User:TysonM343/Horticulture

Types

 * Interiorscaping: the science and art of using indoor plants. It has an important role in house, hotel, office and mall decor.
 * Spices Crops Culture: deals with the cultivation of spice crops which include pepper, nutmeg and cardamom.
 * Plantation Crops Culture: deals with the plantation crop growth.
 * Medicinal and Aromatic Plants Culture: deals with growing and handling of medicinal and aromatic plants.
 * Post-Harvest Management: deals with the post-harvest handling, processing and marketing of horticultural products. It also includes grading, packaging and storage.

Propagation
Plant propagation in horticulture is the process in which the reproduction of a species is controlled to fit the desire of the horticulturalist. The practice is primarily used to increase the frequency of reproduction, producing larger numbers of a species while preserving wanted genetic and morphological characteristics. Propagation can be done using sexual or asexual methods. In sexual propagation seeds are used, while tubers, corms, and techniques such as cutting, layering, grafting, and tissue culture is used for asexual propagation. Sexual, or seed propagation is a common method for self-pollinating and cross-pollinating plants. If stored in a cool, dry environment, seeds can last years and are a space efficient way to store plants and do not transmit viruses. However, seeds do not preserve genetic homogeneity and depending on the species, can take a long time to grow into a mature plant. Scarification of seeds may be required for germination if they have a tough seed coat.

Asexual, or vegetative propagation relies on the regeneration of plant tissues. Asexual propagation preserves genetic and morphological characteristics and allows for the propagation of species that do not produce seeds. However, reducing genetic diversity means every individual produced is susceptible to the same diseases.

Asexual propagation techniques include the use of:


 * Apomictic seeds
 * Vegetative structures capable of regenerating entire plants such as tubers, corms, and runners.
 * Layering: propagation by manipulating the plant into regenerating missing parts, the part being regenerated is attached to the original plant. Roots and shoots can be used.
 * Cuttings: like layering, except the regenerated part is free from the original plant. Roots, stems, or leaves can be used.
 * Grafting: propagation using natural regeneration to fuse two plant parts with callus tissue. The plant part containing the root is the stock, the part being grafted unto the stock is the scion.
 * Budding: when the scion of a graft is a single plant bud.
 * Tissue culture: propagation involving placing plant tissue, which can be embryos, shoot tips, and callus, onto a substrate supplying food (sugars), inorganic and organic compounds, and growth regulators catered to the type of tissue used.
 * Embryo culture: used for species that do not grow an embryo within their fruit.
 * Shoot tip culture: useful for producing plants without the risk of disease.
 * Callus tissue culture: an experimental method of propagation by which callus tissue is grown and manipulated to differentiate into other plant organ tissue. This method is used in scientific research but is currently considered impractical for horticulture.

Controlling Environmental Variables
Environmental control is involved at all scales of horticulture, although the extensiveness of control varies between hobbyist and commercial horticulture. Basic control involves planting  location, sunlight availability, water availability, latitude, and longitude.

More intensive control can involve the use of cold frames, greenhouses, and shade houses. Cold frames provide an enclosed environment, they are built close to the ground and with a top made of glass or plastic. The glass or plastic allows sunlight into the frame during the day and prevents heat loss that would have been lost as long-wave radiation at night. This allows plants to start to be grown before the growing season starts. Greenhouses are similar in function, but are larger in construction and heated with an external source, such as steam. They can be built out of glass, although they are now primarily made from plastic sheets. More expensive and modern greenhouses can include temperature control through shade and light control or air-conditioning as well as automatic watering. Shade houses provide shading to limit water loss by evapotranspiration.

Temperature control can be done through a variety of methods. Covering plants with plastic in the form of cones, called hot caps, or tunnels can have the same effect as greenhouses. Mulching is also an effective method to protect plants from frost. Other frost prevention methods include the use of wind machines, heaters, and sprinklers.

Light control by artificially increasing or decreasing the effective length of day through the use of fluorescent lights determines the time in which photosynthesis can occur. This increases the time in which the plant can grow and develop. Controlling the amount of light also controls which plants flower, lengthening the day encourages the flowering of long-day plants and discourages the flowering of short-day plants.

Soil management methods include the use of planned crop rotation to prevent the degradation of soils that are seen in monocultures (need ref), applying fertilisers, and soil analysis.

Water management methods involve employing irrigation and drainage systems, controlling soil moisture to the needs of the species. Methods of irrigation include surface irrigation, sprinkler irrigation, subirrigation, and trickle irrigation. Volume of water, pressure, and frequency are changed to optimise the growing environment. On a small scale watering can be done manually.

Plant Selection
When selecting plants to cultivate, a horticulturist may consider plant aspects based on their intended use and can include plant morphology, rarity, and utility.

Pre-Plant Bed Preparation
Before planting, plant beds are weeded, extra mulch is removed, fertilizers or other soil enrichment is added, the bed is tilled, and the irrigation system is tested.

Adding Plants
If transplanting plants from a pot to a soil bed, plants are planted at the same depth as the pot and are spaced as to not crowd the plants.

Pruning
Pruning has multiple functions. If growing shrubs, pruning overgrowth helps preserve the shape. Pruning can also increase the amount of flower buds on some species of flowering plants.

Mulching
Mulching is the process of applying a layer of mulch on top of the soil layer of a garden. Mulch is a natural weed suppressant, conserves moisture, and helps in moderating the soil temperature. There are different types of mulch and includes leaf and bark substrates.

Weed Management
Weeds can be suppressed and managed through techniques such as mulching, selecting species that reduce weeds, and using cultural techniques.

Emerging Technology
Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR/Cas9) has recently gained recognition as a highly efficient, simplified, precise, and low cost method of altering the genomes of species. Since 2013, CRISPR has been used to enhance a variety of species of grains, fruits, and vegetables. Crops are modified to increase their resistance to biotic and abiotic stressors such as parasites, disease, and drought as well as increase yield, nutrition, and flavour. Additionally, CRISPR has been used to edit undesirable traits, for example, reducing the browning and production of toxic and bitter substances of potatoes. CRISPR has also been employed to solve issues of low pollination rates and low fruit yield common in greenhouses.

Abiotic Stresses
Commercial horticulture is required to support a rapidly growing population with demands for its products. Due to global climate change, extremes in temperatures, strength of precipitation events, flood frequency, and drought length and frequency are increasing. Together with other abiotic stressors such salinity, heavy metal toxicity, UV damage, and air pollution stressful environments are created for crop production as evapotranspiration is increased, soils are degraded of their nutrients, and oxygen levels are depleted, resulting in up to a 70% loss in crop yield.

Biotic Stresses
Living organisms such as bacteria, viruses, fungi, parasites, insects, weeds and native plants are sources of biotics stresses and can deprive the host of its nutrients. Plants respond to these stresses using defence mechanisms such as morphological and structural barriers, chemical compounds, proteins, enzymes and hormones. The impact of biotic stresses can be prevented using practices such as incorporate tilling, spraying or Integrated Pest Management (IPM).

Transportation
After harvest, horticultural crops are sold commercially. Loading and in-transit conditions are a challenge to maintain the quality of the products. Distance, transport time and transport methods are factors that need to be considered to minimise bruising and damage to horticultural goods.

Harvest Management
Care is required to reduce damages and losses to horticultural crops during harvest. Compression forces occur during harvesting, and horticultural goods can be hit in a series of impacts during transport and packhouse operations. Different techniques are used to minimise mechanical injuries and woundings to plants such as:


 * Manual harvesting: This is the process of harvesting horticultural crops by hand. Fruits, such as apples, pears and peaches, can be harvested by clippers
 * Sanitation: Harvest bags, crates, clippers and other equipment must be cleaned prior to harvest.