Timing of harvest

Table potatoes
Table potatoes are in general left in the field until maturity.
An early harvest of the crop (before maturity of the crop) gives as a result a relatively low yield of the crop, relatively small tubers, a relatively low dry matter content of tubers and a high content of reducing sugars.
Waxy potatoes
These are the early harvested new season potatoes. They have a waxy texture that prevent them absorbing water and breaking up, as such they are great for boiling.

Seed potatoes
In seed production an early harvest is common practice . This to reduce the risk of infections with especially virus diseases and to harvest a high percentage of seed sized tubers.
The early harvest results in a relatively low total tuber yield. This low yield is a main reason for the high production cost of seed.

Maturity and timing of harvest
The time of harvest, in relation to the maturity of the crop, influences: Harvest time, yield and tuber size, crop cycle and maturity
Harvest time influences tuber size and yield. Harvest of immature crops leads to relatively low yield and small tubers.
HARVEST TIME: MATURITY- YIELD - SIZE

Maturity, harvest time and internal quality
During the growing season the chemical composition gradually changes. At the beginning of the growing season the dry matter content is low and the sugar content is high. Tubers when harvested immature have a low dry matter content and a high sugar content. Reaching maturity dry matter increases and sugar content drops.
Crop management measurements leading to more uniformaty in tuber initation results in a crop yield with better processing characteristics (size, dry matter, sugar content).
Changes in dry matter and sugar content

Maturity, harvest time and skin quality
Immature tubers have a weak skin and a relatively long period is needed between haulm destruction and harvest when crops are harvested mechanically. Tubers without a sufficiently well-developed skin are easily damaged and will lose much moisture during storage, furthermore, micro-organisms can easily enter such tubers. When a tuber is injured or deliberately cut, the formation of a new cork layer is needed to protect the tuber against infection as well as against excessive loss of moisture.
SKIN