Agriculture Reference
In-Depth Information
It is very important that peaches and nectarines are rapidly and continu-
ally cooled. To ensure freshness, keep the temperature at about 32°F (0°C)
from packing to the consumers' tables.
Plums and Prunes
The harvest maturity of plums is largely determined by changes in color at
the tips of the fruits and by the firmness of the flesh.
The level of firmness appropriate for harvest depends on the variety and
the amount of time before the fruits reach consumers. An average firmness
of 8 to 10 pounds works for most plum varieties that will be cooled quickly
after picking and before shipping. If you cannot precool the plums before
shipping, pick them earlier, when firmness is in the 13- to 15-pound range.
Fully ripe plums are very soft, measuring around 4 pounds of firmness. For
home fresh use and local fresh markets, harvest plums when they are fully
colored and still firm. Plums destined for processing can be allowed to fully
ripen on the trees.
Like peaches and nectarines, plums continue to ripen after harvest. Being
even softer than peaches and nectarines, plums intended for shipping are
picked mature but still firm and before they achieve their full color.
With the exception of loquats, plums and prunes are the most fragile
fruits covered in this topic and must be handled with great care. When pick-
ing, use a lifting and twisting motion to detach the fruits from the tree. For
fresh market and shipping plums, the stems should remain attached to the
fruit. Ripe plums in good condition can be stored for several weeks at 30 to
32°F (−1 to 0°C).
Prunes are allowed to fully ripen on the trees before harvest, usually when
they measure at about 4 pounds of firmness. The skins should be smooth
and fully colored. On a commercial scale, prunes are often machine-harves-
ted. They are dried inside ovens, or the prunes can be sun-dried.
