Plant-disease-and-control.pptx

Plant Diseases and Its Control The first and best defense against plant diseases is a healthy plant, which is the main task of an accomplished gardener. Preventing and managing plant disease begins even before planting, with site preparation and plant selection. When a plant does not look nor...

Plant Diseases and Its Control The first and best defense against plant diseases is a healthy plant, which is the main task of an accomplished gardener. Preventing and managing plant disease begins even before planting, with site preparation and plant selection. When a plant does not look normal, or as expected, a gardener may assume that the plant is diseased and control measures are needed. To properly diagnose plant problems, the gardener needs to have background knowledge about the plant, the current environment, and the typical diseases or other problems to which the plant is susceptible. Diseases are the most difficult type of plant injury to diagnose and manage. 1. Plant disease is any condition that does not allow the plant to function normally. 2. Plant Disease it is a malfunction in the plant in response to continuous irritation by an infectious causal agent, also known as a pathogen. Plant diseases often provide helpful clues to the underlying problems that made a plant susceptible. These problems might  poor site selection  nutrient imbalance  water stress  improper mulching  irrigation or pruning practices  A plant disease can cause many types of symptoms that may affect the plant's ability to yield, reproduce or grow properly.  the causal agents of plant disease are biotic, or living 4  Plant Diseases are caused by:  Noninfectious plant diseases  Infectious plant diseases What are Noninfectious plant disease?. Noninfectious disease cannot reproduce and spread from plant to plant  caused by nonliving agents or cultural and environmental factors such as drought, soil compaction, hail, wind, toxic chemicals, nutrient deficiency, and temperature or moisture extremes  Symptoms - wilting, stunting, and yellowing of leaves  may appear suddenly on a plant with a non-infectious disease.  few noninfectious diseases can be corrected or avoided (nutrient deficiency symptoms) 6 An infectious plant disease is caused by an agent that attacks and feeds on the host plant. The disease-causing agent is called a pathogen. Fungi, bacteria, and viruses are pathogens for vegetable crops. Pathogens are spread from diseased plants to healthy plants by wind, rain, soil, people, machinery and insects. 7 Infectious plant disease  Fungi are the largest and most familiar group of plant pathogens. The best known fungi are mushrooms and yeast  Bacteria are very small, microscopic, one-celled organisms. Some bacteria are harmful to humans and animals because they cause diseases such as pneumonia, tuberculosis, typhoid fever, and anthrax. Bacteria also cause diseases in plants but most bacteria are harmless or beneficial (for example, the nitrogen-fixing bacteria of legumes).  A virus is a very small non-living pathogen that cannot reproduce by itself. Viruses multiply by tricking the host cells into making more viruses. They are most familiar to us as the cause of human and animal diseases, such as polio, influenza, chickenpox, and warts. Viruses can also cause diseases in plants 8  DISEASE MANAGEMENT Cultural Control Biological Control Chemical Control 9  Cultural Control Crop rotation Tillage Row spacing Variety selection Seed quality 10 Thanks! 11