ECOSYSTEM
An ecosystem is a biological system or environment where organisms interact with each other. The study of ecosystem is called an ECOLOGY
The interactions between organisms
Ecologically organisms must interact with one another. And some of these interactions or relationships are beneficial to all the organisms involved. While, in some only one party benefits from the relationship. However, in some relationships there is even harm involve. Thus, these lead to two different phenomenon known as dependency and interdependency, this relationship is otherwise called symbiosis.
Dependency
This is a relationship that occur naturally in which only one organism that is involved, benefits from the relationship. But the other may either be harmed or left without any benefit at all.
Dependency relationships
The types of relationships under dependency may include.
1. Predatism
2. Saprophytism
3. Parasitism
Interdependency
Interdependency on the other hand is the relationship in which all the organisms involved are benefited in most cases. And without harming each other e.g. Mutualism.
Now it is clear that not all of these relationships are harmful to our crops perhaps there are some that are extremely beneficial. And can help us in our agricultural productions, hence to control pest and diseases do not necessarily mean to destroy all the organisms in a farm, but to control them and reduce their population so that they will not reach the level of causing economic injury.
Economic injury level
Economic injury level (EIL) is the fewest amount or population of pests that is capable of causing economic loss.
Therefore, Economic injury level is very important in determining the level at which the pest need to be stoped. For example when a farmer calculate the EIL he or she will know if it is time to use pesticide. And which amount to use.
Formula to calculate economic injury level
Below is the formula to calculate the economic injury level.
EIL = (C x N)/(V x I)
Where;
EIL = Economic injury level, C = cost of management , N = number of pest that cause loss, V = price of commodity and I = injury cause by a single pest.
