Some of these gases can cause changes in color, texture and flavor in the crops producing them or in crops stored nearby. Ethylene is one of those gases. It is a colorless, odorless and tasteless gas produced in significant quantities by apples, pears, peaches, plums, apricots, cantaloupes and tomatoes. This gas can cause premature ripening of the fruit and is used commercially to ripen green tomatoes. It can also cause some loss of green color in leafy vegetables, peppers, cucumbers and squash.
Ethylene can cause the formation of a bitter compound in carrots and possibly parsnips.
Very often only one storage area is available and the home gardener may want to store small volumes of some crops with larger volumes of others. The storage conditions should then be made suitable for the larger crop. If only a very small amount of one kind of produce is to be stored, it may not influence the larger volume of other crops. Celery has also been known to impart off-flavors to other materials. Onions are seldom stored with other crops because of odor transfer.