How to interpret this text from year 1847?

Solution 1:

My interpretation is that the author has selected a limited number of vegetables and fruits from a large array (the multiplicity) usually presented in other gardening books and in gardening catalogues.

These "larger works and catalogues" are not useful to farmers, gardeners or amateurs, because they present Too Much Information and offer too many varieties of seeds and cuttings.

Many of these varieties are not easily grown. Thus the farmer or market gardener cannot easily supply his market, or even easily feed his family by growing these finicky varieties. Even for the hobbyist gardener, they offer few rewards for much labor.

The above is not concise! The concise version:

In contrast to the encyclopedic approach of other books and catalogues, this book has selected a limited number of easily grown and hardy varieties of vegetables and fruits. Cultivation of these varieties will produce large yields for the farmer and market gardener, and enjoyment for the amateur.

Edit: The OP gave a link which supplies context for the paragraph quoted. It helps to read the Preface in the link, as the OP recommended.

Solution 2:

"Gardeners, farmers and amateurs have for some time needed a short list of recommended plants*; the lists in most books and catalogues are too long to be useful to those who only want to grow food either for the family or to sell at market."

.* Sort is one way of referring to the difference between a Bramley and a Golden Delicious apple. Type and variety have technical meanings: species is plainly wrong.

Solution 3:

Some selection of this kind has for some time been imperatively called for, by the wants of the gardener, farmer, and amateur, the multiplicity of sorts [large variety] in the larger works and catalogues rendering them nearly useless to those who merely wish to know those kind adapted [the ones that work] for family or market supply.

Now remove the bold text, and the meaning will magically appear.

Solution 4:

The author is simply saying:

"There's a huge amount of this information around for professionals. But plenty of people just want to know 'what the hell to buy' for family use. For that reason, I'm supplying my own, more concise version, of this information. You can sign-up now using PayPal or other (monthly repeating) payment methods."

It's That Simple.

You know how all advertising and marketing is just total, complete, unmitigated bullshit?

You've stumbled on to some marketing bullshit fro the 1800s.

Naturally it is "overwritten" in a ridiculously complicated way using too many adjective-forms, and so on.