216 Glossary
The name ‘papaya’ also refers to the fruit of other Carica species, including
C. pubescens and C. stipulata, and their various hybrids.
Carpel: A single pistil in a female flower part containing several pistils.
Certification: Seed or stock verified to be true or lacking viruses.
Certified seed: Progeny of registered seed stock is the final stage in the expansion
programme and is certified with a metal seal and blue tag.
Chelating agent: An organic compound that keeps metals in water from combining
and also known as sequestering agents, which prevent metal buildup that
causes staining.
Chilling injury: Damage to certain crops, namely, papaya, banana, cucumber
and sweet potato, which results from exposure to cold but above-freezing
temperatures.
Chlorosis: The yellowing of plant tissue due to nutrient deficiencies or disease.
Chromosomes: Small structures in the nucleus of a cell that carry the genes. They
appear as thread or rod-shaped structures during metaphase. Each species
has a characteristic number of chromosomes.
Climacteric period: The period in the development of some plant parts that involves
a series of biochemical changes associated with the natural respiratory rise
and autocatalytic production of ethylene. The climacteric period consists of
the pre-climacteric, pre-climacteric minimum, climacteric rise, climacteric
peak and post-climacteric phases.
Clone: A group of individuals of common ancestry, which have been propagated
vegetatively (asexually), usually by cutting or natural multiplication of
bulbs or tubers.
Cold storage: A type of insulated storage utilising mechanical refrigeration to main-
tain a stable cold temperature for long-term storage.
Commercial hybrid: Refers to the first-generation F 1 of the hybrid planted for any
purpose.
Complete fertiliser: A fertiliser that contains nitrogen, phosphorus and potassium.
Complete flower: Flower composed of a short axis or receptacle from which arise
four sets of floral parts-sepals, petals, stamens and pistils.
Compost: Humus made by decomposing vegetative matter in a compost bin or pile.
Cover crop: A crop that is planted in the absence of the normal crop to control weeds
and add humus to the soil when it is ploughed in prior to regular planting.
Cross-pollination: The process in which pollen is transferred from an anther
(the upper part of the stamen in which pollen is produced) of one flower
to the stigma (the pollen-receiving site of the pistil) of a second flower of a
different cultivar.
Cultivar: A plant derived from a cultivated variety that has originated and persisted
under cultivation, not necessarily referable to a botanical species, and of
botanical or horticultural importance, requiring a name.
Cytoplasm: Main contents of a cell in which the nucleus and other bodies are located.
Damping off: Decay of young seedlings at the ground level following a fungal
attack.
Dioecious: This species having unisexual flowers and each sex confined to a sepa-
rate plant or having staminate and pistillate flowers on different plants of