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.
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.
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 have a beneficial effect on growth being the regulators of water in and out of the plant and nutrient movement around the plant.
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 is an important component of chlorophyll and is therefore vital for maximum photosynthetic activity which drives yield development.
During this 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.
Temperature, intensity of light and water supply have a great impact on both the yield of roots and their sugar content, unfortunately growers have no control over these except for a few with irrigation.
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.