Temperature Temperature is the most important environmental factor that influences the deterioration of harvested commodities. Most perishable horticultural commodities last longest at temperatures near 0ºC. At temperatures above the optimum, the rate of deterioration increases 2- to 3-fold for every 10ºC rise in the temperature. Temperature influences how other internal and external factors influence the commodity, and has a dramatic effect on the spore germination and growth rate of pathogens. Temperatures outside the optimal range can cause rapid deterioration due to the following disorders: