If the orange tree in exercise 2 was in an and or salt prone environment, emitter spacing would look something like this,
The wetted patterns under the soil surface would overlap near the trunk and cover approximately 50-60% of the plant area.
In a shrub bed application the plant area may often be the spacing between plants and rows of plants. Emitter spacing for each plant area may be dictated by the direction the tubing or pipe runs through the bed. (See illustration below)
The same six shrubs can be irrigated by a single emitter with multi-outlets as shown below. The emitter outlets each have a distribution tube carrying the water to the points for proper spacing.
Avoid placing the emitter right at or against the plant stem or trunk. The soil immediately beneath the emitter is in a wet zone. As the water moves away from the emitter, it spreads out to the moisture level desired by the roots.
An emitter against the trunk or stem can produce a continually saturated condition which is not healthful for the plant.