Glossary 221
Nodule: Round bacteria-filled swellings on the roots of legume plants.
Nomenclature: The study of naming plants including spelling and format.
NPK: Nitrogen, phosphorous and potash are three main food elements necessary
for plant life. Nitrogen is required for foliage and growth, phosphorous for
flower and potash for roots.
Nutrient: A chemical required by a plant for growth.
Objectionable weed: Weeds whose seeds are difficult to be separated once mixed
with crop seed or which are poisonous or injurious or are having a smothering
effect on the main crop or are difficult to eradicate once established or are
having a high multiplication ratio thus making their spread quick.
Off type (rogue): Plant that does not conform to the varietal characteristics described
by the breeder. To designate a plant as an off type/rogue it is not necessary
to identify it as to variety.
Open pollinated: A plant that is pollinated by natural means, such as bees and other
insects, animals or the wind.
Organic matter: Materials rich in carbon of either plant or animal origin, which
exist in all stages of decomposition of soils.
Outcross: The mating of a hybrid with a third parent and produce an off-type plant
resulting from pollen of a different sort contaminating a seed field.
Ovary: The ovule-bearing part of a pistil. The female part of a flower containing
immature seeds (ovules).
Ovule: The egg-containing unit of an ovary, which becomes the seed after
fertilisation.
Pantothenic acid: It is considered as the ‘Anti-Stress’ vitamin because of its
important role in the functioning of the adrenal glands, which produce
hormones that help our bodies respond to stress. It plays an important
role in making haemoglobin, which transports oxygen throughout our
bodies. It is also helpful in detoxifying harmful chemicals such as herbi-
cides and insecticides.
Papain: An enzyme extracted from the papaya fruit that aids the digestion of protein
by breaking them down into smaller peptones. It has also been used to
prevent several disorders and diseases.
Pathogen: An organism that causes a plant disease.
Peatmoss: An organic soil additive from Sphagnum and related mosses. This is a
good water retentive addition to the soil but tends to add the acidity of the
soil pH.
Pedicel: The stalk of a flower or fruit when in a cluster or solitary.
Peduncle: The stalk of a flower cluster or a single flower when the flower is solitary,
or the remaining member of a reduced inflorescence.
Pentadria type flower: In severe cases, five antepetalous stamens are completely
transformed into carpels and the resulting flower resembles a female one
with a rounded ovary and free petals almost all along their length.
Perfect flower: A flower having both functional stamens and pistils or a plant with
both functioning male and female parts.
Pericarp: The fruit wall consisting of three distinct layers, namely, the exocarp, the
mesocarp and the endocarp.