Agronomy Advice

Foliar nutrition increases potato tuber bulking

By: Jez Wardman

Potato tuber bulking can be maximised by optimising crop nutrition to maintain tuber growth rates throughout the important bulking stage.

Foliar nutrition increases potato tuber bulking
Foliar nutrition increases potato tuber bulking

Maintaining a green leaf canopy longer helps increase the tuber size by allowing photosynthesis to continue efficiently so increasing yield. The potato is inherently inefficient at utilising soil nutrients, therefore additional nutrition in the foliar form is an ideal way of getting nutrition into the leaf. 

YaraVita Magphos K applied during bulking increases tuber size

Potatoes are highly responsive to foliar phosphorus, marketable yield and tuber size can be improved. During bulking, roots lose their efficiency and phosphorus from shoots is translocated to tubers so foliar phosphorus maintains leaf phosphorus status extending the bulking period.

To maintain tuber growth during the tuber bulking stage foliar phosphate should be applied where soil supplies aren’t sufficient. Recent trials work carried out by ADAS confirms that foliar phosphate, when applied after tuber initiation, has a positive effect on tuber yields by increasing the tuber size.

Magnesium is an important nutrient at the bulking stage as low levels of magnesium will reduce the starch content of tubers and protein levels that affect the taste of the potatoes once cooked. Dry soils can restrict magnesium uptake; therefore a foliar spray can be very effective. 

YaraVita Magphos K can be applied to increase the tuber size during bulking at a rate of 5 l/ha with upto 2 applications. 

YaraVita Croplift Pro helps maintain an efficient green leaf canopy for longer

A high nitrogen multi-nutrient foliar fertiliser is essential during this stage as it helps maintain green leaf canopy. With the remainder of main nitrogen dressings having been applied at tuber initiation, additional requirements can be applied during bulking through several foliar sprays with applications of YaraVita Croplif Pro.

YaraVita Croplift Pro can be applied at a rate of 2.5 to 5.0 kg/ha. Repeat at 10 to 14 day intervals as necessary.

Widely tank-mixable with blight sprays

YaraVita Magphos K and YaraVita Croplift Pro are widely tank-mixable with blight sprays so there is no need for a separate application. Further details of tank-mixabilty can be found via TankmixIT  app or at

Potato agronomy and fertiliser advice
Potato agronomy and fertiliser advice

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