Fundamentals of horticulture

Fundamentals of horticulture

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  FUNDAMENTALS OF HORTICULTURE UNIT-1 B.PAVAN KUMAR NAIK DEFINITION OF HORTICULTURE Horticulture can be very broadly defined as the science with deals with the production utilization and improvement of (fruits, vegetables, ornamental plant spices and condiments, medicinal and aromatics, plantation crops) as well as gardening, protective cultivation and value addition. Horticulture as a science Over and above agriculture it involves the application of physics, chemistry and other fundamentals sciences and plant sciences viz. biochemistry, plant physiology, botany, genetics and plant breeding etc. Horticulture as an art Artistic application of technical knowledge gained e.g. raising flowering plants in small pot, budding roses with varied colours, pruning trees for shapes, designing gardens, growing flowers of matching colours and according to the seasons etc. OBJECTIVES To find out way by which horticulture crops can be made to yield optimum benefits to mankind. These objectives can be achieved through - The knowledge of geographical distribution of horticultural plants - The source and uses of such plants their structure and manner of growth - The influence of climate and soil on their development - The methods of their propagation - The manner, time and degree of pruning them - Their diseases, pests and their control and - The manner of harvesting, storing, transporting and using the finished products DIVISION OF HORTICULTURE 1. Pomology: The term Pomology is derived from the Latin word ‘pomum’ meaning ‘fruits’ and the Greek term ‘logy’ meaning Science. Thus, pomology is the science of production of fruit crops. OR The science of growing fruit crops. (a) Tree fruits: Fruits are produced on tree e.g. Mango, Chiku, Citrus etc.
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  (b) Small fruits:Fruits are produced on shrubs or vines e.g. Phalsa, Raspberry, Mulberry, Grapes, Gooseberry, Strawberry 1. Olericulture: The term Olericulture is originated from Latin word ‘oleris’ meaning pot herb and the English word culture meaning raising of plants. Thus, olericulture is the science of vegetable crops. OR The cultivation of vegetable crops. e.g. brinjal, tomato, potato, radish, carrot, chilli, bottle gourd. 2. Floriculture: It is a science of cultivation of flowers and ornamental plants for commercial purposes or merely for getting pleasure and as a hobby. 3. Landscape gardening: It is a science of designing and laying out home gardens, public gardens, parks, road side plantation, avenues etc. 4. Preservation of fruit and vegetables: It is a science of canning of fruits and vegetables. e.g. fruit juice, jam, marmalade, candy, dehydration etc. 5. Silviculture: Cultivation and management of forest tree e.g. teak wood, neem, ficus, eucalyptus etc. 6. Plantation crops: Cultivation of tea, coffee, coconut, arecanut, rubber, oil palm etc. 7. Spices and condiments: Cultivation of crops which products are used as adjunct in food for flavor, aroma and taste. e.g cardamom, clove, nutmeg, coriander, cumin etc. 8. Aromatic and medicinal plants: cultivation of aromatic and medicinal plants like gugal, aonla, beheda, harde, lucorice, lemon grass etc. 9. Sericulture: Deals with rearing of silkworm and production of silk. 10. Apiculture: Bee keeping rearing for honey production. 11. Mushroom production: Production of different edible species of mushroom like Agaricus bisporus (button), pleurotus sp. (oyster), Calocybe indica (Milky), Volvariella volvacea (paddy straw). IMPORTANCE OF HORTICULTURE  Fruits and vegetables play an important role in the balance diet of human being by providing vital protective nutrients.  They not only adorn the table but also enrich health from the most nutritive menu and tone up the energy and vigour of man.  Fruits and vegetables have a key role in neutralizing the acid produced during digestion of protein rich and fatty foods.  They provide valuable roughages which promote digestion and helps in preventing constipation.  From unit are of land more income is obtained by growing fruits and vegetables crops.  From energy point of view the fruit crops give very high amount of calories per acre e.g. wheat 1034880 calories/acre and banana 15252800 calories/acre.  Horticulture is mother of several industries like canning, essential oil, dehydration, refrigeration, wine, cashew nut, transport etc. which provide work for many people. Farmers and labours can keep themselves engaged busy throughout year.  Growing of horticultural crops is an art as well as science which help in mental development of farmers.  The fruits and vegetables are chief source of vitamins and minerals which help in proper health and resistant to disease.
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   The flowers,ornamental plants and gardens play a very important role in refreshing the minds of people and reducing air pollution.  The growing of horticultural crops also contributes to the aesthetic side of rural and home life of community.  Generate employment opportunities.  Wide source of medicine.  Effective utilization of wasteland through hardy fruits and medicinal plants. SCOPE OF HORTICULTURE  India has great variety of climate and edaphic conditions which can be exploited by growing horticultural crops.  Climates are varying from tropical, subtropical and temperate regions. From this humid, semi-arid, arid and varying temperature trees are also grown.  Likewise soils like loamy, alluvial, laterite, medium black, rocky shallow heavy black sandy etc are also available. From this, large crop areas can be grown with very high level of adaptability.  To meet the requirements in terms of vitamins and minerals, minimum of 85 g of fruits and 200 g of vegetables per head per day with population of above 1000 million people, fruit and vegetables are to be grown on large scale.  For providing raw material to small scale industries like silkworm, lack, honey, match, paper, canning, and dehydration etc. horticulture has wide scope.  In India larger area of lands are waste land, problematic soil, desert land which can be utilized for hardy fruits and medicinal plants.  The fast development of communication and transport system create wide scope for horticulture development particularly in transporting the perishable commodities and products. Thus horticulture has great scope for the following reasons:  To exploit great variability of agro-climatic conditions.  To meet the need for fruits, vegetables, flowers, spices beverages in relation to population growth and nutritional requirement.  To meet the requirement of processing industries.  For increasing export and import of horticultural products.  To improve economical condition of the farmers.  To generate employment opportunity for labour and human being.  To protect environment. HORTICULTURAL CLASSIFICATION 1. Botanical classification: (Classification of Horticultural crops) A) Botanical classification of vegetables: a) Monocot: i) Areaceae – Colocassia. ii) Alliaceae – Onion, Garlic. iii) Diascoreaceae – Yam b) Dicot: i) Chenopodiaceae – Spinach. ii) Cruciferae – Cole crops, Turnip, Radish. iii) Leguminosae – Pea, Beans, Fenugreek. iv) Euphorbiaceae – Tapioca.
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  v) Malvaceae –Okra. vi) Umbelliferae – Carrot. vii) Convolvulaceae – Sweet potato. viii) Solanaceae – Tomato, Brinjal, Chilli, Potato. ix) Cucurbitaceae – Gourds, Melons, Pumkin. x) Compositae – Lettuce B) Botanical classification of fruits: a) Monocot: i) Musaceae – Banana. ii) Bromeliaceae – Pineapple. b) Dicot: i) Rhamnaceae – Ber. ii) Sapotaceae – Chiku. iii) Rutaceae – Nagpur Santra, Sweet Orange, Acid lime. iv) Annonaceae – Custard apple, Bullock’s heart. v) Moraceae – Fig, Jackfruit. vi) Vitaceae – Grape. vii) Myrtaceae – Guava. viii) Apocynaceae – Karonda. ix) Anacardiaceae – Mango, Cashew nut. x) Caricaceae – Papaya. xi) Punicaceae – Pomegranate. C) Botanical classification of plantations and spices: a) Monocot: i) Arecaceae (Palmae) – Coconut. ii) Arecaceae (Palmae) – Arecanut. iii) Alliaceae – Onion, Garlic. iv) Zingiberaceae – Turmeric, Ginger. b) Dicot: i) Lauraceae – Cinnamon. ii) Mytraceae – Clove. iii) Piperaceae – Black pepper. iv) Rubiaceae – Coffee. v) Solanaceae – Chilli. vi) Sterculiaceae – Cocoa. 2. On the basis of climatic requirements: (Classification of Horticultural crops) Temperature: a) Temperate Horticultural crops: In temperate regions, the temperature in winter season falls below freezing point. The crops shed their leaves and go into rest. These chilling temperatures help the plants to put forth new growth. Flowering and fruiting starts with the onset of spring. e.g.,  Fruits: Apple, Pear, Almond, Walnut etc.
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   Spices: Saffron,Kalajira, Asafoetida etc.  Vegetables: Cabbage, Cauliflower, European varieties of carrot and radish. These vegetables can be grown in sub-tropical regions, however they require temperate climate for seed production. b) Sub-tropical Horticultural crops: In sub-tropical climate, the summer are hot and dry and winter are less mild. e.g.,  Fruits: Citrus, Guava, Pomegranate, Fig etc.  Spices: Turmeric, Ginger, Onion, Garlic etc.  Vegetables: Tomato, Brinjal, Chilli, Okra, Potato etc. c) Tropical Horticultural crops: The climatic conditions in such areas are hot and humid in summer and mild in winter. e.g.,  Fruits: Mango, Banana, Pineapple, Sapota etc.  Spices: Black pepper, Turmeric, Ginger, Cloves etc.  Plantation crops: Coconut, Arecanut, Cocoa etc.  Vegetables: Tomato, Brinjal, Chilli, Onion etc. 3. Based on the season of growth In India, seasonal or annual vegetables can be classified according to their season of growth. Season of growth is the period in which the climatic conditions are favourable for the growth and production of a crop. (a) Kharif season vegetables: These may also be called rainy season crops. These vegetables require hot and humid climate. The season tentatively starts from 7 June and lasts till 6 October every year. The sowing of seeds may be undertaken from mid-May to late July. Vegetables, like okra, cowpeas, cluster beans, etc., are examples of Kharif vegetables. (b) Rabi or cool season vegetables: These may also be called cool or winter season crops as these vegetables require low temperature for growth. The season tentatively starts from 7 October and lasts till 6 February. The sowing of seeds may be undertaken from mid- September to late October. Vegetables, like peas, radish, carrot, cauliflower, cabbage, knol-khol, leafy vegetables, etc., are examples of Rabi vegetables. (c) Summer or warm season vegetables: The season tentatively starts from 7 February and lasts till 6 June. The sowing of seeds may be undertaken from mid-January to late February. These crops require hot and dry climatic conditions for better growth and maximum production. Cluster bean, musk melon, cucumber, watermelon, etc., are summer season vegetables. 4. Based on plant part used as vegetable (a) Stem and leaves: Cabbage, lettuce, spinach, methi, coriander, amaranthus, etc. (b) Flowers: Broccoli (head ‘flower buds’), cauliflower (curd ‘pre-floral stage’), etc. (c) Fruits: There are various stages where the fruits of vegetable crops can be harvested for consumption, such as • Ripened fruits: Watermelon, musk melon, tomato, etc. • Immature and tender fruits: Cucumber, bottle gourd, bitter gourd, ridge gourd, okra, brinjal, green chilli, cowpea, French beans, dolichos beans, etc. (d) Seeds: Peas, etc. (e) Underground parts of plant • Taproot: Tapering root growing vertically downward, e.g., carrot, radish, etc.
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  • Bulb: Afleshy leaved storage organ in some vegetables sending adventitious roots downward and leaves upward, e.g., onion, garlic, etc. • Tuber: Thick, short and rounded underground stem with modified nodes and buds, e.g., potato, sweet potato, etc. • Rhizome: Underground root-like stem having roots and shoots, e.g., colocasia, ginger, etc. CLIMATE AND SOIL FOR HORTICULTURAL CROPS SOIL REQUIREMENT Soil is a thin outer covering of the earth, directly developed by natural forces acting on natural materials. It is a basic medium for plant growth, supplies nutrients for growing plants. Soil is the home of the plant root and the reservoir for essential nutrients and water for its growth and development. 33.1.1 Types of Soil On the basis of pH, EC and presence of ESP the soil are grouped as (1) Saline (2) Alkaline (3) Saline-alkali (4) Acidic
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  On the basisof sand, silt, and clay soils are grouped (classes). a) Sandy b) Sandy loam c) Loamy d) Silt e) Silt loam f) Sandy clay loam g) Clay loam h) Sandy clay i) Clay etc. Porous aerated and deep soil should be preferred for fruit cultivation. The ideal orchard soil should be at least 1.8 m deep having a uniform texture, well drained, non-saline and fertile. Soils with a poor sub soil stratum should be avoided. Fruit tree will not grow well if there is solid rock or permanent water close to the surface of the soil. Sub soil with a hardpan or pebbles within 120 cm of the surface soil should not be chose. Extreme conditions of top and sub soil namely very heavy (clayey) and very light (highly sandy) should be avoided. Heavy soils are difficult to handle on account of poor drainage while very light soils are infertile because of leaching of nutrients. Medium textured silt loam or fine sandy loam makes good orchard soil. Most fruit plants like slightly acidic to neutral soil reaction (pH 6-7). Some fruit species can some times tolerate little more acidic or alkaline medium but too acidic or too alkaline soil should be avoided.
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  Soils with fluctuatingwater table are not suitable because the water table moves up and reaches the root zone damaging the root hairs. When the water table goes down, the trees with shallow root system struggle for moisture and nutrients causing reduction in growth and vigour of trees. Thus soils having water table depth of less than 3 m are not usually preferred for establishing an orchard. Some fruits, however, such as, Mango, Grape, Lime, Ber, Custard Apple, Avocado and Cashew do well on for wide range of soil type. Ph Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. pH is defined as the negative logarithm of the activity of hydronium ions (H+) in a solution. Acid soils have a pH below 7 and alkaline soils have a pH above 7.
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  Denomination pH range Ultraacidic < 3.5 Extremely acidic 3.5–4.4 Very strongly acidic 4.5–5.0 Strongly acidic 5.1–5.5 Moderately acidic 5.6–6.0 Slightly acidic 6.1–6.5 Neutral 6.6–7.3 Slightly alkaline 7.4–7.8 Moderately alkaline 7.9–8.4 Strongly alkaline 8.5–9.0 Very strongly alkaline > 9.0 Electrical conductivity (EC)  Soil electrical conductivity (EC) is a measure of the amount of salts in soil (salinity of soil). It is an important indicator of soil health.  It affects crop yields, crop suitability, plant nutrient availability, and activity of soil microorganisms which influence key soil processes including the emission of greenhouse gases such as nitrogen oxides, methane, and carbon dioxide.  Excess salts hinder plant growth by affecting the soil-water balance. Soils containing excess salts occur naturally in arid and semiarid climates. Salt levels can increase as a result of cropping, irrigation, and land management.  Although EC does not provide a direct measurement of specific ions or salt compounds, it has been correlated to concentrations of nitrates, potassium, sodium, chloride, sulfate, and ammonia.  For certain non-saline soils, determining EC can be a convenient and economical way to estimate the amount of nitrogen (N) available for plant growth. Climate  Climate is the principal factor controlling plant growth. It refers to the average condition of the atmosphere over along period, where as the term weather is used to describe the current and temporary atmospheric conditions.  For successful growing of horticultural plants, various components of climate like temperature, humidity, wind, light, rainfall, hail and frost should be carefully studied.  Man can not control these environmental factors. It is not possible to make any change in it. But the effect of these factors can be altered.  For these we can take certain steps to increase or decrease its effects. i.e. effect of high or low temperature can be altered, additional moisture can be given, high wind velocity can be reduced by growing wind break around the orchard.
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  Climate of aregion is mainly influenced by the factors viz. a) latitude b) altitude c) topography d) position related to continents and oceans e) large scale atmospheric circulation patters.  Almost all components of the climate influence horticultural crops. All are closely interrelated. The effect of each is modified by others.  All crops have certain natural threshold limits of the climatic components beyond which they do not grow normally, but breeding and selection are gradually extending the threshold for many crops.
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  INFLUENCE OF ENVIRONMENTALFACTORS ON HORTICULTURAL CROP PRODUCTION Temperature  Temperature is one of the most important components of climate. It plays vital role in the production of horticultural crops.  The different activities of plant like growth and development, respiration, photosynthesis, transpiration, uptake of nutrients and water and reproduction (Such as pollen viability, blossom fertilization fruit set etc.), carbohydrate and growth regulators balance, rate of maturation and senescence, and quality, yield and shelf life of the edible products.  The above function of the plant should be well when the temperature at the optimum range.  During high temperature plant does not perform proper functions of growth, where in low temperature physiological activities of the plant are stopped.  According to different temperature range in the tropics, the specific trees are grown in different location e.g. apple, pear, peach, almond are successfully grown in the regions of low temperature known as temperate fruits. In warm winter areas, due to insufficient chilling temperature fruit trees fail to complete their physiological rest period or meeting their chilling requirement. As a consequence, buds remain dormant, and leave and blossoms do not appear on the trees in the following spring. For this reason temperate fruit like apple, apricot, pear and plums are not considered suitable for tropical or subtropical regions. For tropical and sub tropical fruits the minimum temperature must be within the limit of tolerance of the fruit species.  The fruit grown in tropical and sub tropical climate is known as tropical fruit and sub tropical fruits. Mango, chiku, papaya, banana are successfully grown in high temperature regions also known as tropical fruits.  The plant performs well in optimum temperature range. The activities of the plant are affected by very high or very low temperature. The temperature range for plant is Minimum 4.5° to 6.5° C (40° - 43° F) Optimum 24° to 27° C (75° - 85° F) Maximum 29.5° to 45.4° C (85° - 114° F) Effect of low temperature The low temperature influenced adversely on plant. There are many effects of low temperature i.e.  Desiccation: Imbalance between absorption rate and transpiration rate.  Chilling injury: There is a disturbance in metabolic and physiological process.  Freezing injury: It is termed as under cooling protoplasm coagulation. Humidity (moisture) and frost  The atmospheric humidity plays a vital role in deciding the amount of moisture needed to produce a fruit crops.  In hot, dry weather enormous amount of water is lost through transpiration.
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   If theatmosphere is humid, even though hot, the amount is much smaller and thus a site in humid belt needs less irrigation.  High humidity combined with high temperature also promotes rapid growth. Higher yield but increase incidence of pests and diseases.  The water requirement of plant also depends on humidity but generally requirement of water is differed as per different plant species. e.g. to produce 1 kg dry matter pine tree require 25 liters. of water, apple required 250 liters, Lucern required 500 liters of water.  The plant gets water from soil, but there are many factors affecting it. i.e. (a) amount of water in the soil (b) availability of water is also depends on texture and structure of soil (c) water absorbing area of the tree.  The water is lost from the plant through transpiration by leaves. Transpiration depends on humidity, temperature, wind, light etc. is necessary to maintain the health of plant by maintaining the balance between uptake and loss of water. Light  Light is an electro magnetic radiation which is a form of kinetic energy. It comes from the sun to the earth as discrete particles called quanta or photons.  Light is one of the most important affecting plant life. It is an integral part of the photosynthetic reaction in that it provides the energy for the combination of carbon dioxide (CO2) and water (H2O) in the green cells having chlorophyll for the formation of carbohydrates with release of oxygen.
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   The performanceof crop of growth of plants is influenced by three aspects of light (a) quantity of light (b) intensity of light (c) duration of light. a) Light intensity:  Light intensity refers to the number of photons falling on a given area or to the total amount of light which plants receive; the intensity of light varies with the day, season, distance of equator, dust particles and water vapour in atmosphere, slope of the land and elevation.  Symptoms associated with low light intensity are decrease in rate of photosynthesis with normal rates of respiration, decrease supplies of carbohydrates for growth and yield, leaf tips become discoloured, leaves and bud drop, leaves and flowers become light in colour.  Due to high light intensity, the plant wilts and light coloured leaves may become gray in colour due to reduction in chlorophyll, the rate of photosynthesis is lowered down while respiration continues. All above reasons cause low yields. b) Quality of light:  Refers to the length of the waves. The visible part of spectrum of electromagnetic radiation ranges from wavelength 390 to 730 µm (nanometer). It is also called photosynthetically active radiation.  In general, red and blue light produce a greater dry weight. Green light inhibits plant growth. Red light promotes seed germination, growth and flower bud formation in long day short night plant.  Photosynthesis is more in the red region. In apple the blue violet region is more important for the development of red pigments and colour. c) Duration of light: Refers to the period for which light is available. Duration of light required is also known as photoperiod. Photoperiodism: Response of plant to length daily exposure to the light is known as photoperiodism or relation of the time of flowering formation of tubers, fleshy roots etc. to the daily exposure length of period of light.
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  The plants aremainly grouped into three according to duration of light required. 1. Long day plant: Those plants which require 16 hours or more of daily exposure of light and short night 8-10 hours of dark period for induction of flowering e.g. radish, cauliflower, cabbage, carrot, spinach. 2. Short day plant: Those plants which require 12 hours or less of daily exposure of light and long night 10 to 14 hours dark period for induction of flowering. e.g. strawberry, potato, sweet potato, chrysanthemum, cosmos, poinsettia etc. 3. Day neutral plants: Day neutral plants are those plants in which flowering are induced irrespective of duration of light. Such plants are also known as photo insensitive plants. e.g. tomato, chilli, okra, carnation, dianthus, African violet. 4. Intermediate plants: Those plants which require definite period of daily exposure of light. e.g. wild kidney bean, Indian grass, broom grass. Rainfall  This is a very important factor for horticultural crops, and if a garden or orchard is to be established in a new area it is essential that the pattern of rainfall in the region be studied before any decision is taken concerning the types of crop to be cultivated.  Well-distributed and consistent rainfall is always desirable for and ideal orchard site.  Rain at the time of flowering is not suitable, because most of tropical fruit crops are sensitive to rain. Wind  The effect of high wind on crops can be appreciable. Complete physical destruction may result because little can stand against winds of the order of 100 km/hour, even large trees become uprooted.  Some crops have quite low damage even due to high wind speed. In many regions high winds can destroy the flowers, fruits etc.  Wind breaks can help reduce this problem. The wind break trees, like saru, eucalyptus, Ingadulsis are growing around the orchard for protection.