There are two general types of dispersal models. What are they? Also, describe the differences between these two models.

Dispersal models are similar to models for disease progress over time. With that being said, what is the significant difference between these two modeling approaches?

Under what situation will an Exponential model be more appropriate? A Power model?

For a polycyclic pathogen, dispersal (or disease) gradients may be made over the course of a growing season. What typically happens to the gradient over time? Which model has a link to the Exponential model for these situations? The Power model?

What are some of the statistics that may be used for determining a model's goodness-of-fit? What R function enables an examination of these statistics?

What are the three steps involved for fungal dispersal?

Why is modeling dispersal important for studying plant pathogens and plant diseases? What are the two most important mechanisms for fungal dispersal?

What would be the difference in the disease gradient between data modeled by y=19*exp(-0.1x) and y= 19*exp((-0.5x)? Would it be reasonable to compare the disease gradients associated with these 2 equations?

What are the five primary mechanisms for nematode dispersal? Describe for one of the mechanisms a method to reduce the likelihood of nematode dispersal.

Would you expect a random distribution of infected plants if the source of inoculum was infected seeds? Aerially dispersed propagules? Inoculum from adjacent fields? Explain your reasoning.