The number of rings in a tree trunk can be used to estimate the age of the tree, and tree age, scion, nutrition and other factors that affect the overall health of the tree could affect rootstock resistance or susceptibility to Phytophthora. Given these facts, what can be checked along with nutrition and scion that can help determine health of a tree. among the following options:
- the number of rings
 - Temperature
 - Exfoliation
 - it needs them
 - organic molecules
 - aerobic capacity
 - biodiversity
 - looseness of dirt or compost


 

 the number of rings        