biology of economic agriculture

1. Brassica
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2. Introduction
Brassica is a genus of plants in the
mustard family (Brassicaceae)
The members of the genus may be
collectively known either as
cabbages
mustards
Crops from this genus are
sometimes called cole crops
from the Latin caulis (= stem or cabbage)
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3. Introduction
This genus contains more important
agricultural and horticultural crops
It also includes a number of weeds
wild taxa
escapees from cultivation
It includes
over 30 wild species and hybrids
numerous additional cultivars and
hybrids of cultivated origin
Most: annuals or biennials
Some: small shrubs
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4. Uses
Food
Almost all parts of some species or
other have been developed for food
Root: swedes, turnips
Stems: kohlrabi
Leaves: cabbage, brussels sprouts
Flowers: cauliflower, broccoli
Seeds: mustard seed, oilseed rape
Some forms with white or purple
foliage or flowerheads, are also
sometimes grown for ornament.
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5. Use
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Medicine
Brassica provide
high amounts of vitamin C
soluble fiber
multiple nutrients with potent anti-cancer
properties:
3,3'-Diindolylmethane,
sulforaphane
selenium.
3,3'-Diindolylmethane
innate immune response system
anti-viral
anti-bacterial
anti-cancer activity.

6. Taxonomy
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Kingdom: Plantae – Plants
Subkingdom: Tracheobionta – Vascular plants
Superdivision: Spermatophyta – Seed plants
Division: Magnoliophyta – Flowering plants
Class: Magnoliopsida – Dicotyledons
Subclass: Dilleniidae Order Capparales
Family: Brassicaceae – Mustard family
Genus: Brassica L. – mustard

7. Taxonomy
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Species: Brassica alboglabra L.H. Bailey – Chinese kale
Species Brassica carinata A. Braun
Species Brassica chinensis L. – pak choi
Species Brassica cretica Lam. – mustard
Species Brassica elongata Ehrh. – elongated mustard
Species Brassica fruticulosa Cyr. – Mediterranean cabbage
Species Brassica juncea (L.) Czern. – India mustard

8. Species Brassica napus L. – rape
Variety Brassica napus L. var. napus – rape
Variety Brassica napus L. var. pabularia (DC.) Rchb. –
Siberian kale
Species Brassica narinosa L.H. Bailey – broadbeaked
mustard
Species Brassica nigra (L.) W.D.J. Koch – black mustard
Species Brassica parachinensis L.H. Bailey – false pak choi
Species Brassica perviridis (L.H. Bailey) L.H. Bailey – tender
green
Taxonomy
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9. Taxonomy
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Species Brassica oleracea L. – cabbage
Variety Brassica oleracea L. var. capitata L.
Variety Brassica oleracea L. var. botrytis L. –
broccoli
Variety Brassica oleracea L. var. costata DC. –
tronchuda cabbage
Variety Brassica oleracea L. var. gemmifera DC. –
brussels sprouts
Variety Brassica oleracea L. var. gongylodes L. –
kohlrabi
Variety Brassica oleracea L. var. italica Plenck –
sprouting broccoli

10. Taxonomy
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Species Brassica rapa L. – field mustard
Variety Brassica rapa L. var. amplexicaulis Tanaka
& Ono – field mustard
Variety Brassica rapa L. var. dichotoma (Roxb. ex
Fleming) Kitam. – toria
Variety Brassica rapa L. var. rapa – field mustard
Variety Brassica rapa L. var. silvestris (Lam.) Briggs
– colza
Variety Brassica rapa L. var. trilocularis (Roxb.)
Kitam. – yellow sarson

11. Taxonomy
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Species Brassica rupestris Raf. – mustard
Species Brassica ruvo L.H. Bailey – ruvo kale
Species Brassica septiceps (L.H. Bailey) L.H.
Bailey – seven top turnip
Species Brassica sisymbrioides (Fisch.)
Grossh. [excluded]
Species Brassica tournefortii Gouan – Asian
mustard

12. Triangle of U theory
Due to their agricultural importance,
Brassica plants have been the
subject of much scientific interest.
The close relationship between six
particularly important species is
described by the Triangle of U
theory.
Brassica carinata
B. juncea
B. oleracea
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B. napus
B. nigra
B. rapa

13. Triangle of U theory
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14. Brassica Genomes
AA (2n=2x=20): Brassica rapa (syn.
Brassica campestris)
Turnip
Chinese cabbage
BB (2n=2x=16): Brassica nigra
Black mustard
CC (2n=2x=18): Brassica oleracea
Cabbage
Kale
Broccoli
Brussels sprouts
cauliflower 14

15. Broccoli
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Broccoli was derived from a species
of wild Cabbage, B. oleracea.
This species has become so complex
that scientists have divided it into
several botanical groups
The Common Broccoli (Botrytis group)
was developed to have a dense, central
flowering head on a thick stem
Sprouting Broccoli (Italica group), also
known as Italian Broccoli and Asparagus
Broccoli, is wild looking and has loose,
leafy stems and edible flower shoots, but
no central head.

16. Botrytis group
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This is a biennial, grown as an annual.
It has grayish-green leaves and
succulent, edible stems, which support
large, compact heads of thickly
clustered flower buds.
Heads may be blue-green, purple-green
or green.
Examples:
Premium Crop
Purple Broccoli varieties
Green Duke
also exist
Green Comet
Romanesco.

17. Italica group
This Broccoli doesn't form a central
head.
Instead, it forms many slender,
flowering shoots from a central stem.
Both green and purple varieties exist.
Some prefer this Broccoli (sprouting
Broccoli) to the heading type because
it has a longer harvesting period.
Example: De Cicco
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18. Brussels Sprouts
The botanical name is B. oleracea
gemmifera.
The plants have an erect, central stem
Dozens of little "sprouts" that
resemble miniature cabbages
between the petioles of the leaves
If left on the plant they would develop
into flowering shoots.
Captain Marvel (early)
Prince Marvel (midseason);
Jade Cross E (a heavy producing late
cultivar).
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19. Cabbage
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The most familiar are the head Cabbages
(Capitata group): B. oleracea capitata,
which include
smooth green
red kinds
crinkly-leaved Savoys.
There are two kinds of Chinese Cabbages
(Pekinensis group):
Heading types, Pe-tsai (B. rapa, which either
have cylindrical or barrel-shaped heads;
non-heading types, or
Pak-choi (B. rapa, Chinensis group), have
loosely clustered leaves on succulent stems,
but form no compact, central head.

20. Cabbage
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Ornamental Cabbages (Acephala group): B.
Oleracea acephala, are cultivated for the sake
of their beautiful leaves.
Pekinensis group, Pe-tsai, - heading
This Chinese Cabbage has several popular
names including Pe-tsai, Celery Cabbage and
Napa Cabbage.
They come in many different shapes; the heads
may be long, slender and cylindrical, with dark
green tip leaves, such as Michihli types, or
short and barrel-shaped, with yellowish-green
or yellow leaves, as in Napa types.
The leaf petioles are broad and fleshy.

21. Chinensis group
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(Pak-choi - nonheading)
These Chinese Cabbages are great for
small gardens.
Other common names are Pak-choi, Bok
Choy, Chinese Mustard and Celery
Mustard.
The dark green leaves have a powdery
bloom and broad, white petioles that
are shingles at the base.
The inner leaves cluster, but do not
form a head.

22. Acephala group
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(Ornamental)
These have beautiful leaves that come
in cream, white, pink, purple, green and
lavender bicolor variations.
The outer leaves of a mature plant are
tough, but the central leaves make
colourful coleslaw and can be boiled.
You can use the leaves to line salad
plates or remove the center leaves from
young heads to make pretty "bowls" for
various fillings.

23. Cultivars
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Cabbage - (Capitata group)
Early: Golden Acre; Darkri.
Midseason: King Cole; Greenback;
Roundup; Blue Ribbon.
Late: Blue Boy; Rio Verde, Grand Slam.
Savoy: Savoy King.
Red Cabbages: Preko. (Pekinensis
group) Spring A-1; Jade Pagoda;
Tropical Delight; Michihli. (Chinensis
group) Joi Choi; Lei Choi.

24. Cauliflower
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The botanical name of this vegetable
is B. oleracea variety botrytis.
Cauliflower are the large, flat,
central clusters of flower buds called
curds. The inner leaves on some
kinds curve inwards to cover and
blanch the curd.
Cultivars:
Snow Crown
White Contessa
Alert.

25. Collards
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(Acephala Group - ornamental)
Collards have wide, smooth, blue-green
leaves.
The lower leaves hang down with
age and the upper or crown leaves
are usually cupped.
Collards are similar to it's relative,
Kale, but taste slightly different and
seem to be preferred across the
South.
Collards - Sugarhat; Catalogna.

26. Kale
(Acephala Group - ornamental)
Kale is like a nonheading Cabbage and differs
slightly from Collards in appearance and taste.
Most Kale varieties have upright, green to deep
blue-green leaves with fringed or wavy edges
and long petioles.
Ornamental, or flowering Kale is a pretty plant
with frilly leaves and open growth.
The leaves are beautifully colored and variegated
with purple, cream, white, or rose. This plant can
be eaten, but isn't bred for tenderness.
Kale - Dwarf Blue Curled Scotch; Winterbor.
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27. Kohlrabi
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This vegetable, also known as Turnip Cabbage
and Stem Turnip, is a close relative of Cabbage.
It grows from an erect stem that forms a
turnip-like swelling just above the surface of
the soil.
This edible swelling is often called a bulb. The
foliage grows from the bulb on long stems and
resembles the leaves of Cabbage.
Kohlrabi - Rapid is a good early variety. Grand
Duke is a midseason green hybrid. Purple
Danube is an improvement over the old Purple
Vienna.

28. Mustard
Mustard has several common names such as
Indian Mustard, Brown Mustard and Spinach
Mustard.
Mustard leaves are yellowish to medium green
and fairly wide.
When they are mature, the plants are large,
loose and open.
The White Mustard, B. alba, is a common weed.
The Black Mustard, B. nigra, is a tall annual that
is grown commercially for its seeds, which are
dried and ground to make the familiar condiment
mustard.
The Leaf Mustard is B. juncea and B. rapa is the
Tendergreen Mustard.
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29. Rape & Hanover Salad
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Some kinds of Rape, also called Colza, are
direct seeded from late summer through fall
for pasturing livestock.
Other varieties are grown to produce birdseed
or processed to make rape oil.
Some gardeners grow Rape to turn under as an
inexpensive green manure crop.
The large, rough plants have bristly, lyre- or
fiddle-shaped leaves with thick, clasping
petioles.
A relative of the forage Rape called Hanover
Salad (B. napa) has long been grown as a
forage and green manure crop in parts of the
South.

30. Turnip
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Varieties of Turnips are used
for their roots, their leaves,
or both.
The root may be white, white and
purple, or yellow.
The leaves are medium green and
rough.
They are tender when they are
young and ready to harvest 45 to 60
days after planting.

31. Turnip
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Varieties of Turnips are used for their
roots, their leaves, or both. The root
may be white, white and purple, or
yellow. The leaves are medium green
and rough. They are tender when they
are young and ready to harvest 45 to 60
days after planting.
Turnip
Just Right; All Top (the best grown for
leaves); Purple Top White Globe (best for its
roots); Ohno Scarlet; Gilfeather; Amber Ball.

32. Interspecific Breeding
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The interspecific breeding allowed
for the creation of three new species
of tetraploid Brassica (allotetraploid)
AABB (2n=4x=36): Brassica juncea
Indian mustard
AACC (2n=4x=38): Brassica napus
Rapeseed
rutabaga
BBCC (2n=4x=34): Brassica carinata
Ethiopian mustard

33. Pests
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Cabbage Looper (Trichoplusia ni) Cabbage
Loopers are green caterpillars that should
be hand-picked from leaves as soon as they appear.
At the least, caterpillars will eat holes through leaves
Cutworms are gray caterpillars in or on top of the soil
under young plants. Cutworms eat plants at ground
level.
Aphids appear in groups or colonies and are small
black, brown, gray, green, pinkish or yellow globular-shaped
insects most often found on the underside of
leaves

34. Pests
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Cabbage root maggot (Delia radicum)
Cross-Striped Cabbage Worm
(Evergestis rimosalis)
Flea Beetles are easy to spot on a sunny day
because the sun reflects off their shiny bodies
Onion Thrips are small, elongated brownish
bugs with lighter stripes on each side. These
insects may cause leaves to shrivel, appear
whitish to silver in color and be riddled with
tiny holes giving foliage the appearance of fine
lace.

35. Pests
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Rodents such as gophers, moles,
rabbits, voles and others will eat
young plants or tunnel through
garden soil damaging the root
systems which may provide an
opening for disease
Whiteflies are small flies with white
wings. They are found on the
undersides of leaves. When
disturbed, whiteflies fill the air
around plants

36. Diseases
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Bacterial Wilt causes plants to wither and die.
Blackleg is a fungal or bacterial infection, which
causes the leaves to turn yellow; stems turn
black, rot and die.
Clubroot is caused by a fungus, which lives in
neutral to acid soil compounding this problem
is the fact that this fungus may survive in soil
for more than two decades
Damping Off is a fungal disease, which causes
seeds to decay before they emerge from soil
and seedlings to become soft and rot.
Seedlings fall over and die

37. Diseases
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Downy Mildew is a fungal disease seen
most often when weather is damp.
Leaves are prone to wilt and die
FusariumWilt, more commonly known
as ‘the yellows’ is a fungal disease most
often seen where weather is warm to
hot during the growing season.
Nitrogen Deficiency causes plants to
become weak, lose their color; fading
from a healthy dark green to a pale
yellow or yellow-green

38. Diseases
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Powdery Mildew is a fungus, which causes
a powdery coating over all areas of plants
White Mold is a fungus that causes plants
to yellow and die. Stems and leaves
become covered with white mold and
then rot
Virus Diseases cause stunted, unhealthy
plants with rolled, irregular, crinkled,
yellow, spotted or streaked leaves. Viruses
enter plants through openings caused by
insect pests

39. Viruses
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Plant viruses are responsible for 45% of emerging
plant diseases (fungi 30%,bacteria 16%).
Climate change and the withdrawal of insecticide
active ingredients willexacerbate plant virus disease
problems in the UK.
Natural plant resistance is the most environmentally
friendly, energy efficient and promising approach to
virus control.
Little is known about how climate change will impact
on natural plant virusresistance (single dominant
gene-based resistance often breaks down at
temperatures >300C).

40. The most important viruses
infecting brassicas in the UK
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Turnip mosaic virus (TuMV)
Cauliflower Mozaic Virus (C MV)
Turnip yellows virus (TuYV)
All are transmitted by aphids.

41. Turnip mosaic virus (TuMV)
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Member of Potyviridae
Worldwide distribution
Widest host range of any potyvirus:
all brassicas legumes
lettuce ornamentals
radish rhubarb
Transmitted by 40-50 aphid species:
Myzus persicae
Brevicoryne brassicae

42. THANK YOU
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