On Tue, 17 Aug 2004 05:19:57 GMT, Fred wrote:

Some people say an apple works, some say a banana does the same thing. But
do you use a green apple, ripe apple, started-to-become-rotten apple, yellow
banana, black banana? Huh? Let's have some facts here, ma'am... just the
facts!

No facts, but some questions instead. If ethylene gas works, what
is the minimum concentration needed to ripen effectively (if
avocados are among the fruits that it is effective with), would one
apple suffice or would many be needed? How permeable to ethylene is
a paper bag? Would a plastic bag or container retain the gas longer
at a higher concentration? I doubt that light/dark cycles would
matter but temperature might. Be prepared to run dozens of
experiments and have lots of chips and a good guacamole recipe

Some time ago - it might be 20 years or more - I read about the
effectiveness of ethylene on tomato ripening. As they were shipped
to markets in railroad boxcars, ethylene gas was introduced.
According to the article the primary effect was to redden the
immature fruit, without actually ripening anything. The packers got
what they wanted. Red, firm fruit still hard enough to resist the
bruising that accompanies handling and shipping, but lacking the
better taste produced by natural ripening. The article might have
been one of John McPhee's written for the New Yorker on
greengrocers. For a moment I thought that I could provide you with
a ready source of ethylene, but I was mistaken. When you add water
to calcium carbide it produces acetylene instead. Not very useful
unless you want to shoot the fruit from a cannon.