Produce preservation

Two of the most important factors in improving storage life of fresh fruits and vegetables are the temperature and humidity of their storage conditions. Most fresh fruit and veggies require temperatures between 32-55°F and relative humidities of 80-95% but this varies widely by crop type, crop maturity at harvest, the climate where the crop originates from, plant part, and more. A general rule for vegetables is that crops harvested in the cool season should be kept at cooler temperatures (32-35°F) while crops harvested in the warm season should be kept at warmer temperatures (45-55°F). However, there are many exception to this.

Temperatures that are too low can cause freezing injury in some crops while others can be repeatedly frozen and thawed. Common signs of injuries are loss of rigidity, water soaking, and softening. Many warm-season crops are also prone to chilling injuries which happen when produce is stored at near freezing temperatures.

An optimal storage set up would include 3 storage facilities: cold storage (32-36°F), cool storage (40-55°F), and a warmer storage (55-60°F) for sweet potatoes, squash, and similar crops.

Further readings
See also:
 * The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks
 * UC Davis - Produce Fact Sheets

References: