shriveling; usually caused by parasites attacking the roots.
Like copper and manganese, zinc is linked to chlorophyll synthesis.