Classification of Field Crops

1. Classification of Fields
Crops
BY: Dr. G.A. Shah

2. The importance of classification
 Helps in identification of related crop plants used
for various purposes such as food, feed and fiber.
 Essential for ordinary reference and avoiding
confusion in identification.
For example: there are more than 300 kinds of
clover, which are similar in appearance but differ
from one another in specific ways.
It is difficult to identify and refer to them clearly
without proper naming and classification.

3.  Classification helps to identify a plant
internationally as there are different common
names of same plant species in various region of
the world.
The importance of classification
Trifolium alexandrinum
(Berseem)
Trifolium alpinum Trifolium albopurpureum

4. Botanical classification

5. Botanical classification
 Oldest classification introduced in 370 B.C. by
Theophrastus.
 Carl Von Linne (1707-1778) known as Carolus
Linnaeus modernized it.

6.  Plant kingdom is divided into structural
characteristics into four divisions or phyla.
 Thallophyta
 Bryophyta
 Pteridophyta
 Spermatophyta
Botanical classification
Thallophyta
Bryophyta
PteridophytaSpermatophyta

7. Thallophyta
• Lower forms of plants.
• Do not have roots, stem or leaves.
• These include algae, bacteria and fungi.
• N-fixing bacteria increase soil fertility.
• Smut and rust by fungi.
Botanical classification
Thallophyta
Head smut disease
by fungi
N fixing bacteria

8. Bryophyta
Small green plants higher in scale of thallophyta.
They grow in wet places and widely distributed
worldwide.
None of them are cultivated for human use.
They have no economic importance.
They include mosses, liverworts and hornworts.
Botanical classification
Liverworts HornwortsMosses

9. Pteridophyta
• Green plants with vascular tissues, roots, leaves
and stems.
• They do not have flower and seeds.
• Reproduce themselves by spores.
• They do not have any agronomic value except
ornamental.
• They include Psilophytes, club mosses, horsetail
and ferns.
Botanical classification

10. Spermatophyta
• Most highly developed forms of plant life.
• Produce seed and bear true fruits.
Further divided into two subdivisions:
(i) Gymnosperms
(ii) Angiosperms
(a) Monocotyledons
(b) Dicotyledons
Botanical classification

11. (i) Gymnosperms
• These plants reproduce by a complex structure
known as seed, an embryo plant provided with a
supply of food and covered with a protective
coat.
• These have high economic value.
• Examples are: cone bearing trees such as pine,
fir and cedar.
Botanical classification

12. (ii) Angiosperms
• Highly specialized plants reproducing by seed
within an ovary.
• Include major cultivated crops of economic
importance as food, feed and fiber.
• Examples are wheat, cotton, tobacco etc.
• There are two subcategories of angiosperms
based on the number of cotyledons in the seed.
(a) Monocotyledons
(b) Dicotyledons
Botanical classification

13. (a) Monocotyledons
• These plants have a single cotyledon in the seed.
• Germination is usually hypogeal, i.e. the
cotyledon remaining below ground during
germination.
• These belongs to grass family Gramineae
• Examples are: Maize, wheat, sorghum and
barley.
Botanical classification

14. (b) Dicotyledons
These plants have two cotyledons in the seed.
Germination is usually epigeal, i.e. the cotyledons
come out above the ground during germination.
These plants are usually broad leaved.
Examples are: Gram, Soybean, Cotton and tobacco
Botanical classification

15. Rank Scientific name
Species Aestivum
Genus Triticum
Family Gramineae
Order Graminales
Subclass Monocotyledonae
Class Angiospermae
Division / Phylum Spermatophyta
Botanical classification of wheat
Species: the basic unit in plant classification.
“Group of plants that normally breed among themselves and have
many characteristics in common”.

16. Botanical classification of chickpea
Rank Scientific name
Species Arietinum
Genus Cicer
Family Fabaceae
Order Fabales
Subclass Dicotyledonae
Class Angiospermae
Division / Phylum Spermatophyta

17. Agronomic use classification

18. 1. Cereal crops
• A grass grown for its edible seed.
• Also known as grain crops.
• Examples are wheat, maize, rice, barley, oat,
rye, triticale, sorghum and millet.
Agronomic use classification
rye

19. 2. Forage crops
• Crops which are grazed by the animals or
harvested for green chop, hay and silage.
• Plant material with a dry matter fiber content
over 25%.
• When these are harvested as whole plants and
cured for animal feed, they are termed as
Fodder.
• Mostly belongs to Gramineae or Leguminoseae
• Examples are: Maize, sorghum, grasses, clover
etc.
Agronomic use classification

20. 3. Fiber Crops
• Crops which are grown for their fiber.
• These are used in making textile, ropes and rugs.
• Examples are: Cotton, jute (‫سن‬ ‫,)پٹ‬ flax, sunhemp
(‫,)پٹوا‬ kenaf and sisal.
Agronomic use classification
CottonJute
Flax
Sunhemp
KenafSisal Rug

21. 4. Sugar crops
Grown for their sugar contents.
Examples are: Sugarcane, sugar beet, sweet
sorghum
Agronomic use classification

22. 5. Oilseed crops
• Crops which are grown for the purpose of extracting
oil from their seeds.
• Examples are: Rape and mustard, peanut, sunflower,
safflower, soybean, sesame, casterbean, linseed etc.
Agronomic use classification
Rape and mustard Sunflower Safflower
Soybean Sesame Casterbean

23. 6. Pulses or grain legumes
• Crops belong to family Liguminoseae and are grown
for their edible seed.
• Examples are: Chickpea, pigeon pea, cow pea or
lobia, mung bean, mash bean, faba bean, field bean,
lima bean, lentil etc.
Agronomic use classification
Chickpea Pigeon pea
Mung bean

24. 7. Root and tuber crops
• Vegetable crops grown for under ground parts like
root, bulb, rhizomes, corms and stem tubers.
• Examples are:
• Carrot, radish, turnip, onion, garlic, calocasia (taro),
potato etc.
Agronomic use classification
Taro

25. 7. Root and tuber crops
Bulb: A rounded underground storage organ present in some
plants, notably those of the lily family, consisting of a short stem
surrounded by fleshy scale leaves or leaf bases, lying dormant over
winter, e.g. onion
Rhizome: A continuously growing horizontal underground
stem which puts out lateral shoots and adventitious roots at
intervals, e.g. ginger
Agronomic use classification

26. 7. Root and tuber crops
Corms : A rounded underground storage
organ present in consisting of a swollen stem
base covered with scale leaves. It is not true
bulb, e.g. Taro and Chinese water chesnut
Tuber: A much thickened underground
part of a stem or rhizome, serving as a food
reserve and bearing buds from which new
plants arise, e.g. in the potato
Agronomic use classification

27. 8. Narcotic or drug crops
Those crops which have some narcotic or drug value.
Examples are: Poppy, Tobacco, Tea, Coffee, pepper-
mint.
Agronomic use classification
Poppy
Tobacco Tea
Coffee
Mint

28. 9. Vegetable or garden crops
• Crops which are grown for their edible leaves, shoots,
flower, fruits and seeds.
• Examples are: Asparagus, Broccoli, Cabbage,
Cauliflower, Spinach, Cucumber, Pumpkin, Tomato,
eggplant, okra etc.
Agronomic use classification
Asparagus
Broccoli Eggplant

29. 10. Condiment crops
Crops which are grown and consumed as condiments.
Examples are: Coriander, mint and chilies.
Agronomic use classification

30. Special purpose classification

31. 1. Green manure Crops
• Crops grown and ploughed under in the green
and mature form in order to improve soil fertility.
• Mostly these are legume crops.
• Examples are: Dhaincha, berseem, gaura
Special purpose classification

32. 2. Silage Crops
• Crops are cut and preserved as silage in a
succulent condition by partial fermentation in
silos. Product is known as “haylage”.
• Performed mostly in military dairy farms in
Pakistan.
• Examples are: Oat, maize soybean, sorghum and
grasses.
Special purpose classification
Haylage: silage made from grass
which has been partially dried.

33. 3. Hay crops
• Crops that has been mown and dried for use as
fodder.
• Examples are: Oat, wheat, sorghum and grasses.
Special purpose classification

34. 4. Soilage or green chop crops
• These crops are harvested when still green and
succulent and are fed directly to animals without
curing.
• This is called soiling, zero grazing or green feed.
• Examples are: Berseem, lucerne and maize
Special purpose classification

35. 5. Cover crops
• Crops planted to cover the ground and reduce
soil erosion and nutrient losses by leaching.
• These are usually spreading plants.
• Examples are: moth, mash, grasses, rye etc.
Special purpose classification

36. 6. Catch crops
• Crops grown to fill in when the major crops have
failed or when planting is delayed for some
reason and major crop can not be raised
successfully.
• Examples are: maize and sorghum for fodder
Special purpose classification

37. 7. Companion crops
• Crops grown together as mixture in same field.
• It is also known as polyculture.
• Usually legumes are grown mixed with grasses in
order to increase forage production and improve
forage quality.
• Examples are: Berseem and barley, Berseem and
oat, maize and lobia etc
Special purpose classification

38. 8. Relay crops
• A relay crop is one which is planted as a second
crop after the first crop has reached its
reproductive stage of growth but before it is
ready for harvest.
• Examples are: Sugarcane in sugar beet
Special purpose classification

39. Life cycle based classification

40. 1. Annual crops
• Crops which produce seed and complete their life
cycle within one year.
• Examples are: Wheat, maize barley.
Life cycle based classification

41. 2. Biennial crops
• During the first year, these crops which grow
vegetatively and reserve food in their roots or
other plant parts.
• During the second year, the reserved food is
utilized to produce flower and fruits.
• Examples are: Sugar beet, radish, carrot and
turnip
Life cycle based classification

42. 2. Perennial crops
• Crops which grow for more than two years.
• They may produce seed each year but their life
span is more than two years.
• These have regenerative power to sprout from
their stubble after harvesting.
• Examples are: Sugarcane and alfalfa
Life cycle based classification

43. Classification of crops on basis
of season

44. Classification of crops on basis
of season
1. Kharif / summer crops
Those crops which are planted in summer months
from April to June and harvested in autumn or
winter from October to November.
Examples are:
Maize, Millet, Sorghum, sunflower, groundnut, rice,
cotton, mung bean, mash bean

45. 2. Rabi / winter crops
Those crops which are planted in winter months
from October to November and harvested in
summer from April to May.
Examples are:
Wheat, barley, oat, canola, lentil,
chickpea
Classification of crops on basis
of season

46. Classification of crops on basis
of season
3. Zaid kharif / autumn crops
Those crops which are planted in August-
September and harvested in December-January.
Example are:
Toria

47. Classification of crops on basis
of season
4. Zaid rabi / Spring crops
Those crops which are planted in February-March
and harvested in May-June.
Example are:
Tobacco

48. Classification on basis of
climate

49. Classification on basis of
climate
1. Temperate zone crops
• Crops plants are winter hardy and tolerate very low
temperature. Can tolerate Chilling temperature.
• Grow in latitude between 30° North and 50° south.
• Example of region are: kalam, Swat, Chitral and
Gilgit.
• Examples of crops are: Wheat, Oat and rye
Chilling temperatures extend from
freezing point to, depending on the
model, 7 °C(45 °F) or even 16
°C (60 °F).

50. Classification on basis of
climate
2. Tropical zone crops
• Crops grow where frost does not occur during the
growing season.
• Normal growth is affected by temperature below
10°C.
• Grow in latitude between 20° North and 20° south.
• Plants are killed at freezing temperature.
• Example of region are: Multan, bahawalpur, DI
khan, Peshawar, mardan, Hyderabad etc.
• Examples of crops are: Sugarcane, mango,
pineapple etc.

51. Classification on basis of
climate
3. Sub-tropical zone crops
• Crops can tolerate some sub-freezing temperature,
i.e. below 0°C (below freezing point of water).
• Fruits plants are killed by temperature below -7°C.
• Grow in latitude between 25° North and 40° south.
• Example of region are: Sargoda, sialkot, Mardan,
nawabshah, Mekran etc
• Examples of crops are: citrus, date, fig and
pomegranate etc.

52. Classification on basis of
photoperiod

53. Classification on basis of
photoperiod
Photoperiodism
Response of plant to seasonal change in day length.
• Plants grow vegetatively produce leaves and
branches.
• Then change from vegetative to reproductive stage
by producing flowers and fruits.
• This change is brought about by changes in day
length, i.e. number of hours of light.

54. Classification on basis of
photoperiod
1. Short-day plants / Spring or winter flowering
plants
• These plants change from vegetative to
reproductive stage and produce flowers and fruits
when the day become shorter.
• If they are kept in long day environment, their
vegetative growth will continue and they will not
flower.
• Their day length requirement is less than 12 hours.
• Examples are: soybean, rice, tobacco etc.

55. Classification on basis of
photoperiod
2. long-day plants / Summer flowering plants
• These plants change from vegetative to
reproductive stage and produce flowers and fruits
when the day become longer.
• If they are kept in short day environment, their
vegetative growth will continue and they will not
flower.
• Their day length requirement is more than 12
hours.
• Examples are: Wheat, barley, oat, gram etc.

56. Classification on basis of
photoperiod
3. Day neutral plants
• Plants whose initiation of flowering is not affected
by the length of the day.
• Examples are: tomato, cucumber etc.

57. Classification on basis of photoperiod

58. Classification on basis of
growth habit

59. Classification on basis of
growth habit
1. Determinate plants
• Plants which initiate
their reproductive
growth after
completing vegetative
growth.
• Examples are: Wheat,
barley and rice etc.

60. Classification on basis of
growth habit
2. Indeterminate plants
• Plants whose vegetative
and reproductive stages
continue simultaneously.
• Mature and immature
fruits, flowers and flower
buds are all present on
one plant at the same
time.
• Examples are: Tomato,
cucumber, watermelon
and soybean etc.

61. Classification on basis of mode
of pollination

62. Classification on basis of mode
of pollination
Pollination
Transfer of pollens from an anther to a stigma.

63. Structure of a flower

64. Classification on basis of mode
of pollination
Types of pollination
1. Self pollinated plants
• Those plants in which the pollen from an anther is
transferred to the stigma of same plant: (a) in the
same flower (b) in different flower on same plant.
• Usually only 1-3% cross pollination occurs in these
plants.
• Examples are: Wheat, barley, rice sorghum and
soybean.

65. 1. Self pollinated plants
Classification on basis of mode
of pollination
Within a flower Between flowers

66. Classification on basis of mode
of pollination
2. Cross pollinated plants
• In these plants, the pollen grain from an anther of
one plant is transferred by insects, wind or other
means to the stigma of another plant.
• These plants have open flower and cross pollination
occurs up to 96% of the time.
• Examples are: Maize, Brassica and sunflower.

68. Classification on basis of mode
of propagation

69. Classification on basis of mode
of propagation
1. Sexually propagated plants
• Plants are propagated through seeds.
• Examples are: Wheat, barley, rice, maize, sorghum,
gram etc.

70. Classification on basis of mode
of propagation
1. Asexually propagated plants
• Plants are propagated asexually by using specialized
plant parts or utilizing such cutting, layering and
grafting.
• Examples are: Sugarcane, ginger, potato etc.

71. Classification on basis of mode of
photosynthesis / plant efficiency

72. Classification on basis of mode
of photosynthesis
1. C3 plants
• Plants fix CO2 and form a 3-carbon molecule, 3-
phosphoglyceric acid (3PGA).
• This pathway was discovered by Calvin and his co-
workers (Bassham and Calvin 1957).
• Plants with this pathway of carbon assimilation are
called C3 pathway plants.
• These plants do exhibit photo-respiration.
• Such plants can not utilize CO2, light, temperature
and water efficiently, therefore they are called
INEFFICIENT PLANTS.
• Examples are: Wheat, oat, rye, soybean and cotton etc.

74. Classification on basis of mode
of photosynthesis
2. C4 plants
• In these plants, first product of photosynthesis is a
4-carbon molecule called oxalo acetate.
• Plants fix CO2 via the Hatch and Slack pathway.
• These plants do not exhibit photo-respiration.
• Such plants can utilize CO2, light, temperature and
water efficiently, therefore they are called
EFFICIENT PLANTS.
• Examples are: Sugarcane, maize and sorghum.

76. Classification on basis of mode
of photosynthesis
3. Crassulation acid metabolism (CAM) plants
• CAM plants fix CO2 into 4-carbon acids called malate
as do the C4 plants.
• Fixation of CO2 occurs at night when the stomata
are open.
• CAM plants grow in deserts and have succulent
fleshy leaves and stem with low transpiration and
water requirement.
• Examples are: pine apple, prickly pear

77. Classification on basis of mode
of photosynthesis
3. Crassulation acid metabolism (CAM) plants
• Stomata are closed during day time.
• At night CO2 is collected in leaves.
• CO2 is stored as 4-carbon acid malate at night in
vacuoles.
• At day time malate is transported to chloroplast
where it is converted back to CO2 which is used in
photosynthesis.

79. Classification on basis of
nutrient uptake

80. Classification on basis of
nutrient uptake
1. Restorative crops
• Crops which return nutrient and organic matter to
the soil.
• Examples are: Berseem, alfalfa, soybean etc

81. Classification on basis of
nutrient uptake
2. Exhaustive crops
• Crops which feed heavily on the soil and deplete soil
nutrients.
• Examples are: sorghum, tobacco, sunflower etc.

82. Questions