Book 3 "Davey's New Friends" Is all about growing potatoes. Davey acquires a potato planter and then a special implement for digging them up. It hopes to show how our food is grown and has some really lovely illustrations.
The section in the back for adults is about the implements that were made for David Brown tractors. The potato planter was made by "Robot" a company owned by David Brown.
The "Davy" series of stories for young children in age range 2-7. These stories are based on true events and each story is lavishly illustrated with hand drawn art, not computer generated. Davey does exist as do all the characters and machines introduced. Each book has a small section at the back which is information for parents / adults about one of the characters in the book.