GLOSSARY - Diseases of Fruit Crops in Australia - page 265

GLOSSARY

abiotic : non-living item or caused by non-living substance. calyx(-lyces) : the outer group of leaves surrounding a f lower, often

small and green-coloured.

acervulus(-uli) : saucer-shaped or cushion-like fungal fruiting body
that produces asexual conidia; characteristic of the genus
Colletotrichum .

cambium : thin layer of actively dividing cells located between the
xylem (water-conducting) and phloem (food-conducting) systems
in most vascular plants. The cambium is responsible for the growth
in the diameter of plants.

albedo : the white fibrous layer just below the coloured outer surface
of a citrus fruit.

cane : in grapevine, a mature woody shoot from leaf fall through its
second year.

anamorph : the asexual or imperfect state in the life cycle of a fungus
in which asexual spores, such as conidia, are produced.

canker : a dead, often sunken or cracked area on a stem, twig, limb
or trunk and surrounded by healthy tissue.

anthracnose : a plant disease having characteristic depressed spots
or lesions on leaves, stems or fruit; usually caused by fungi that
produce asexual spores in an acervulus. chlamydospore : a thick-walled resting spore of a fungus that allows

survival during adverse conditions.

ANVAS : Avocado Nursery Voluntary Accreditation Scheme,
introduced in 1978 in Australia. Its objective is to provide avocado
seedlings free from phytophthora and viroids.

chlorotic : yellowing of normally healthy (green) plant tissue due to
chlorophyll degradation or preventing chlorophyll production.

apothecium : an open-cup or saucer-shaped structure producing
ascospores.

chlorophyll : organic compound giving the green colour to plants
and used by them to make food during photosynthesis.

appressorium(-oria) : structure produced by a germinating fungal
spore, which adheres to the surface of the host and assists in the
penetration of surface cells by the fungus.

cleistotheciaum(-cia) : closed fruiting body (ascocarp)
characteristic of certain ascomycete fungi.

closterovirus : member of a group of f lexuous-rod plant viruses that
are mostly found only in the phloem system of plants. ascospore : a spore formed during the sexual stage in the life cycle

of certain fungi and carried in a microscopic structure called an
ascus.

coalesce : to run together, refers to smaller lesions joining and
becoming larger ones.

asexual reproduction : vegetative reproduction not involving gamete
formation or fusion. A common form of reproduction in fungi and
bacteria.

cocktails : sometimes called cukes, the result of poor pollination or
premature seed abortion in avocado.

conidium(-dia) : a fungal spore produced during the non-sexual
stage of the life cycle.

bacterium(-eria) : a single-celled microorganism lacking
chlorophyll and capable of extremely rapid reproduction.

corm : a short, swollen underground stem.

bark : the plant tissue outside the cambium in vascular plants.

crown : a shortened stem with leaves and axillary buds.

biofumigant : a fumigant with properties derived from a biological
source. damping-off : rapid death of germinating seed or seedlings before or

after emergence.

biotroph : an organism that feeds and lives on other living
organisms. degreening : in citrus, a process by which chlorophyll in fruit rind is

lost naturally when the ambient temperature drops or when fruit is
exposed to ethylene gas.

blight : a disease causing general and rapid death of leaves, f lowers or
stems.

deleafing : pruning older and diseased leaves from banana plants.

bloom : the stage of bud development when f flowering occurs.

desapping : the process of releasing sap from harvested fruit.

blotch : a disease causing large, irregular spots or blots on plant
parts. desuckering : removing young banana suckers from mother plants.

budwood : the part of the stem from which buds are cut for
propagation.

dieback : progressive death of roots, shoots or branches generally
starting at the tip.

button : disc at the base of citrus fruit where the stem joins the
fruit.

disinfestation : the process of eliminating insects from produce after
harvest.