A series of independent human-induced, non-transgenic mutations found in at least one non-ripening (NOR) gene of tomato tomato plants having these mutations in at least one of their NOR genes and a method of creating and identifying similar and/or additional mutations in the NOR gene by screening pooled and/or individual tomato plants. The tomato plants of the present invention exhibit fruit that ripen more slowly, rot more slowly, are firmer, and have a longer shelf life post-harvest as a result of non-transgenic mutations in at least one of their NOR genes.