I've been pondering what JA was telling us in that dialog in chapter 6 between Dr. Grant and Mrs. Norris about the apricot tree. Why did JA write this particular dialog?
Superficially, it's another instance where we see Dr. Grant focused on the goodness of his food, and Mrs. Norris sponging off Sir Thomas and focused on the price of everything. (It's interesting how JA always portrays having an interest in good food as sinful -- as if virtuous people must be indifferent to what they eat.)
But what are we to make of that apricot tree? I believe both Dr. Grant and Mrs. Norris are telling the truth: the tree really does bear poor quality apricots, despite good soil, yet it was bought as an expensive tree intended to produce superior fruit. It seems that Sir Thomas has the means and intention to produce good fruit, but somehow the fruit ends up bad. A foreshadowing of his childrearing efforts? Is there anything else here?