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**CRSC LECTURE 2** **CLASSIFICATION OF AGRICULTURAL CROPS** Importance of Classifying Agricultural Crops simplify plant collection initiatives, research, breeding and specialized development efforts; facilitate efficient communication, dissemination and retrieval of scientific information ; group...

**CRSC LECTURE 2** **CLASSIFICATION OF AGRICULTURAL CROPS** Importance of Classifying Agricultural Crops simplify plant collection initiatives, research, breeding and specialized development efforts; facilitate efficient communication, dissemination and retrieval of scientific information ; group crops with similar uses, adaptation, growth habits and methods of culture; facilitate intergeneric grafting as practiced with eggplant and tomato of the family Solanaceae, and bottle gourd and other cucurbits with watermelon and melon prevent commonality of some diseases as in potato and tomato useful reference in crop names and identification and as a review guide offer innumerable benefits in finding alternative crops for specific uses i. BOTANICAL CLASSIFICATION OF CROPS The rules on the botanical classification of crop plants are laid down under the International Code of Botanical Nomenclature (ICBN) and the International Code of Nomenclature for Cultivated Plants (ICNCP). The principal ranks of taxa in descending sequence are: 1. kingdom 2. phylum 3. division 4. class 5. order 6. family 7. genus 8. species 9. Variety **The four divisions of the plant kingdom are:** 1. Thallophyta -- algae, bacteria and fungi 2. Bryophyta -- small green plants without true roots or flowers such as the mosses 3. Pteridophyta -- green plants with vascular tissue, true roots, and usually distinct leaves. This group includes the psilophytes, club mosses, horsetails and ferns. 4. Spermatophyta -- all seed-bearing plants that bear true flowers. Majority of the economically important plants are included in this division.  Classification of Corn Kingdom - Plantae Division - Spermatophyta Class - Angiospermae Sub-class - Monocotyledonae Order - Graminales Family - Graminae Genus - Zea Species -- mays Carl von Linne, better known as Carolus Linnaeus, was the originator of this binomial system of plant nomenclature. The publication of his book entitled Genera Plantarum led to the modern taxonomy or classification of plants. The first letter of family names is always capitalized and more often written entirely in capital letters. Most families names end with --aceae attached to a genus name; e.g. Rosaceae, Magnoliaceae, Liliaceae, etc. Eight families, however, do not follow this standard rule. So for the sake of uniformity and consistency, new names have been proposed for these families. The new names appear in parenthesis following the old names. Either the old or the new names can be used In writing scientific names, the first letter of the genus name is capitalized, while the species name is in small letter. Scientific names are italicized or underlined II\. DESCRIPTIVE CLASSIFICATION OF CROPS A. Crop Classifications According to Mode of Reproduction 1. Sexual- plants that develop from a seed after undergoing union of male and female gametes. Examples: rice, corn, mungbean, peanut, squash 2. Asexual- plants which reproduce by any vegetative means without the union of the sexual gametes or by apomixis. Examples: banana, sineguelas, breadfruit, mangosteen. Strawberry B. Crop Classifications According to Mode of Pollination 1\. Naturally self-pollinated crops- the predominant mode of pollination in these plants is self-pollination in which both pollen and embryo sac are produced in the same floral structure. Examples: rice, most legumes, okra, tobacco, tomato 2\. Naturally cross-pollinated crops- pollen transfer in these plants is from the anther of one flower to the stigma of another flower in a separate plant, although selfpollination may reach 5 percent or more. Examples: corn and many grasses, avocado, grape, mango, many plants with unisexual or imperfect flowers. 3\. Both self- and crosspollinated crops- these plants are largely selfpollinated but varying amounts of crosspollination occur. Examples: cotton and sorghum. C. Crop Classifications According to Life Span 1\. Annual- a plant which live within a short period of time, for a few weeks or months, perpetuated by seed, and which die soon after producing seeds; a plant which germinate, grow, flower, produce seed, and die all in one season. Examples: rice, corn, cowpea, mungbean, squash 2\. Biennial- a plant which requires two growing seasons to complete its life cycle, the first for vegetative growth and accumulation of food reserves, and the second for the production of reproductive parts. It grows from a seed, produces flower and seed and then dies in two growing seasons. Examples: bulb onion, cabbage, carrot, celery, raddish. 3\. Perennial- a plant that lives indefinitely, including all trees and shrubs and many herbaceous plants with underground stems (e.g. corm, rhizome, tuber) like banana and clumpforming grasses. Perennial plants continue growing and produce seeds year after year, either from a single plant or, in herbaceous plants, from succeeding re-growth. D. Crop Classifications According To Growth Habit 1\. Herbs- succulent plants with self-supporting stems. Examples: aglaonema, banana, dumbcane, sugarcane, tomato. 2\. Vines- herbaceous climbing or twining plants without self-supporting stems. Examples: charantia (ampalaya), cucumber, luffa (patola), pole sitao, yam. 3\. Lianas- woody climbing or twining plants which depend on other plants for vertical support to climb up to the top of the canopy. These climbers often form bridges between the forest canopy (Wikipedia, 2010). Examples: Climbing bamboo, grape, Jade vine (Strongylodon macrobotrys), rattans, passion fruit. 4\. Shrubs- small trees or tree-like plants, generally less than 5 meters in height but by other authorities it is restricted to small, erect, woody plants which produce several trunks from the base. Examples: Barbados cherry, pink jasmine (kamuning), Siam weed (hagonoy), santan, Lantana. 5\. Trees- plants having erect and continuous growth with a large development of woody tissue, with a single distinct stem or trunk, reaching a height of 5 meters or more. Examples: durian, mango, molave (Vitex parviflora), narra (Pterocarpus indicus), tamarind. E. Crop Classifications According to Leaf Retention 1\. Evergreen- plants that maintain their leaves throughout the year. Abscissed leaves are continually replaced by new flushes. Examples: pines, banana, papaya, palms and most tropical plants. 2\. Deciduous- plants which naturally shed off or lose leaves annually for extended periods. Natural leaf shedding is pronounced in deciduous trees of temperate regions. In the Philippines, defoliation occurs during summer months in Fire Tree (Delonix regia) and red mombin or siniguelas. Many other plants exhibit partial defoliation during drought periods. F. Crop Classifications According to Ecological Adaptation or Habitat 1\. Aquatic, hydrophyte or hydrophytic plant - a plant adapted to growing in water or waterlogged soil. It may grow entirely submerged, partly submerged or floating, or anchored to the ground in bogs, swamps, or beside the edges of ponds, lakes or streams. Examples: azolla, kangkong (Ipomea aquatica), bulrush (Cyperus spp.), lotus (Nelumbo nucifera), water lily (Nymphaea spp.), mangrove species. 2\. Epiphyte or epiphytic plant- a plant that grows aboveground on another plant but is not parasitic, usually deriving only physical support from the host and obtaining nourishment from the air and other sources. Some have roots that take moisture and minerals leached from the canopy of trees and others catch rain and debris in special hollow leaves. The most common epiphytes belong to the pineapple (bromeliad), orchid, and fern families; also called air plant or tree dweller. 3\. Halophyte or halophytic plant- a plant that is able to grow in habitats excessively rich in salts or under saline conditions. Examples: nipa, talisay, bakawan (Rhizophora mucronata) and other mangrove. Coconut, cashew and tamarind have varying levels of tolerance to saline conditions. 4\. Lithophyte or lithophytic plant- a plant adapted to growing on rocks or in rocky terrain with little humus, absorbing nutrients from the atmosphere, rain, and decaying matter which accumulate on the rocks. Vanda, Ascocenda, Ascocentrum, and Trudelia orchids can be grown as lithophytes (McKinley, 2005). Dendrobium has also been grown in pots filled with gravel or stone. 5\. Mesophyte or mesophitic plant-a terrestrial plant which is adapted to moderate conditions for growth, i.e. not too dry and not too wet (e.g. corn and most commerciallygrown crops). 6\. Parasite or parasitic plant- a plant which grows on another plant from which it takes part or all nourishment (e.g. Cassytha, Loranthaceae (mistletoe family), Rafflesia; Neottia and Corallorhiza orchids). 7\. Saprophyte or saprophytic cropgrows on decaying organic matter and has no green tissue. This classification applies to the mushrooms, which are fungi. 8\. Sciophyte or sciophytic plant- a plant that is adapted to low light intensity or shade, e.g. most ferns and mosses, black pepper, cacao, coffee, lanzones, mangosteen, gingers, and many orchids can tolerate or require shade. 9\. Terrestrial or land plant- a plant which grows on land, rooting in the soil. It has aerial parts, collectively called shoot, and an underground part called root which absorbs most of its water and nutrient needs from the soil. Most agricultural crops are terrestrial and are further subclassified into various groups such as halophytes, mesophytes, sciophytes and xerophytes depending on climatic and special adaptations. 10\. Xerophyte, xerophytic or xeric plant- a plant which is adapted to conditions with little or no water. Examples: adelfa, bromyliads, euphorbias, cacti and many succulents. III\. AGRICULTURAL CLASSIFICATION OF PLANTS A crop is any useful plant, or a plant which is grown for any purpose. It is utilized by man directly or indirectly, raw or processed. Direct utilization is exemplified by the use of cereal grains as staple while they are indirectly consumed by man when they are first fed to livestock for meat, or processed into sugar for human consumption. These plants are intentionally grown or managed for various uses such as for food, spices, sugar, drinks, fiber, clothing, beverages, medicines, oils, tannins, rubber, ornamentation, fuels, construction materials, soil improvement, organic farming, landscaping and many more. 2\. Weed. Unlike crop, a weed is an unintended plant or any plant which grows where it is not wanted. It competes with the intended crop for space, soil water, nutrients and light or becomes a nuisance in any manner. Many have allelopathic effect on other plants, both crop and weed, by releasing harmful allelochemicals which are considered plantproduced herbicides Any plant can be a weed, depending on where it grows and how man is affected. Corn is a crop and commercially grown worldwide. But it may become a weed if it grows in a garden plot which is intended for the growing of leafy vegetables or any crop. A tree may also become a weed if it becomes invasive, prevents light penetration, and suppresses the growth of certain crops including pasture grasses. B. Agronomic vs. Horticultural Crops On the basis of tradition, extent of cultivation and intensity of culture, agricultural crops are classified into two main divisions: agronomic and horticultural. 1\. Agronomic crops are also called "field crops". They are mostly annual herbaceous plants that are grown under extensive or large-scale culture. The usable products are usually in high dry matter form. By tradition, cereals, seed legumes, root and tuber crops, sugar crops, latex and rubber crops, pasture and forage crops, and fiber crops are classified under agronomic crops. 2\. Horticultural crops have been referred to as "garden crops". Included in this classification are those grown under any of the fields of horticulture such as: olericulture or vegetable crops production; pomology or fruit crops production; plantation crops and ornamental horticulture (floriculture and landscape horticulture), as well as spices and medicinal plants.. Horticultural crops are annual and perennial plants which are grown under an intensive system of culture. Horticultural products are generally utilized with high moisture content and are therefore highly perishable. From Janick (1972), these crops can be defined as "intensively cultured plants directly used by man for food, for medicinal purposes, or for esthetic gratification". Intensive culture means a large input of capital, labor and technology per unit area of land. **CRSC LECTURE 2.1** **AGRONOMIC AND HORTICULTURAL CROPS** Agricultural Classifications Based on Primary Uses Food Crops -- plants grown primarily for the harvesting of any part which is used by man as food or processed into food product. This classification is a collective term for crops which are variously sub-classified into smaller groups such as cereals, root and tuber crops, legume seed crops, sugar crops, beverage crops, fruit crops and vegetables. Non-food Crops- plants grown for the production of non-food products such as fiber, fodder, alcohol, tobacco, industrial oil, rubber, gums and resins, drugs, etc. or for ornamentation. Included in this classification are fiber crops, pasture and forage crops, rubber crops, latex and gum crops, dye and tannin crops, biofuel crops, essential-oil crops, pesticidal crops and most industrial crops. Staple Crops- plants grown for the harvesting of parts which are used as staple food. A staple food is one that is regularly consumed in such quantities as to form the basis of a traditional diet and from which people obtain a major proportion of their energy and nutrient requirements. In the Philippines, the top staple crop is rice followed by corn. Cassava is also consumed as staple by some ethnic groups. Examples of other staple crops: wheat, banana and plantains, breadfruit, millet, white potato, sweet potato, yam. Cereal or Grain Crops - annual, herbaceous plants belonging to the grass family Gramineae (Poaceae) and some graminoids which are grown for their seeds or grains. The grains are harvested mature and utilized primarily as staple or feed or processed into carbohydrate-rich products. The word "cereal" is derived from Ceres, the ancient Roman goddess of harvest. The grain of cereals is technically a type of single, dry, indehiscent fruit called caryopsis, which has a hard outer pericarp fused to the seed coat. The endosperm predominantly consists of starch. Examples: corn, rice, sorghum, wheat. Legume Seed Crops or Pulsesleguminous plants which produce edible, protein-rich seeds. The seeds are utilized in the mature, dry form as food or feed or processed into various products. The protein quality of legumes is inferior compared to meat because methionine content is generally insufficient. Being leguminous, they are capable of fixing nitrogen from the air through symbiotic relation with Rhizobium bacteria. Examples: soybean, cowpea, mungbean, peanut, peas, pigeon pea (Cajanus cajan). Root and Tuber Crops or Tuberous Crops- plants with modified, swollen root or underground stem. These organs are rich sources of carbohydrate and are commonly used as staple, livestock feed, or as raw materials for industrial purposes, such as starch and alcohol production, or processed into various food products. Crops with modified roots are distinct from those having modified stems. Examples of modified roots are the tuberous and fleshy roots while the tuber and corm are examples of modified stems. A tuberous root is a thickened secondary root as in arrowroot, cassava, sweet potato and yam bean. A fleshy root is usually an enlarged primary root, as in carrot, ginseng (Panax spp.) and sugar beet. The upper portion on which secondary roots develop is hypocotyl or the first internode of the stem. In raddish, the fleshy root consist mainly of the hypocotyl. A tuber is an enlarged tip of an underground stem with leaves reduced to scales or scars subtending the auxillary buds, as in white potato and yam. The "eyes" represent buds in nodes, arranged in spiral pattern from base to the apical end of the tuber. Aerial tubers are called tubercle. Thladiantha spec. Mountain Buffalo the world\'s largest tuber plant A corm, as in gabi,, is a short, solid, underground stem. The corms are usually flattened from top to bottom with numerous roots at the lower part, and a tuft of leaves on the upper. Oil Seed Crops- plants grown for their seeds which are rich source of edible and industrial oil. The important oil seed crops in the world include soybeans, peanut, sunflower, oil palm, sesame and cotton. However, the leading crop in the Philippines is the coconut, followed far behind by oil palm. Permanent oil-bearing crops are perennial plants whose seeds , fruits or mesocarp (olives) and nuts (coconuts) are used mainly for extraction of culinary or industrial oils and fats. Consequently, dessert or table nuts, such as walnuts, are excluded because although they are high in oil content, they are not used mainly for extraction of oil. Sugar and Sweetener Crops - plants grown primarily for the production of sugar or other sweet-tasting products. Sugars, such as sucrose, glucose and fructose, are simple carbohydrates. Sucrose is the common table sugar. Other organic compounds with sweet taste are the mannitol (a colorless crystalline alcohol), stevioside (a complex mixture of diterpene glycosides) and monellin (a protein). These are derived from various parts of certain plants such as from stems, bulb and other underground organs, leaves, flowers, fruits, seeds, sap and resin (Hagelberg, 2003). Examples: sugarcane, sugar beet (a temperate crop), sweet sorghum, Stevia, corn, sweet potato, cassava, rice, many palms. Beverage Crops- plants which are sources of various drinks including fruit juices, tea, coffee, cocoa, toddy, beer and wine. They supply water which is essential to human nutrition. Some of these drinks also provide vitamins and minerals. Others have stimulating or relaxing effects. Examples: cacao, coffee, tea. Rubber Crops- plants grown for the production of latex which is processed into the industrial product called rubber. Rubber is an elastic hydrocarbon polymer constructed of isoprene units. It has widespread uses, from household to industrial products, with the main bulk in the transportation sector. Examples: rubber tree (Hevea brasiliensis), Latex and Gum Cropsplants grown for the collection of latex which is processed into chewing gum, inelastic rubber and other industrial products such as surgical tapes and dental supplies, insulation, splints, pipes, golf balls, waterproofing, adhesives, etc. Examples: chicle tree or chico (Manilkara zapota) Dye and Tannin Crops- plants grown as sources of tannin and coloring substances. Tannin is an aromatic, phenolic substance which is obtained from barks and other plant organs and variously used in tanning, medicines, dyeing, ink manufacture, etc. Examples: anatto or achuete, Indian almond or talisay, indigo (Indigofera tinctoria), bakawan (Rhizophora and Bruguiera). Fiber Crops- plants grown as sources of fiber, a strong, thread-like material used in making textiles, rope, twine and similar materials. The fiber is extracted from the bark, leaves, or other organs including the husk of coconut. Examples: abaca, jute, kenaf, maguey and ramie. Pasture and Forage Crops -- plants grown or managed as vegetable feed for grazing animals. They are classified as either native or improved species, grasses or legumes, and may be fed fresh or dry or in processed form. Examples: carabao grass, paragrass, napier and ipilipil. Soilage Crops- grasses grown, cut and directly fed to animals. Silage Crops- grasses grown, cut, fermented and preserved before being fed to animals. Biofuel Crops- plants grown for the production of fuel that is used as additive or replacement for petroleum products. The main biofuels are bioethanol, an alcohol derived from fermented sugar or starch, and biodiesel from vegetable oils. Examples: sugarcane, cassava, corn, coconut, castor bean, Jatropha. **HORTICULTURAL CROPS** Olericultural or Vegetable Crops -- plants (except mushroom) grown for their succulent and edible parts such as the roots, stems, leaves, young tops, fruits or seeds for use in culinary preparations either fresh or preserved in the fresh state. They are nearly all rich in vitamins A and C with high amounts of dietary fiber. These crops are further classified into different groupings according to similarities in edible parts, growth habits, methods of culture and botanical family. Melons are generally included in this crop classification. FAO (2010) definition: Vegetables are plants cultivated both as field crops and garden crops, both in the open and under glass. Certain gramineous and leguminous plants which, if harvested for the dry grain, are classified among cereals and pulses, belong to this group as far as they are harvested green for the green grains and/or for the green pods (e.g., green maize, green peas, green beans, string beans, etc.). **Vegetable Classifications Based on Edible Part** Leafy Vegetables- these crops are grown mainly for their leaves. They are rich in vitamins and minerals and they also look decorative. Examples: Malabar spinach (alugbate), amaranth (kulitis), lettuce, jute (saluyot), (horse raddish tree) malunggay. Shoot Vegetables- plants grown primarily for their edible shoot, mainly the young, succulent stem. Examples: asparagus, bamboo, celery. Pod and Seed Vegetables- Generally members of Leguminosae or Fabaceae family, these plants are grown for their young pods and seeds. Examples: snap bean, pole sitao, and winged bean Root and Bulb Vegetables- plants grown for their swollen underground roots and stems. Examples: carrot, potato, onion, raddish, sugar beets Flower Vegetables- plants with edible flowers. Examples: horse raddish tree (malunggay), katuray (Sesbania grandiflora), squash, banana blossom Fruit Vegetablesgrown for their fleshy, succulent fruits. Examples: ampalaya, eggplant, tomato, peppers, melons. Vegetable Classifications by Family Cole Crops or Crucifersthese vegetable crops belong to the Cruciferae or Brassicaceae (Mustard) family, with edible leaves or heads. Examples: cabbage, cauliflower, mustard, pechay, Chinese cabbage, raddish. Cucurbits- belong to the Cucurbitaceae (Gourd and Squash) family. They are grown mainly for their fruits but some have edible young shoots and flowers; also called Vine Crops. Examples: bottle gourd, charantia, cucumber, luffa, melons, squash. Legume Vegetablesmembers of the Leguminosae or Fabaceae (Bean) family. The seeds are rich in protein. Examples: bush sitao, katuray, kidney bean, lima bean, pea, pole sitao. Lilies- members of the Liliaceae (Lily) family. Examples: asparagus, garlic, onion. Solanaceous Cropsbelong to the Solanaceae (Nightshade or Eggplant) family and, with the exception of white potato, are also called Fruit Vegetables. Examples: eggplant, tomato, peppers, white potato. Mushrooms- these are edible fungi belonging to the division Basidiomycota (club fungi). The edible part commonly consist of an upright stalk and an umbrella- shaped cap. Examples: straw mushroom, Shiitake mushroom, puffball, termite mushroom, "kabuting-higante Pomological or Fruit Crops and Nuts-- plants grown primarily for their edible fruits or closely related structures which, as a rule, are consumed raw. FAO (2010) definition: Fruit crops are those yielding fruits and berries which generally are characterized by their sweet taste and their high content of organic acid and pectin. Fruits borne on trees are called tree fruits, among which are the duhat, durian, jackfruit, mango, mangosteen and santol. Fruits borne on lowgrowing plants such as shrubs, vines, lianas and some herbs are called small fruits (e.g. grape, passion fruit, pineapple, strawberry). Fruits are often important sources of vitamin C, and many contain carotene. They are high in cellulose but usually has little fat or protein and little to no starch. A parcel of land that is planted to fruit crops is called an orchard. Nuts are grown for their fruits which are high in fat. The nut is a simple, dry, indehiscent fruit with a hard outer covering. Examples: cashew, pili. Spice Crops- plants grown for the production of aromatic materials or substances which are used as food flavoring or for other purposes because of their fragrance or preservative qualities. Spices are in solid or liquid forms. Examples: black pepper, garlic, ginger, hot pepper, onion, turmeric. FAO (2010) definition: Spices are plants which, in one or the other of their components (rhizome, bark, fruits, berries, seeds, etc.), contain strongly flavoured and aromatic substances, and for that reason are used mainly as condiments. Most of them are perennial. Essential-oil Cropsplants grown for the extraction of essential oils which are volatile, aromatic substances for perfumery and other uses. Examples: citronella, eucalyptus, ilang-ilang, peppermint, sampagita. Ornamental Crops -- plants which are grown primarily for decoration or landscaping or to be appreciated because of their attractive flowers or foliage. They are further classified as cutflowers, cut foliage, turfgrasses, groundcovers, hedges, accents, specimen plants, avenue trees, screens, topiaries, fillers and others. Floricultural crops are valued for their attractive flowers, foliage ornamentals for their leaves. Lawn or Turf Grassesgrasses grown for aesthetic purpose in the landscape or for any outdoor recreational use. They are usually maintained at a low height. Examples: Bermuda grass, carabao grass, creeping bent grass, perennial rye grass. Cutflowers- plants grown for their attractive flowers with long shelf life. Examples: anthurium, chrysanthemum, gladiolus, orchids, rose. Cutfoliage- plants grown for their attractive foliage which are cut for floral decoration. Examples: ferns, fishtail palm, kamuning, Song of India, Song of Jamaica. Edge Crops- short statured plants grown to serve as barrier between the lawn and garden, to highlight gardens, or to create stand-alone gardens; also called border plants. Examples: mondo grass, dwarf cucharita, dwarf sansevieria. Groundcovers- low-lying, aesthetically appealing plants grown in the landscape primarily to suppress weed growth and to control, retard or prevent soil erosion by covering and binding loose, bare soil It is oftenly used en masse to produce a carpeting effect. Examples: cucharita (Alternanthera versicolor) , Cuphea, travelling jew, creeping peanut, Vietnam rose. Hedges- plants grown at the edges of pathways or boundaries and continuously pruned to knee-high height or upper but below eye level. Examples: Duranta, hedge bamboo, Chinese holly, dwarf santan, papua. Accents- plants with showy features distinct from the rest of the other plants. It immediately attracts attention and becomes a focal item in the landscape garden and at the same time provides the contrast which gives attention to other plants. Specimens- plants having showy features, or with unique characteristics which make them pieces of conversation or botanical curiosity, or otherwise desired as collector's item. They are ideally planted in isolation rather than massed with other plants, and easily become focal point in the landscape. Examples of potential specimens: queen of flowering trees (Amherstia nobilis), palms, Mussaenda 'Doña Eva' Screens- plants grown to serve as barrier against sun rays, to conceal certain parts of the landscape, or to obstruct view. Examples: Indian tree, shrubs, trellised vines. Shade crops- generally trees, shrubs, trellised vines and lianas which are grown mainly to provide shade singly or with supporting trellis. Avenue Trees- trees and shrubs grown, more or less equidistant, beside roads and streets. Palms are also used. Examples: acacia (raintree), katuray, narra, Norfolk Island pine, date palm. Biocidal Crops- plants containing organic compounds with pesticidal or anti-microbial properties. The effective parts are either directly applied or seeped in water for foliar spray. Many have been commercially exploited by extracting the active ingredients. Examples: chrysanthemum (Chrysanthemum cineriaefolium), kayos (Dioscorea hispida), lagtang, makabuhay (Tinospora crispa), tobacco, tubli (Derris elliptica), neem. Plantation Crops -- plants grown in large tracts of land under intensive culture, usually in a tropical or subtropical country, where products are sold in distant markets rather than for local consumption. This classification is based on the extensiveness of production, system of culture required, and market location. It requires plenty of labor and large investment of capital. Many of those who are engaged in the growing of plantation crops are corporate organizations and multinational companies like Dole Philippines and Del Monte. Any crop can be suited for growing in a plantation. Thus there are plantations which are devoted to fiber crops (abaca), trees (e.g. falcata, mahogany), bamboo (e.g. giant bamboo, thorny bamboo), beverage crops (coffee, cacao, tea), fruit crops (e.g. banana, pineapple), nuts (e.g. cashew), vegetables (e.g. asparagus), spices (e.g. turmeric), and aromatic crops (ilang-ilang, vanilla) **CRSC LECTURE 2.2** **SPECIAL-PURPOSE CLASSFICICATION OF CROPS** Special-Purpose Classifications of Crops There are other groupings of agricultural crops or crop-epithets which are commonly used but cannot be appropriately placed under either agronomic or horticultural classification. These classifications do not consider the direct benefit of the crop to the ultimate consumer, nor to the extent of cultivation and the intensity of care required. These classifications are used to refer to plants having special advantages to the farmer himself in relation to his farming practices. Main Crop- any crop which is intended by the grower to become his main source of revenue. Nursery crop- a plant that is temporarily grown in the nursery and later planted in the field or garden or used for ornamental display when it reaches the proper age and size (e.g. most fruit crops and ornamental crops Intercrop- any crop which is planted simultaneously with or before the flowering season of the main crop in intercropping. Filler Crop- any crop which is planted to fill a gap. In quincunx system of planting arrangement, the space at the center of four hills of a main crop is commonly intended for a filler crop which is of a different variety or species. Relay Crop- the crop which is planted after the flowering period or harvest of the main crop in relay cropping. Ratoon crop- the crop consisting of the regrowth from shoots retained on the plants after harvest or from cut stalks of the previous crop (e.g. pineapple, sorghum, sugarcane) Cash crop- any short-maturing crop which is grown to generate income while the main crop is still in its vegetative stage of growth; any crop is grown to generate cash rather than for subsistence. Catch crop- any short maturing plant that is grown simultaneously with, or between successive plantings of a main crop to utilize residual fertilizer and soil moisture. It is often used as a green manure or to provide supplemental livestock feed; also called emergency crop. Nurse crop- any crop which is grown to provide shade and increase humidity for the benefit of the main crop during its seedling and early stages of growth. Companion crop- any crop which is planted close to the main crop to complement the latter's growth and production, or to maximize utilization of space because they do not compete. Examples: a\. Black pepper is planted with live madre de cacao (Gliricidia sepium) to serve as trellis. b\. Lettuce acts as a living mulch to keep the soil moist while sunflowers to the south or west provide shade for the vegetable. c\. Planting squash and onions will maximize production per unit area of land. These crops occupy different root zones, squash being deep rooted while onion is shallow rooted. Cover crop- a crop grown mainly to control soil erosion, regulate soil temperature, control weeds and reduce evaporative losses. Leguminous vines such as improved pasture and forage crops are excellent cover crops. As legumes they can enrich the soil fertility by fixing atmospheric nitrogen. Green manure crop- a leguminous crop grown to be plowed under the soil to increase organic matter and serve as organic fertilizer. Mungbean (mungo) is ideal for this purpose. Seeds of mungbean are commonly broadcasted in a field of rice immediately after harvest and allowed to grow using residual water, thus also becoming a catch crop. In time for tillage in preparation for the next rice crop, the mungbean plants are plowed under and allowed to decompose. Agroforest Crop -- any crop which is suited under a cropping system consisting of mixed agricultural and forest crops. Contour Hedgerow Crop- nitrogen-fixing trees and shrubs which are grown along contour lines in sloping lands under the Sloping Agricultural Land Technology (SALT). These crops are grown mainly to produce green manure and mulch, to serve as firebreak, to stabilize the soil and to control soil erosion