AGRI 31 1ST LEARNING GUIDE

• Crops are diverse, and the identification of these crops remains essential in agriculture,

  particularly in propagation, collection, weed and toxic plant discrimination. In the field, a crop can be identified through its gross morphology. The identification is made if the morphological characteristics of the unknown plant fall within the range of the diagnosis of a

  known one (Simpson, 2006). Hence, crops are described and subsequently judged based on similarity. The assessed features of the crop are then associated with its common name or scientific name.
• Scientific names are names assigned by the rules of the International Code of Nomenclature

  for algae, fungi, and plants (ICN) and the International Code of Nomenclature for Cultivated

  Plant (ICNCP).
• Three system of classification of crops:

  
  

  1. Artificial System
  2. Natural System
  3. Phylogenetic System
• The artificial system is based on convenience in which a structure or feature serves as a basis of grouping.

  
  

  Another system is the natural system which utilizes the most prominent and the most peculiar morphological structure of the plant to group together those crops which are most similar in a number of

  structures.

  
  

  In the phylogenetic system, plants are classified according to their evolutionary

  status.
• General Classification of Crops according to the mode of reproduction

  1. Sexual
  2. Asexual
• a.According to the mode of resproduction

  i. Sexual – plants that develop after undergoing meiosis and

  fertilization in the flower to produce a viable embryo in the seed.

  ii. Asexual – plants that are produced by any vegetative means not involving meiosis and the union of gametes. e.g., grafting, cuttings, tissue culture
• b. classification of crops according to the life cycle

  i. Annuals – complete their cycle in one growing season. These plants germinate from seed, induce vegetative growth, flowers, fruits, and seeds, and die within one growing season. e.g., squash, rice

  ii. Biennials – plants ordinarily require two years or at least part of two growing seasons with a dormant period between growth stages to complete their life cycle. e.g., celery, carrot, cabbage

  iii. Perennials – plants that do not die after flowering but live from year to year. e.g., fruit trees, coffee, coconut, lagundi
• c. Classification of crops according to growth habit

  i. Herbs – succulent plants with self-supporting stems

  ii. Vines – succulent plants without self-supporting stems

  iii. Shrubs – may have several main branches with no trunk and rarely grows higher than five meters

  iv. Trees – with single central stem to which branches are

  attached, usually taller than a shrub

  v. Liana - long-stemmed, woody vines that are rooted in the soil and use trees and other structures for vertical support
• Classification of crops based on use or purpose for which the crop is grown:
• Cereals/grain crops - grasses grown for their grains:

  • Examples include rice, corn, wheat, sorghum
• Legumes - grown for pods and seeds:

  • Examples include soybean, peanut, mungbean, string beans, cowpea, ricebean, winged bean, pigeon pea
• Root crops - grown for enlarged roots/tuberous roots:

  • Examples include cassava, sweet potato, purple yam, arrowroot
• Fiber crops - grown for fibers used in textile, cordage, twines, sacks, bags, etc.:

  • Examples include cotton, ramie, kenaf, jute, abaca, buri, kapok (Engl. silk-cotton tree), maguey
• Oil crops - grown for their oil content:

  • Examples include soybean, peanut, sunflower, castor, coconut, African oil palm, lumbang (Engl. candlenut), safflower
• Sugar crops - grown for their sugar content:

  • Examples include sugarcane, sugar beet
• Pasture/Forage crops - used as a roughage source for animals:

  • Examples include various grasses like para grass, napier grass, guinea grass
• Beverage crops - used for brewing non-alcoholic drinks:

  • Examples include coffee, cacao, tea
• Spices, condiments, essences - used to provide special flavor, scent, and color:

  • Examples include black pepper, vanilla, citronella, ylang-ylang, annatto
• Latex and resins - used for extracting sap from the trunk/stem:

  • Examples include rubber, chico, pili, rimas, papaya
• Medicinal and poison crops - with curative, laxative, and pesticidal properties:

  • Examples include lagundi/five-leaved chaste tree, tsaang gubat/Fukien tea tree, sambong/Nagi camphor, yerba buena/wild mint, golden shower, tobacco
• n. Vegetables – usually eaten with staple crops, further classified according to similarities in the method of culture

  i. Root – e.g., carrot, radish

  ii. Leafy – e.g., pechay, mustard, lettuce, swamp cabbage or tropical

  spinach, spinach

  iii. Stem – e.g., potato, celery, asparagus

  iv. Flower – e.g., squash, katuray/Sesbania

  v. Fruit – e.g., okra, tomato, eggplant
• o. Fruits – edible botanical fruits usually used for dessert which may be eaten raw, cooked or in processed form

  i. Small fruit – e.g., pineapple, grapes, strawberry

  ii. Nut fruit – e.g., cashew

  iii. Tree fruit – e.g., durian, mango, santol
• Ornamentals are plants cultivated mainly for their aesthetic value
• Ornamentals are further classified according to their special uses
• Cut flowers or florist crops are grown for their flowers, examples include gladiolus, roses, daisies, chrysanthemum, anthuriums, orchids
• Cut-foliage or florist greens are foliage that provides the background in a floral arrangement, examples include ferns, asparagus, fortune plant, palmera (Engl. butterfly palm)
• Flowering pot plants are plants grown in containers for their beautiful flowers, usually used for display purposes, examples include kalanchoe, African violets, poinsettia
• Landscape plants are used for landscaping purposes such as ground cover, barrier, specimen, edging, accents, filler, examples include blue palm, white grass, Bangkok kalachuchi, Song of India
• Foliage plants are grown for their attractive foliage, may be grown indoor or outdoor for decoration, examples include begonia, philodendron, aglaonema
• Turf is used in lawns or greens, examples include bermudagrass, carabao grass, bluegrass
• Special groups of crops in agriculture:
• Green manure:

  • A crop that is plowed under while still green and growing to improve the soil
  • Examples include sesbania and kakawate
• Cover crop:

  • Any crop grown to provide soil cover, prevent soil erosion by wind or water, improve soil, and control weeds
  • Example: Centrosema
• Companion crop:

  • A crop sown with another crop and harvested separately
  • Combination benefits either or both of the crops
  • Example: small-grain cereal crops are often sown with forage crops (grasses or legumes) and harvested in the early summer, allowing the forage crop to continue to grow
  • Living ipil-ipil used as live trellis for black pepper
• Trap crop:

  • Planted to protect the main crop from pests by attracting the pest to the crop itself and later destroying it
  • Example: main crop is rice and sweet potato is planted to trap some rats; main crop is cotton and okra is planted every after five rows of cotton to attract the cotton stainer away from the cotton
• Catch crop:

  • A short-seasoned crop grown immediately after the failure of the main crop to utilize residual resources
  • Example: rice is the main crop but may have been destroyed by typhoon therefore pechay or mustard is planted immediately
• Soilage:

  • Grasses grown, cut, and directly fed to animals
• Silage:

  • Grasses grown, cut, fermented, and preserved before being fed to animals