Tuber physiology
Tubers are used for consumption and for reproduction. Physiological processes and production methods affect tuber quality with regard to:
1.) tuber size, 2.) dormancy, 3.) respiration losses, 4.) transpiration losses and 5.) changes in chemical composition.
These processes take place during both the production season and the storage season.
Tuber size
For the use as seed relatively small tubers are used, while for the production of french fries large tubers are desired.
Crop density and length of the production season (yield) influences tuber size.
SIZE, YIELD AND PRODUCTION SEASON====CROP DENSITY AND SEED RATE
Dormancy and sprout growth
Potatoes are dormant and do not produce sprouts for a considerable period of time after maturity and harvest.
DORMANCY-SPROUT GROWTH
Respiration
In respiration, oxygen is absorbed from the air and together with carbohydrate (sugar) from the tuber, converted into carbon dioxide and water.
RESPIRATION
Water losses
During storage of potatoes water evaporates through the skin, wounds and sprouts. Water losses can be reduced by avoiding skin damage delaying sprout growth and applying adequate storage methods.
DRYING OF TUBERS AND WATER LOSSES
Chemical composition
The chemical composition of the potato is determined by the variety, growing conditions (duration), storage duration and storage temperature.
With adequate storage management tubers can be kept at or be changed to desired quality.
CHEMICAL COMPOSITION