Farm Forestry New Zealand
PESTS AND DISEASES OF FORESTRY IN NEW ZEALAND
Upper mid-crown yellowing (UMCY) in young radiata pine trees
Scion is the leading provider of forest-related knowledge in New Zealand
Formerly known as the Forest Research Institute, Scion has been a leader in research relating to forest health for over 50 years. The Rotorua-based Crown Research Institute continues to provide science that will protect all forests from damage caused by insect pests, pathogens and weeds. The information presented below arises from these research activities.
From Forest Health News 83, March 1999.
In late spring of 1998 five- to six-year-old Pinus radiata in some stands in the central North Island exhibited a marked chlorosis, decreased needle length and needle loss in the mid-upper part of the crown. This is a fairly typical upper mid-crown yellowing (UMCY) symptom but unusual in the youth of the affected trees. As a general rule needle-tip chlorosis is the indicator of Mg deficiency in trees under ten years old while UMCY is more usually found in trees over the age of ten. Soil nutritionist Peter Beets (Forest Research) has found these symptoms on some farm forest sites with high K/Mg ratios in the foliage and believes it to be the result of an induced magnesium deficiency. Dehydration in the upper crown follows and this may exacerbate the effect.
(Bob van Boven, MAF Rotorua)
This information is intended for general interest only. It is not intended to be a substitute for specific specialist advice on any matter and should not be relied on for that purpose. Scion will not be liable for any direct, indirect, incidental, special, consequential or exemplary damages, loss of profits, or any other intangible losses that result from using the information provided on this site.
(Scion is the trading name of the New Zealand Forest Research Institute Limited.)
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