plantdisease

Plant disease refers to impairment of plant health caused by biotic agents such as fungi, bacteria, viruses, oomycetes, nematodes, or parasitic plants, as well as by abiotic factors including drought, nutrient deficiencies, salinity, waterlogging, frost, and chemical injury. Diseases disrupt growth, reduce yields, and can affect quality.

Biotic diseases arise from pathogens that invade plant tissues, reproduce, and spread within and between plants. Major groups include fungi, bacteria, viruses, oomycetes, nematodes, and parasitic plants. Symptoms vary widely and may include lesions, chlorosis, cankers, wilting, necrosis, dwarfing, or distortion.

Diagnosis combines field observation with laboratory tests such as microscopy, culture, and molecular methods to identify the causal agent. Accurate identification is essential for selecting effective control measures and avoiding unnecessary or harmful treatments.

Pathogen spread occurs through wind, rain splash, vectors, contaminated equipment, seed or soil, and irrigation water. Environmental conditions like temperature, humidity, and rainfall strongly influence disease development. Climate change can alter geographic ranges and seasonal timing of many plant diseases.

Management relies on integrated approaches that mix cultural practices, resistant varieties, accurate timing, and judicious use of pesticides or biological controls. Strategies include crop rotation, sanitation, proper spacing and irrigation, pest forecasting, and adoption of resistant cultivars and beneficial microbes.

Economic impact of plant disease can be substantial, reducing yields, quality, and market value and threatening food security in vulnerable regions. Ongoing research aims to improve detection, resistance breeding, diagnostics, and sustainable disease management.