This document discusses different ways of classifying crops in agronomy. It describes how crops can be classified based on their life cycle as annual, biennial or perennial crops. It also discusses classifications based on economic use, seasons, climate, root system, photosynthesis pathways, photoperiod requirements, and more. Key classifications mentioned include cereals, pulses, oilseeds, sugar crops, fibers crops, fodder crops, spices and condiments. Common examples are provided for each classification type.

1. Unit I Introduction to Agriculture
Dr. S. Marimuthu., Ph.D.
Asst. Professor (AGR)
Agronomy: relationship with other disciplines
Classification of crops

2. Agronomy
• Pivotal position - “Mother branch or primary branch”
• Integrated and applied aspect of different disciplines of pure
sciences
• (i) Crop Science, (ii) Soil Science, and (iii) Environmental Science

3. Relationship with other discipline
• Crop science - Plant breeding, crop physiology and
biochemistry etc.,
• Soil science - Soil fertilizers, manures etc.,
• Environmental science - Meteorology and crop ecology.

4. Crops
• Organism grown or harvested for yield
• Agronomy - “Plant cultivated for economic purpose”
Classification of crops
• Similar crop plants - better understanding of them

5. Classification types used in crops
• Based on ontogeny (life cycle)
• Economic use (Agronomic)
• Botany (Scientific
Classification)
• Based on seasons
• Based on climate

6. Based on Ontogeny (life cycle)
Annual crops:
• Complete life cycle within a season for year
• Eg. Wheat, Rice, Maize, Mustard
Biennial crops:
• Life span of two consecutive seasons or years
• First years/ season - purely vegetative growth
• Second year / season - Reproductive development -
Eg. Sugar beet, Beetroot, Cabbage, Radish, Carrot, etc.

7. Based on Ontogeny (life cycle)
Perennial crops:
• Three or more years
• Seed bearing or non-seed bearing
• Eg. Napier fodder grass, coconut etc

8. Based on economic use (Agronomic)
Cereals - Poaceae
• Stable food - World (only 5% from
root crops)
• Cultivated as grasses - edible starchy
(60-70%)
• Vitamin E, 20% to 30% minerals of
selenium, Ca, Zinc & Cu
• Straw – feed to animals
• Eg. …………………

9. Rice/ Paddy
Oryza sativa
Wheat
Triticum vulgare/eastivum

10. Maize
Zea mays
Barley
Hordeum vulgare

11. Rye
Secale cereale
Oats
Avena sativa

12. Triticale – Man made cereal – Oat x Wheat
Tritico secale

14. Nutri-Cereals or Millets
• Small grained cereals - staple food -
developing countries
• Annual grasses - grown in lesser area
• Grains - Panicle
• Sorghum, cumbu - Ear heads
• Used after ‘Dehusking’
• Flour - delicious food items
• Fodder crops – animals
• Eg………….

15. Sorghum / Jowar /
Cholam
Sorghum bicolor
Pearl Millet / Bajra /
cumbu
Pennisetum glaucum

16. Finger millet or Ragi
Eleusine coracona
Fox tail millet / Thenai
Setaria italica

17. Little millet / Samai
Panicum miliare
Common millet /
Panivaraugu
Panicum miliaceum
Poor fertility

18. Barnyard millet /
Kudiraivali
Echinchloa colona var frumentaceae
Kodomillet / Varagu
Paspalum scrobiculatum
Fast growing Long duration

19. Pulses
• Seeds of leguminous plants - food, more
protein
• N fixation – Rhizobium – Root Nodule
• Pod - economic portion
• Mostly used in cropping system
• Green manure, High value cattle feed (Crops &
seed coat)
• As vegetables, e.g., cowpea, lablab
• Wastes or stalk - ‘Haulm’ or ‘Stover’

20. Redgram - Cajanus cajan

21. Blackgram - Vigna mungo

22. Greengram - Vigna radiata

23. Chick pea - Cicer arietinum

24. Cowpea - Vigna unguiculata

25. Horsegram - Macrotyloma uniflorum

26. Soybean - Glycine max

27. Peas - Pisum sativum

28. Lab lab – Lablab purpuris

29. Oil seeds
• Rich in fatty acid - vegetable oil
• Edible/industrial/medicinal purposes
• Oil content - 20% to 50%
• Protein, Vit A, B and B2
• Oil cake - manure and feed for cattle
• Haulms are feed to livestock

30. Groundnut or peanut - Arachis hypogeae

31. Sesamum or gingelly – Sesamum indicum

32. Sunflower - Helianthus annuus

33. Castor - Ricinus communis

34. Linseed or flax- Linum usitatissimum

35. Niger - Guizotia abyssinia

36. Safflower - Carthamus tinctorius

37. Rapeseed & Mustard- Brassica juncea

38. Sugar Crops
• Juice extracted from stem - Jaggery or sugar
• By products: Molasses (Alcohol & Yeast
formation), Bagasse (Paper making & Fuel),
Pressmud (Soil amendment)
• Trash (green leaf + dry foliage) - cattle feed
• Sugarcane - Saccharum officinarum
• Sugar beet - Beta vulgaris

39. Fibre crops
• Plants grown as fibre
• Seed fibre - Cotton (Gossypium spp.)
• Stem / Bast fibre - Jute (Carthamus
tintorius), Mesta (Hibiscus cannabinus)
• Leaf fibre - Agave (Agave americana)
Pineapple (Ananas comosus)

40. Fodder / Forage crops
• Vegetative matter, fresh or preserved,
utilized as feed for animals
• Hay, silage, pasturage and fodder
• Eg. Grasses = Bajra napier grass,
Guinea grass, Fodder sorghum, Fodder
maize, etc
• Legumes = Lucerne, Desmanthus,
Fodder cowpea, etc.

41. Spices and Condiments
• Crop plants or their products used
as flavour, taste and add colour to
the fresh or preserved food
• Eg. Ginger, Garlic, Fenugreek,
Cumin, Turmeric Chillies, Onion,
Coriander etc.

42. Medicinal plants
• Crops used for preparation of medicines
Eg. Mint, Thulsi etc

43. Beverages
• Crop products used as mild, agreeable & simulating drinking
• Eg. Tea, Coffee, Cocoa (Plantation crops)

44. Green manure
crops are grown
and buried in the
same field
Insitu - Green manures

45. Exsitu - Green leaf manures
Turning into the soil
green leaves and tender
twigs collected from
shrubs and trees grown
on bunds, waste lands
and near by forest areas

46. GM Vs GLM

47. Scientific or Botanical classification
• Botanical or scientific names of plants which consist of genus and species
- universally accepted
• Carolus Linnaeus (Swedish botanist ) “Binomial system of classification”

48. Based on Seasons
• Kharif: June - July to Sep - October
(Warm wet & shorter day length for
flowering)
• Eg. Rice, Maize, Castor, Groundnut
• Rabi Crops
• Oct. – Nov. to Jan - Feb (Cold dry &
longer day)
• Eg. Wheat, Mustard, Barley, Oats,
Potato, Bengal gram, Berseem,
Cabbage and Cauliflower
• Summer (Zaid crops)
• Feb. - March to May - (Warm dry &
longer day)
• Eg. Black gram, Greengram,
Seasame, Cowpea etc.
• Classification is not a universal
one. Indicate the period for
particular crops grown
• Eg. Kharif rice, Kharif maize, Rabi
maize, Summer pulse etc.

49. Based on Seasons

50. Based on climatic condition
• Tropical crop : Coconut, sugarcane
• Sub-tropical crop : Rice, cotton
• Temperate crop : Wheat, barley
• Polar crop : All pines, pasture grasses

51. Classification based on cultural method/water
• Rain fed: crops grow only on rain water
• E.g. Jowar, Bajara, Mung etc.
• Irrigated crops: Crops grows with help of irrigation
water - Chili, sugarcane, Banana, Papaya etc.

52. Classification based on root system
• Tap root system: Main root goes
deep into soil
• E.g. Tur, Grape, Cotton etc.
• Adventitious or Fiber rooted:
Shallow & spreading into the soil
• E.g. Cereal crops, wheat, rice etc.

53. Classification based on economic importance
• Cash crop: Grown for earning money
• E.g. Sugarcane, cotton etc.
• Food crops: Grown for raising food grain
& fodder for cattle
• E.g. Jowar, Wheat, Rice etc.

54. Classification based on photosynthesis
• C3 Plants: Photo respiration is high and low WUE
• E.g. Rice, soybeans, wheat, barley, cotton, potato.
• C4 plants: High photosynthetic, WUE, Drought resistant
• E.g. Sorghum, Maize, Napier grass, Sesame etc.
• CAM plants: Stomata opening at night, High WUE and
drought resistant
• E.g. Pineapple, Sisal and Agave

55. Classification based on length of photoperiod
• Photoperiodism: Required relative length of
the day & night, for floral initiation
• Short-day: Flower initiation required <10 hrs
• E.g. Rice, Jowar, green gram, black gram etc.
• Long day’s plants: Flower initiation - >10 hrs
E.g. Wheat, Barley
• Day neutral plants: Photoperiod does not
influence for phase change of plants. E.g.
Cotton, sunflower.

56. Thanks a lot