How to increase sugar beet yield

The two key components of sugar beet yield are the weight of sugar beet roots and the % sugar content of them.

The combination of a high root yield and high sugar content will give the highest yield of sugar per hectare. For the sugar factory the high sugar content gives the lowest energy consumption during sugar extraction, mainly due to less evaporation of water. Growers are therefore normally paid a premium for achieving a high sugar content. Temperature, intensity of light and water supply have a great impact on both the yield of roots and their sugar content. Growers have no control over these except for a few with irrigation.

Relationship between radiation interception and sugar yield

As well as these growing conditions, yields are set by the variety chosen. Some varieties have very high yields of roots, but lower sugar %, whilst others have low root yields with high sugar levels. High yields will come from producing a full leaf canopy that intercepts 90% of incoming sunlight as quickly as possible and maintains its greenness right through the growing season. Sugar beet, if grown well and does not flower, accumulates yield (sugar) from very early in its growth cycle. A balanced crop nutrition program including all macro and micro nutrients is essential to help manage all of these components.

Nitrogen

Early canopy growth and development is fundamental which is why nitrogen is the single most important nutrient governing the yield. However it is critical that no other nutrient limits early growth rates. Nitrogen promotes growth at all stages of the plants development. Yield improvements are due to an increase in root yield and therefore the yield of sugar. Applying excessive amounts of nitrogen can be detrimental and reduce the sugar content so applying the optimum rate of nitrogen at the right growth stage is very important.

Phosphorus

Soil conditions at sowing can limit the availability of some nutrients such as phosphorus. Fresh applications of phosphorus ensures optimal early growth helping to increase yield.

Potassium and sodium

Potassium and sodium have a beneficial effect on growth being the regulators of water in and out of the plant and nutrient movement around the plant.

Sulphur

Sulphur is an essential nutrient for high yields with ‘sulphur containing’ amino acids being the building blocks of proteins and hence growth. It is linked with nitrogen with the ratio of nitrogen to sulphur in a healthy plant being about 15:1. A higher ratio than this indicates possible sulphur deficiency.

Magnesium

Magnesium is an important component of chlorophyll and is therefore vital for maximum photosynthetic activity which drives yield development.

Micronutrients

During root expansion and growth, rapid cell division occurs which demands large amounts of boron. Deficiency of boron will cause growth to stop and lead to the deterioration of the root and leaf expansion. Both yield and quality will be reduced. Manganese, copper, zinc, iron and molybdenum are all micronutrients that are essential for the growth of sugar beet. If the micronutrients are not available in sufficient amounts application will increase yield.

Recommended Yara fertilisers for sugar beet