Things to Know When analysing a disease or pest cycle you must understand the following.
Where does each stage of the life cycle occurs - in the soil, on the leaf, in the stem?
How long does each stage last for?
How many generations are there in a season or time frame?
What seasonal factors are involved - do the weed seeds germinate in spring or autumn? Do the winged male insect pests hatch in wet or dry weather?
What is the rate of spread? How fast does the weed, pest or disease population increase and spread? This will tell you how much time you have after you identify them at a certain level to control them effectively and efficiently.
Why is this important? This information will enable you to:
time your treatments so they are effective
place your treatments so they affect only the problem
apply preventative, protective treatments
know whether certain practices should be applied - such as destroying debris, composting leaves, treating seed and water supplies, replacing growing media.