Science Into Practice - Tackling tipburn and leaf spot

Cordyline yellow leaf spot syndrome and tipburn are major problems in cordyline and phormium crops. Production is commonly affected, but until AHDB Horticulture-funded project HNS 171a, growers had been unable to take preventive action because there had been no clearly defined cause.

With two-million or more cordylines and phormiums grown each year, downgrading and annual losses from these disorders are estimated at more than £1m.

Building on findings of a previous project - in which viral infection, nutrient imbalance, high fluoride and environmental stress were investigated as possible causes - this project aimed to identify practical measures to minimise the incidence of both conditions.

Leaf tissue analysis indicated less potassium and calcium were present in plants with symptoms. Calcium nitrate as a foliar feed and potassium nitrate as a liquid feed were shown to reduce the incidence of both tipburn and yellow leaf spot in cordyline when used at the correct dose.

The best commercial option was suggested to be an application of calcium nitrate (liquid feed, 75mg/litre calcium) plus potassium nitrate (liquid feed, 75mg/litre potassium). This resulted in the best-quality plants, even though leaf spot reduction was not statistically significant.

As a result of the project, a number of growers have started to use calcium as a foliar feed for cordylines and are seeing less severe tipburn and yellow leaf spot syndrome, although symptoms have not been completely eliminated.

The full grower summary for HNS 171a can be accessed online at

AHDB Horticulture

For details on all AHDB Horticulture activity, see

Before commenting please read our rules for commenting on articles.

If you see a comment you find offensive, you can flag it as inappropriate. In the top right-hand corner of an individual comment, you will see 'flag as inappropriate'. Clicking this prompts us to review the comment. For further information see our rules for commenting on articles.

comments powered by Disqus

Read These Next

Pest & Disease Factsheet - Green manure crops

Pest & Disease Factsheet - Green manure crops

Valuable tools to combat pests and diseases, improve soils and boost nutrient levels.

Pest & disease Factsheet - Whiteflies

Pest & disease Factsheet - Whiteflies

Whiteflies are sap-sucking insects that can be found in high numbers on protected crops such as tomatoes, cucumbers, peppers, chrysanthemum, fuchsia, abutilon and gerbera. They can also attack outdoor crops including brassicas.

Pest & disease Factsheet - Powdery mildew

Pest & disease Factsheet - Powdery mildew

Accurate identification is key to tackling this serious plant disease.