Why a healthy canopy is essential for potatoes

The ideal potato crop uses very limited amounts of the sugars to maintain its canopy, thus partitioning the majority into the tubers. When considering how to minimise the energy that is required to maintain a canopy, we need to focus on how we reduce the plant’s respiration to a minimum. A plant’s respiration rate will increase when it comes under stress,which reduces the amount of sugar produced during photosynthesis that is available for tuber bulking. It is essential to manage these stresses out of the production system and for abiotic stress such as temperature or drought relief can be aided by the use of biostimulants.

Nutrient deficiencies can be monitored through plant leaf analysis. Data from Yara Analytical laboratories reveals some of the key nutrient deficiencies found in potatoes to be phosphate, potassium and magnesium. Phosphate is of particular importance due to its role in the transport of the sugars from the leaf down to the ‘bulking’ tubers. The transport mechanism is an energy demanding process and the chemical energy is stored by the plant in the phosphate based molecule ‘ATP’. Magnesium, the central component of chlorophyll (leaf greenness), clearly has an important role in keeping the leaf canopy greener for longer. Potassium helps the plant regulate water and nutrient movement from roots, through the plant, to the leaves.Water movement itself is also a necessity in the transport of sucrose down to the ‘bulking’ tubers.

By removing both biotic and abiotic stress you will ensure a healthy, well-functioning potato canopy. This will give the best chance of maximising the important ‘tuber bulking’ period, and result in high, marketable potato yields.

Recommended action: During full canopy cover, two applications of YaraVita Magphos K @ 5 l/ha + YaraAmplix Optitrac @ 3 l/ha, with 14 days between applications.