Processing high dry matter content is required to achieve a good fry colour and often 20-25% is specified. Nitrogen, potassium and magnesium can all have an influence on tuber dry matter content.
– Low levels of magnesium will reduce the starch content of tubers and trials have confirmed the positive benefits of magnesium on tuber dry matter and specific gravity.
– Nitrogen is an essential nutrient to fuel canopy growth.
– Late harvesting can cause cracks with many ‘oversize’ potatoes
Other factors include:
1. Selecting the right variety to meet dry matter production needs (Fianna, Markies, Moonlight)
2. Planting certified seed such that there is a much lower risk of diseases.
3. Avoiding fields with adverse factors such as poor drainage or low water-holding capacity.
4. Ensuring spray programs are effective .e.g. against early and late blight.
5. Scheduling irrigation to maximise quality characteristics printing stunned growth (under-watering) or growth cracks (inconsistent watering).
6. Harvesting early, thereby minimising late disease attack or tuber deterioration