IAA |
- indoleacidic acid (IAA) is one of the plant
hormones called
auxins. IAA is most commonly used to stimulate the
growth of roots on cuttings. It is often applied as a
powder to the cut end of the fresh
cutting. |
IBA |
- indolebutyric acid (IBA) is one of the plant
hormones
called
auxins. IBA is most commonly used to stimulate
the growth of roots on cuttings.
It is often applied as a powder to the cut end of the
fresh cutting. |
imbricate |
- the overlapping in a sequence such as the scales in a
pine cone. |
inarching |
- method of grafting in which a plant which is still
attached to its own roots, is grafted to another another
plant. |
incubation period |
- the time between infection by a
pathogen and appearance
of symptoms on the plant. It may be affected by the ambient
temperature and moisture levels in the area. Most
fungal
infections are encouraged by warm, wet weather. |
|
|
indehiscent |
- applies to fruit which does not split open to release
its seeds upon ripening. See
dehiscent. |
indeterminate |
- this term most often refers to vines that just keep on
growing indefinitely. Some plants will grow to a certain
size and, when the flowers on the terminal end open,
growth stops. See
determinate. |
indexing |
- this is a technique used to determine the presence of
a transmissible disease, especially a
virus, in a plant.
Plants sold as disease free are often the result of
indexing. |
indicator plant |
- plant that reacts to a pathogen (such as a
virus) or
to an environmental factor with specific symptoms and is
used to identify pathogens or determine the effects of
environmental factors |
inert ingredients |
- the active ingredients of a
pesticide or the actual amount of
nitrogen,
phosphorus and
potassium in a bag of
fertilizer is only a fraction of the volume
(and weight) in the
container. The remainder of the liquid or granular
material is made up of "inert ingredients." These
ingredients such as clay particles may be added to provide enough volume in
fertilizers so that they may be spread more evenly around
the garden. In pesticides, the inert ingredients often
fall into that cloudy area called "trade secrets". They
may be chemicals that help a spray stick to the leaf or
spread over a surface better or water or... well, that
is a secret. At times, there have been human health
concerns raised about certain so-called inert ingredients in
pesticides. |
|
|
infection |
- process in which a pathogen enters,
invades, or penetrates and establishes a parasitic
relationship with a host plant. |
inflorescence |
- includes the flower stem (peduncle) and its branches
(pedicels) and the flower or flowers. There are many
different ways that flowers are arranged in an
inflorescence and that arrangement can help identify the
species of the plant. See flower. |
inflorescence
leaves |
- in addition to flowers, some inflorescences also have
leaves along the stem. In
hostas, certain
species or
cultivars have flat, leaf-like structures on the flower
stem. |
informal garden |
- this is a garden or flower beds and borders that are
meant to reflect a natural arrangement of plants.
Informal gardens consist of wide, sweeping curves and
flows of plants in irregular or rounded sweeps. See
formal garden. |
informal landscape plant |
- plants which generally fit best in an informal garden
often have flower types and colors that reflect those
found in natural settings. The may also be more likely
to have a medium to
coarse texture. See
formal landscape
plant. |
|
|
inoculate |
- (n: inoculation) to expose a plant to a micro-organism
i.e. inoculum. This may be an infectious organism such
as a fungal spore or virus that will cause a disease or
may be beneficial such as the bacteria that helps
members of the
Legume family extract
nitrogen from the
air.
See Mycorrhizae |
inoculum |
- See above. |
inorganic |
- generally something that is not part of a living
organism. We are all carbon based organisms so this
generally refers to mineral elements or compounds. See
organic. |
insect |
- refers to those six-legged creatures that crawl or fly
around our gardens. Spider mites have eight legs and,
therefore, are not
insects. |
insect growth regulator (IGR) |
- some insecticides kill
insects by blocking their
ability to change forms in their life cycles. Many
insects must lose their external skeleton (molt) as they
grow to replace it with a larger one. Growth regulators
may prevent this and the insect dies. |
|
|
insecticidal soap |
- one of the first "organic"
pesticides used to combat
insect problems in the garden. These are soap products
that are sprayed onto the body of insects causing the
waxy coating to melt and the insect to die of
dehydration. As stated, they must be applied onto the
insect. There is no carry over if they are just sprayed
onto leaves. Obviously, they are not toxic to other
organisms.
Care should be taken with soap products
since they will also melt the waxy cuticle on plants if
over applied. Also, plants with natural waxy coatings
such as
Colorado blue spruce
or blue leaved hostas will lose their color if soaps are
applied to them. |
insecticide |
- any word with the suffix, icide, is a killer of
something. insecticides are substances either natural or
synthetic in origin which are meant to cause the death of an
insect. |
instar |
- as many
insects go through the different stages of
their life, they need to sluff off (molt) their current
skin (exoskeleton) to be able to move up to the next
bigger size or to a new form. Each of these stages is
called an instar. Every insect has a specific number of
instars that it will go through between egg and adult. |
Integrated Pest Management (IPM) |
- a system of plant
management that uses a variety of strategies to
maintain plants in a healthy and vigorous state. For
pest control, cultural, biological, physical and
chemical techniques are always considered and not just
"spray and pray". Generally, the least toxic approach
that will provide acceptable control is used. More on
IPM |
internode |
- the part of a stem between two adjacent
nodes.
The length of the internode on woody plants is often an
indicator of the amount of growth that occurred a
particular growing season. |
interstem |
- normally, grafting involves uniting a
scion (stem or
bud) with a
rootstock (or stock) to form a new plant. Sometimes the
scion and the rootstock are not compatible with each
other and will result in a failed graft. In these
cases, success may be accomplished by putting a stem of
a third plant between the scion and the root stock. This interstem needs to be compatible with both the scion on
top and the rootstock below. |
interveinal |
- the area between the veins of a leaf. |
|
|
invasive |
- Invasive plants are those that tend to move around
freely and soon are found in places that are undesirable
from the gardener's point of view. They may move by
rhizomes beneath the ground or they scatter a lot of
seed around. There is a thin line between a
groundcover and an
invasive plant. Both have similar characteristics but,
depending on the site, they may be viewed very
differently. |
invertebrates |
- these are
animals that have no spine such as earthworms,
slugs,
nematodes. |
in vitro |
- literally means "in glass" but may also refer to any
artificial environment.
Tissue culture is, perhaps, the most common form of
in vitro plant production. |
involucre |
- a ring of bracts at the base
of an inflorescence in such plants as members of the
Asteracea (formerly Compositae) Family of
plants. |
involute |
- this term relates to flower petals or leaves whose
margins are rolled, bent or curled inward. See
revolute.
|
ion |
-
an electrically charged atom or group of atoms
that may be positive, as in cation (+)
or negative, anion (-) |
|
|