What facts about tangerines does Paul learn the first time he visits the groves with Luis?

In Edward Bloor's novel Tangerine, the main character, Paul, visits Luis Cruz's family's tangerine grove and learns many things on that first visit. 

Paul learns that Luis's family grows Cleopatra tangerines in their grove, and has sold the fruit to citrus packers and juice companies for forty-five years. 

Next, Luis takes Paul to the nursery, where the family grows trees to sell to farmers. He learns that the trunk and roots of a tree are...

In Edward Bloor's novel Tangerine, the main character, Paul, visits Luis Cruz's family's tangerine grove and learns many things on that first visit. 

Paul learns that Luis's family grows Cleopatra tangerines in their grove, and has sold the fruit to citrus packers and juice companies for forty-five years. 

Next, Luis takes Paul to the nursery, where the family grows trees to sell to farmers. He learns that the trunk and roots of a tree are called the rough stock. Paul learns that the trees in the nursery all start out as rough lemon trees. Using the rough lemon tree, the family cuts a slit in a branch and inserts a bud. This bud will reproduce whatever type of citrus it is: orange, tangerine, lemon, lime, grapefruit. This makes it possible for different types of fruit to be growing on the same tree. Here is what Luis teaches Paul:

"'The new bud that we grafted onto the rootstock is called a scion. The word scion means, like, a child or descendent of the tree.

Luis pointed his arm back to the tall trees. 'Check this out: a scion can be any type of citrus that you want--orange, grapefruit, lemon, lime--and they can all be growing on the same tree at the same time! That means that on one little tree, you could have a branch of white grapefruit, kumquats, and a branch of green limes, like some kind of Frakenstein fruit tree, all stitched together.'"

Paul is also introduced to the Golden Dawn tangerine that Luis has developed. It is a seedless tangerine that is very juicy and resistant to cold snaps, making it very valuable to the part of Florida in which they are living. The Golden Dawn tangerine is the subject of Paul, Tino, Teresa and Henry D.'s science project.