Growth and development of sugar beet

The first year is the vegetative phase where the establishment and the main production of the plant happens. To move into the reproductive phase (year 2) the sugar beet needs a period of vernalisation. This happens during a cold period in the winter.

Germination and establishment

Germination and establishment is very temperature and moisture dependent/sensitive. To maximize interception of solar radiation and thereby yield, sugar beet is normally sown as soon as it is possible to have a good seedbed. A uniform dense stand/canopy is the foundation for maximizing photosynthesis and requires good, even establishment. The early growth is often very slow due to low soil temperatures with only two or three leaves per week appearing. In this period the solar radiation is high but the photosynthetic unit of the sugar beet is low.

Canopy development

After the three to four weeks of establishment and when the sugar beet has 6 true leaves, the rapid canopy growth starts. Photosynthesis is used to produce the new leaves and canopy. At the point of canopy closure there are about three times more leaf area than soil surface (Leaf Area Index (LAI) = 3). Light interception reaches a maximum and the sugar beet can make use of 80-90 percent of this radiation.

Storage root growth period

After canopy closure the energy is no longer used to leaf production but to store energy in the root for the next growing season. Canopy weight remains stable for some time but later on the older leaves dies and are not replaced. The maximum daily rates of sucrose accumulation occurs in this period.

Pre-harvest stage

The growth and storage of sucrose continues but at a lower rate. Later on, the growth decreases due to lower temperatures and lower solar irradiation.

Sugar beet growth stages

The development of sugar beet can be described in more detail using a growth stage scale system. Below is the scale in detail.