Nutrient deficiencies and foliar sampling

Trees can develop certain nutrient deficiencies for numerous reasons and this can lead to slow growth rates which will reduce the potential timber yields.

Detecting the symptoms of nutrient deficiencies early is very important. Signs to watch out for are: yellow/shorter needles and slower growth. Especially the presence of heather may indicate a need for some fertiliser.

A foliage analysis is the best way to determine exactly what suspected nutrients are missing and a recommended remedy will be advised.

The appropriate time to take samples is December for conifers and August for broadleaves and larch. 

Here are guidelines how to collect needles for foliar analysis:

1. Collect needles in December (approximately 10 cm long) from branches from the top half of the tree (never collect main shoot)
2. Collect 1 branch per tree from 25-30 different trees: do not mix different species (do not mix Norway spruce with Sitka spruce for instance) and take samples from trees with the same symptoms (e.g.: all branch tips are yellowish)
3. Put all 25-30 branches in a clean freezer bag punctured with numerous small holes for aeration
4. Clearly label the bag with date, location and surname and keep the samples cool (at bottom of fridge) and make a note for yourself where that sample was taken
5. Fill in a foliar sampling form available from your local Teagasc forestry development officer
6. Pack bags with completely filled-in form and cheque in a strong envelope
7. Send off immediately to a laboratory (avoid holidays / weekends).

The following laboratories are in a position to carry out foliar sampling:

• Southern Scientific Services Ltd, Dunrine, Killarney, Co Kerry, 064 6633922
• François Bochereau - Laboratory manager, Forest Research Centre, Alice Holt Lodge, Farnham, Surrey, GU10 4LH, UK, + 44 1420 22255 Ext: 2273