What is drought stress in plants?
Generally, drought stress occurs when the available soil-water becomes scanty and atmospheric conditions cause continuous loss of water by transpiration or evaporation. Water deficit is one of the major abiotic stresses, which adversely affects crop growth and yield. Drought stress is an abiotic disorder that causes wilt, growth reduction, early onset of fall colors, and premature leaf drop in trees and shrubs. It occurs when the amount of moisture in the soil no longer meets the needs of the plant.In response to drought stress, plants activate their drought response mechanisms, such as morphological and structural changes, expression of drought-resistant genes, synthesis of hormones, and osmotic regulatory substances to alleviate drought stress.The first evidence of drought is usually seen in records of rainfall. Within a short period of time, the amount of moisture in soils can begin to decrease. The effects of a drought on flow in streams and reservoirs may not be noticed for several weeks or months.The Short Answer A drought is caused by drier than normal conditions that can eventually lead to water supply problems. Really hot temperatures can make a drought worse by evaporating moisture from the soil.
What is another name for drought stress?
There are several terms that signify a stress situation for plants in connection with water supply. These are soil moisture stress, drought, moisture stress, drought stress, water shortage and water stress. They are sometimes used interchangeably as synonyms. Water stress is defined as a condition in which the demand for freshwater exceeds its availability in a specific region or time, leading to environmental, social, and economic penalties.Observed effects of this stress include: Dehydration and Hunger: The lack of water is itself a significant issue for human health, but water shortages often lead to failed crops and livestock death as well.Though not immediately disastrous, prolonged plant stress can cause a host of different issues for your plants, including growth deficiencies, permanent damage, and death.Such as drought (water stress), flood (waterlogging), salinity (toxicity), temperatures, winds, and soil compaction. Chemical Plant Stress: The stress imposed by the chemical state of the physical environment, such as air pollution, pesticides, soil pH, and water.However, they do not refer to the same thing: while drought is a meteorological phenomenon, drought stress (also called water deficit stress) refers to the condition of a plant lacking water. While drought occurs after many days without rainfall, drought stress can arise rapidly in plants, and have an impact on yields.
What are the different types of drought stress?
There are several types of drought: (i) meteorological, caused by a long-term deficit of rainfall; (ii) hydrological, caused by a deficit in river flow; (iii) pedological, attributed to a shortage of soil-water storage (green water) in the profile or soil solum (surface and subsurface layers that have the same history . Drought stress resulted the reduction of crop plant productivity by reducing the leaf size, stem extension and root proliferation, disturbing plant water and nutrient relations, and inhibiting water-use efficiency.Depending upon how severe the conditions get and how long they last, drought can devastate crops, dry out forests, reduce food and water available for wildlife and livestock, restrict recreational activities, and stress businesses and economies.Droughts can be broadly classified into four main types based on their causes – meteorological, hydrological, agricultural and socioeconomic.The many different drought impacts are often grouped as “economic,” “environmental,” and “social” impacts. All of these impacts must be considered in planning for and responding to drought conditions.Plants in their natural habitats adapt to drought stress in the environment through a variety of mechanisms, ranging from transient responses to low soil moisture to major survival mechanisms of escape by early flowering in absence of seasonal rainfall.
What is the difference between drought stress and water stress?
Water-deficit stress defined as a situation in which plant water potential and turgor are reduced enough to meet with normal functions. While drought stress occurs when the demand of plants exceeds the supply by (rainfall or irrigation) at any stage of plant growth. Any unfavorable condition or substance that affects or blocks a plant’s metabolism, growth, or development is regarded as stress. Vegetation stress can be induced by various natural and anthropogenic stress factors.
What is the best definition of drought?
Drought is generally defined as “a deficiency of precipitation over an extended period of time (usually a season or more), resulting in a water shortage. If a weather pattern that results in a precipitation deficit lasts for a few weeks or months, it is considered short-term drought. If the pattern and precipitation deficits last for more than six months, it is typically considered long-term drought.Drought can develop quickly and last only for a matter of weeks, exacerbated by extreme heat and/or wind, but more commonly drought can persist for months or years.Food-borne diseases linked to droughts include cholera, dysentery, salmonella and hepatitis A and E. But any food-borne pathogen can be a risk during times of water scarcity.The most common sign of drought is wilting and browning of vegetation, particularly in sensitive species. This can be accompanied by cracked soil and reduced water levels in local bodies.Drought can lead to decreased water quantity and quality, increased incidence of illness or disease, increased mortality rates, and adverse mental health outcomes as livelihoods are challenged. During drought conditions, fuels for wildfire, such as grasses and trees, can dry out and become more flammable.
What does drought stress look like?
Common signs of drought stress include: Grayish cast to leaves. Leaf curling or rolling. Drooping leaders on conifers. Leaf drop. Trees can sometimes lose all their leaves to drought and recover; sometimes not. If a tree is severely stressed and drops all of its leaves, it may be unable to produce enough photosynthates to properly harden off and survive the up-coming winter.A reduction in the number of leaves per plant, a reduction in leaf size, and an increase in leaf senescence are only a few of the detrimental effects of drought stress during the vegetative period [150,151,152,153]. Another important physiological response that occurs in response to water stress is leaf rolling.