Breakthrough in pine tree disease research

This pine tree on the Pahiatua Track appears to have the symptoms of red needle cast. Photo / File

Researchers at Scion have made a breakthrough in studying pine tree disease red needle cast - which falls in the same 'plant destroyer' family as kauri dieback.

The disease spreads through airborne water droplets and causes the needles to turn yellow, then red, before finally falling off.

While scientists say the disease is not as detrimental as kauri dieback, the loss of leaves slows down tree growth.

The researchers studied the way the disease behaved in both detached needles and the whole pine tree and found infection had two peaks, at four days and 22 days, which helps to shed light on disease resistance and the incubation period.

Several key drivers of red needle cast have been disentangled through the work of PhD student Mireia Gomez-Gallego, from Scion and Auckland University of Technology.

Crown forestry research institute Scion in Rotorua. Photo / Alan Gibson

Gomez-Gallego's work is important for forestry internationally as foliar diseases have emerged as significant concerns for conifer forest productivity in New Zealand, Europe, North and South America, said Nari Williams, senior forest pathologist at Scion and Gomez-Gallego's supervisor for this research.

"Mireia's PhD links studies done in the laboratory with what we are seeing in the field. Her work is a key component in better predicting the areas at greatest risk of disease, the cost to productivity and to inform forest management strategies such as the deployment of resistant genotypes," Williams said.

"This is not a trivial task. Red needle cast is one of several diseases affecting forest productivity with each having distinct environmental drivers and impacts. Managing these diseases is important for maintaining resilient forest productivity both in New Zealand and internationally.

"Our next task is to better understand how each of these combine in the forest, their combined effects and make sure that we have the appropriate forest management regime in each estate for the given disease risk," Williams said.

The work was supported by the Forest Owners Association, and the Ministry of Business Innovation and Employment.