How to reduce the incidence of potato soft rots

Potato soft rots are a range of warm weather bacterial diseases that enter the tubers through mechanical damage and rot the tubers in storage.

Correct balanced nutrition of the crop prior to harvest, particularly calcium and boron nutrition can have positive effects against soft rots.

Calcium reduces the severity of infections

Evidence show that strengthening the tuber cell wall with calcium can help reduce the severity of Erwinia soft rot in storage.

This study shows the relationship between calcium availability, peel calcium content and weight loss caused by Erwinia soft rot.

High levels of calcium in the tuber also reduce bruising risks at harvest and subsequent transportation. Varieties vary in their calcium uptake, however, using calcium nitrate rather than ammonium nitrate maximizes uptake, reduces the risk of damage allowing ingress of disease.

This trial from the USA shows that the use of calcium nitrate rather than ammonium nitrate resulted in higher levels of calcium in tubers over a range of different varieties.

Boron improves tuber storage quality

Alongside potassium, calcium and magnesium, boron is an important element present in the cell wall. Here it acts as cement between pectins, providing cohesive strength for cell tissues. Therefore boron affects tuber storage quality characteristics. Boron also affects calcium absorption, so supplies are important to ensure a balanced nutrition.

This trial shows how boron influences the calcium content of tubers and so also the incidence of internal rust spot.

Other crop management practices reducing potato soft rots

Harvesting early, thereby minimising late disease ingress or tuber deterioration
Taking care during harvest and grading to reduce physical damage and bruising
Disinfecting seed storage areas to reduce disease carry over
Harvesting in good conditions to avoid physical damage and disease infestation.
Using in-store treatments (e.g. fungicides) to reduce tuber disease build-up
Controlling tem peratures and humidity in storage

Recommended Yara fertilisers for potatoes

YaraMila ACTYVA S

15.6-14.6-14.6+ 6.5 SO3 - Granular fertiliser often used for grassland, winter cereals and oilseed rape to supply phosphate and potash together with nitrogen and sulphur.

YaraLiva TROPICOTE

15.5% N + 26.3% CaO - Granular calcium nitrate fertiliser for field application to a wide range of crops.

YaraMila MAINCROP

14-13.6-20.6 - Compound granular fertiliser ideal for potato crops where sulphur is not required.

YaraMila COMPLEX

12-11-18 + 20% SO3 - Prilled NPK fertiliser which also contains magnesium and sulphur as well as micronutrients ideal for use on a wide range of arable and horticultural crops.

YaraVita MANTRAC PRO

A flowable liquid micronutrient fertiliser containing 500 g/l of manganese for application as a foliar spray or seed treatment to a wide range of crops.

YaraVita MAGPHOS K

A liquid fertiliser containing a high concentration of phosphate together with potash and magnesium for foliar application to potatoes and other crops.

YaraVita MAGFLO 300

A flowable liquid fertiliser containing 300 g/l magnesium for foliar application to cereals and potatoes or treat magnesium deficiency in a wide range of crops.

YaraVita CROPLIFT PRO

A foliar fertiliser containing multiple nutrients and micronutrients for foliar application to a wide range of crops during times of stress or periods of rapid growth.

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How to maintain potato health with nutrition

A well balanced crop nutrition programme will ensure that plants are robust and resilient, whilst avoiding excessive nutrient build up that can also be detrimental to plant health

How to reduce incidence of potato foliar diseases

Nitrogen applications can have the effect of encouraging foliar diseases, particularly applications later in the season which delay maturity and increase the risk of blight infection.

See all potato nutrition articles

Potato agronomy advice

Establishing potatoes successfully

As with any other crop, good nutrition is key to securing a healthy potato crop, one that will return good yield and high quality and ultimately achieve a better profit margin for you.

Is your potato quality being let down by a lack of calcium?

Calcium is a vital nutrient for potatoes and most aspects of tuber quality can be improved by having a sufficient supply of calcium during growth.

Agronomy Advice - Increase potato yield with better phosphate management

Increase potato yields with better phosphate management

Ensuring sufficient phosphate is available for early development is critical in potatoes so perhaps it is time for a re-think about phosphate management.

See all agronomy advice

How to make better informed nutrient decisions

Our collection of tools help you to make better nutrient decisions in making the right fertiliser choice and applying the right amount of nutrients at the right time and in the right place so that the crop yield and quality can be maximised whilst still keeping costs in check, avoiding over-fertilisation and protecting the environment.