Science Into Practice - Nitrogen levels for blueberries

Larger blueberry bushes have significantly greater potential yields. Accurate nitrogen application is important to encourage growth. However, clear recommendations on the level of nitrogen required are not currently available.

An AHDB-funded project investigated nitrogen application for pot-grown blueberries to ascertain optimum application timing for maximising yields while reducing the risk of frost or cold injury to bushes and flowers.

The varieties Duke and Aurora were included in the investigations. In the first year of the project, three different levels of nitrogen feed (60mg/l, 120mg/l or 180mg/l) were applied throughout the season from March until October. In the final three years, the use of high-nitrogen (180mg/l) and low-nitrogen feeding (60mg/l) applied in the autumn, spring or summer growth periods was compared. During the periods when high/low feeding was not applied, an intermediate level of 120mg/l was used.

Little effect was seen from varying nitrogen levels throughout the season or for periods within the season. There were no adverse effects on plant growth or yield at the highest nitrogen concentration of 180mg/l and it would appear that levels of 60mg/l would be adequate for blueberries because nitrogen is not a limiting factor at this low regime. However, there were indications that there was also some consistency in maintenance of improved Brix, percentage of marketable fruit out of store and class-one yields over the seasons for the following regimes:

- Aurora: autumn low/spring high.

- Duke: autumn low.

Results show that, in general, lower levels of nitrogen are sufficient for pot-grown blueberries that could give rise to cost savings across the season.

The full report for project SF137 is available online at

For details on all AHDB Horticulture activity, see

Have you registered with us yet?

Register now to enjoy more articles and free email bulletins

Sign up now
Already registered?
Sign in

Read These Next

Has vertical farming passed a peak on the 'hype cycle'?

Has vertical farming passed a peak on the 'hype cycle'?

Several senior industry figures sounded a note of caution on the potential of urban farms at last week's GreenTech international trade show in Amsterdam (12-14 June).

How can growers benefit by supporting agroforestry?

How can growers benefit by supporting agroforestry?

Agroforestry has the potential to deliver on a range of policy objectives in England, according to a new report from the Woodland Trust and the Soil Association.

How should perceived shortcomings in Defra's farming policy plans be addressed?

How should perceived shortcomings in Defra's farming policy plans be addressed?

The Government needs to provide much more detail on its post-Brexit farming policy if its twin aims of increasing farm competitiveness and enhancing the environment are to be met, according to a new report published this week by the parliamentary Environment, Food & Rural Affairs Committee.

Follow us on:
  • Facebook
  • LinkedIn
  • Twitter
  • Google +

Horticulture Week Top UK FRUIT PRODUCERS

See our exclusive ranking of fruit producers by annual turnover. 

Horticulture Jobs
More Horticulture Jobs

Pest & Disease Tracker bulletin 

The latest pest and disease alerts, how to treat them, plus EAMU updates, sent direct to your inbox.

Sign up here

Professor Geoffrey Dixon

GreenGene International chair Geoff Dixon on the business of fresh produce production

Read Professor Geoffrey Dixon