Extreme drought

While not a living pathogen, drought acts as a catalyst for non-infectious diseases, such as physiological wilting and tissue necrosis.

Under drought conditions, plants rapidly close their stomata to prevent transpiration, which inadvertently halts photosynthesis and limits carbon fixation.

Detection is based on analyzing soil moisture levels in conjunction with the visible stress responses of the vegetation in the field.

The severity of the impact is determined by the duration of the moisture deficit and the specific growth stage of the crop at the time of onset.

Extreme drought damages all major crop types, including cereals, maize, sunflowers, and legumes, by impairing nutrient uptake and transport.

In cereals, severe water stress during the grain-filling stage results in shriveled grains and a significant reduction in overall yield quantity and quality.

Maize and sunflowers show inhibited development of reproductive organs, which often leads to barren stalks or poorly filled heads.

Vegetable crops under drought stress exhibit stunted growth, physical deformities, and decreased nutritional content, making them unfit for market.

Long-term drought weakens the natural immune system of trees and perennial plants, leaving them susceptible to secondary infections and pest outbreaks.

Extreme drought most commonly occurs during the summer months when high temperatures accelerate soil moisture evaporation and plant water usage.

Spring droughts are particularly dangerous as they prevent early-stage growth and hinder the establishment of deep, resilient root systems.

Summer heatwaves combined with dry winds can cause rapid desiccation of entire fields within a very short period of time.

Autumn droughts create harsh conditions for winter crops, impeding proper germination and the ability of seedlings to harden before winter dormancy.

Climate change has increased the frequency of these events, making it difficult for farmers to predict and manage potential water shortages.

The first sign of drought is temporary wilting during the hottest part of the day, indicating that transpiration exceeds water absorption capacity.

Leaf curling, yellowing (chlorosis), and tip burning follow as the plant attempts to minimize surface area exposed to the sun and dry wind.

A damaged root system becomes less functional, with root hairs dying off and the plant losing its structural rigidity.

Phenological development becomes visibly delayed compared to healthy control areas, with plants showing premature maturity or stunted size.

The presence of opportunistic secondary pests, such as spider mites or aphids, often signals that the plant is already severely weakened by water stress.

The primary control strategy involves selecting drought-tolerant genotypes that possess improved water-use efficiency and deep rooting traits.

Adopting sustainable agricultural practices like conservation tillage helps maintain soil structure and improves moisture retention capabilities.

Proper nutrient management, particularly the use of potassium fertilizers, strengthens plant cells and enhances their ability to maintain turgor pressure.

• Implementation of drip irrigation systems to optimize water delivery.
• Application of soil conditioners and organic mulches to reduce evaporation.
• Adjustment of plant density to minimize competition for limited water resources.

Establishing windbreaks around agricultural land helps reduce evapotranspiration rates and protects crops from the drying effects of hot, dry winds.