Can the word "fruit" be used as an invariant plural as in "the fruit are" and "two fruit"? [duplicate]

Using Google Ngram Viewer and the search terms the fruit are,the fruit is,the fruits are, and then choosing the first quote, taken from a recently published book by a native speaking author, we have

  1. The Woody Plant Seed Manual - Page 473

United States. Forest Service, ‎F. T. Bonner, ‎Robert P. Karrfalt - 2008 Found inside – Page 473

The fruits are juicy , 1- to 10 - seeded berries with enlarged , persistent calyxes at the base ( LHBH 1976 ).

  1. United States Plant Patents - Page 18 United States. Patent and Trademark Office - 2008

The size of the fruit is large or similar to the size of the fruit of Mutzu. The ratio of height ..

  1. The Encyclopedia of Fruit and Nuts - 2008 edited by Jules Janick, Robert E. Paull Found inside – Page 161 Very commonly, the fruit are covered with a waxy bloom.

The inescapable conclusion is that all are correct in context.

[20200924 - Example at 3. replaced by an example to include "fruit are"]