Horticulture

Horticulture is the art and science of growing ornamental plants, fruits, vegetables, flowers, trees and shrubs.

Horticulture is commonly associated with the more professional and technical aspects of plant cultivation on a smaller and more controlled scale than agronomy.

For each of these, there are various professions, aspects, tools used and associated challenges; Each requiring highly specialized skills and knowledge of the horticulturist.

Horticulture emerged as a distinct field from agriculture when humans sought to cultivate plants for pleasure on a smaller scale rather than exclusively for sustenance.

Emerging technologies are moving the industry forward, especially in the alteration of plants to be more resistant to parasites, disease and drought.

Mesoamerican cultures focused on cultivating crops on a small scale, such as the milpa or maize field, around their dwellings or in specialized plots which were visited occasionally during migrations from one area to the next.

[13] In Central America, the Maya involved augmentation of the forest with useful trees such as papaya, avocado, cacao, ceiba and sapodilla.

Environmental factors affecting plant development include temperature, light, water, soil pH, nutrient availability, weather, humidity, elevation, terrain, and micro-climate.

Covering plants with plastic in the form of cones called hot caps, or tunnels, can help to manipulate the surrounding temperature.

[19] Water management methods involve employing irrigation and drainage systems and controlling soil moisture to the needs of the species.

Growers within a greenhouse setting will often opt for a soilless mix which does not include any actual components of naturally occurring soil.

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.

Together with other abiotic stressors such as salinity, heavy metal toxicity, UV damage, and air pollution, stressful environments are created for crop production.

This is extrapolated as evapotranspiration is increased, soils are degraded of nutrients, and oxygen levels are depleted, resulting in up to a 70% loss in crop yield.

Living organisms such as bacteria, viruses, fungi, parasites, insects, weeds and native plants are sources of biotic stresses and can deprive the host of nutrients.

[21] Plants respond to these stresses using defence mechanisms such as morphological and structural barriers, chemical compounds, proteins, enzymes and hormones.

[22] The impact of biotic stresses can be prevented using practices such as incorporate tilling, spraying or Integrated Pest Management (IPM).

[24] 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 minimize mechanical injuries and wounding to plants such as:[25] Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) has recently gained recognition as a highly efficient, simplified, precise, and low-cost method of altering the genomes of species.

[27] Additionally, CRISPR has been used to edit undesirable traits, for example, reducing the browning and production of toxic and bitter substances of potatoes.

As compared to genetically modified organisms (GMO), CRISPR does not add any alien DNA to the plant's genes.

A horticulture student tending to plants in a garden in Lawrenceville, Georgia , March 2015
The Rock Garden, Leonardslee Gardens
Flower seedlings at a market in Breda , Netherlands