Trade Diploma in Agriculture Trimester II Year 2014 PPA 401 Lecture Tutorial Questions (T 6) Q.1 What is integrated plant disease management? INTEGRATED PLANT DISEASE MANAGEMENT (IDM) – Integrated plant disease management can be defined as a decision-based process involving coordinated
use of multiple tactics for optimizing the control of pathogen in an ecologically and economically. The
implications are:
Simultaneous management of multiple pathogens
Regular monitoring of pathogen effects, and their natural enemies and antagonists as well
Use of economic or treatment thresholds when applying chemicals
Integrated use of multiple, suppressive tactics.
Principles of Plant Disease Control
1. Avoidance—prevents disease by selecting a time of the year or a site where there is no
inoculum or where the environment is not favorable for infection.
2. Exclusion—prevents the introduction of inoculum.
3. Eradication—eliminates, destroy, or inactivate the inoculum.
4. Protection—prevents infection by means of a toxicant or some other barrier to infection.
5. Resistance—utilizes cultivars that are resistant to or tolerant of infection.
6. Therapy—cure plants that are already infected
Q2. What is biological control? Why we go for biological control? Biological control is a component of an integrated pest management strategy. It is defined as the reduction of pest populations by natural enemies and typically involves an active human role. Keep in mind that all insect species are also suppressed by naturally occurring organisms and environmental factors, with no human input. This is frequently referred to as natural control. This guide emphasizes the biological control of insects but biological control of weeds and plant diseases is also included. Natural enemies of insect pests, also known as biological control agents, include predators, parasitoids, and pathogens. Biological control of weeds includes insects and pathogens. Biological control agents of plant diseases are most often referred to as antagonists. A high reproductive rate is important so that populations of the natural enemy can rapidly increase when hosts are available. The natural enemy must be effective at searching for its host and it should be searching for only one or a few host species. No natural enemy has all these attributes, but those with several characteristics will be more important in helping maintain pest populations. Trade Diploma in Agriculture Trimester II Year 2014 PPA 401 Lecture Tutorial Questions (T 6) Q 3. Why Consider Biological Control? • There are many problems with over‐reliance on pesticides – Environmental hazards – Emergence of secondary pests – Pesticide resistance _ Food safety problem • Biological control is considered environmentally safe and “friendly” • Effective — there have been hundreds of successes • Cost‐effective — there is great potential return for small investment Q3 What are the basic principles behind biological control? Q4 Name some bioagents used in biological control? Q 4 How Can Biological Control Reduce Pests? • Pest‐ Organism out of place • Target pest‐ Organism you want to control • Injury‐ Physical result of pest presence (eg. defoliation) • Damage‐ When Injury becomes intolerable (yield loss, ugly plants, etc.) • Abundance‐ Number of insects present at a point in time • Economic Injury Level‐ Density of pests that causes economic damage Prevention • Cause mortality early against target species • Intervene before pest status is achieved • Requires early monitoring and intervention • Useful against regular or predictable pests • Information‐intensive • Requires understanding system very well