Plant Diseases. A disease is a physiological disorder and structural abnormality which is dangerous to the plant or part of the plant.
How Diseases Spread From Crop To Crop
Through wind or air currents that blow disease spores from infected plants to healthy ones
Through rain water or rain splash that disperses off infected soil from a diseased plant to a healthy crop
Through contact of plants i.e infected and healthy ones
Planting of the infected planting materials e.g seeds
Through use of garden tools that were used on infected crops e.g knives,pangas,hoes etc
Through sucking pests which inject infected saliva into a healthy plant e.g aphids
Through use of mulches that were previously infected
Through irrigation water that is infected by disease pathogens e.g bacteria,fungi and viruses
Use of organic manure e.g FYM,Green manure that is also infected by disease.
General Methods that can be used to control crop Diseases
Planting of resistat or tolerant crop varieties that can withstand disease attacks.
Legislation to restrict movement of infected planting materials from one place to another
Weeding to remove plants tat can act as alternate hosts of disease causing organisms
Carrying out a good crop rotation to prevent build up of diseases to crops
Proper land drainage of the soil surface to prevent water borne diseases
Spraying of crops with recommended chemicals to control crop diseases
Seed dressing to destroy spores that may be hidden on seeds
Rogueing i.e removal of diseased plants or plant parts and destroyed by burning
Soil treatment/sterilization should be done to kill spores of diseases
Early planting or timely planting in order to escape disease build up
Use of diease free planting materials to prevent the spread of diseases