Method for treating pineapples

DETAILED DESCRIPTION OF THE INVENTION This invention is based on the surprising discovery that certain plant growth regulators are effective for extending the shelf life of fresh pineapples.
Accomplishment of this desirable goal is realized by treating the crowns of the pineapples with sufficient amounts of the plant growth regulators to retard withering and senescence of the crowns.
The plant growth regulators found to be effective for the purposes of this invention are the gibberellins, a group of naturally occurring and structurally related organic compounds having in common the gibbane skeleton: ##STR1## The most widely used gibberellin at the present time is gibberellic acid which is frequently referred to in the literature as GA.
sub.
3 whose chemical nomenclature is 2,4a,7-trihydroxy-1-methyl-8-methylene-gibb-3-ene-1,10-dicarboxylic acid-1,4a-lactone.
At least 57 gibberellins have been identified and assigned code designations GA.
sub.
1 through GA.
sub.
57.
The gibberellins are discussed in the McGraw-Hill Encyclopedia of Science and Technology, Volume 6, pages 255-259, published in 1982 by McGraw-Hill Book Company, New York, N.
Y.
, and the teachings set forth in that article are incorporated herein by reference.
Although gibberellic acid (i.
e.
, GA.
sub.
3) is not regarded as the most active gibberellin, it is the most widely used gibberellin because it is available in commercial quantities under various trade names.
Treatment of the pineapple crowns with the gibberellins is preferably carried out by employing an aqueous solution of one or more gibberellins.
The concentration of the gibberellin(s) in the aqueous medium should be between 5 and 2,000 parts per million (ppm) and preferably between 50 and 500 ppm.
The aqueous solution may be applied to the pineapple crowns by any convenient method such as spraying, dipping or drenching so long as a major portion of the crown is contacted with the solution.
A typical treatment by dipping involves submerging the crown for 10 seconds in a solution containing 200 ppm gibberellins followed by a 5-second draining period