Forestry Commission Scotland has postponed its aerial application trial of a fungicide until 2015 – mainly because of the weather!
The intended application of fungicide by helicopter was to be the second of three such trials to help determine if the technique could practicably be used as a last-resort option to help limit the damaging impact of the pine disease, Dothistroma needle blight.
The fungal pathogen responsible for the disease attacks pine needles, which in turn limits the rate of tree growth, potentially leading to their death as well as reducing the timber yield and value. The potential future impact of Dothistroma on our iconic Caledonian pinewoods adds further weight to the need to examine potential options for the management of this serious disease of pine.
Hugh Clayden, the Commission’s tree health policy adviser, said:
“Protecting Scotland’s forests and limiting the damage from tree pests and diseases is a continuing challenge and we need to consider all options when looking at the most effective way of managing these threats.
“Following last year’s small but successful trial near Elgin we’d hoped to be able to treat a small area within Millbuie forest on the Black Isle this year, but over the period when we could have flown it was often either too wet or, odd though it may sound, not windy enough for the effective use of the application system .
“Additionally, on the few occasions when a suitable weather window opened up we were either unable at such short notice to provide the necessary ground crew for the stringent pre- and post-spraying monitoring work, or a helicopter with a pilot licensed to undertake this skilled work was simply not available.
“It’s been very frustrating for all concerned, but we were simply not prepared to undertake the trial unless weather conditions were suitable and we had sufficient skilled personnel available to support the work. However, we are determined to complete these trials to establish whether or not the technique is safe, sustainable and effective for targeted use in Scottish forests.
“We are very grateful indeed for the level of understanding and co-operation we have received from a wide range of interests, including the bee-keeping community. “
The Commission has a three-year permission from the Chemical Regulations Directorate to conduct these aerial application trials.
The ultra low volume aerial application technique requires wind speeds of 10-25 knots to provide sufficient canopy turbulence to ensure the microscopic droplets dispersed by the spraying system are retained in the upper tree canopy. Results from last year’s trial at Monaughty confirmed that over 95% was captured in the tree canopy (where we want it) rather than falling to the ground straight away.
The season for the potential use of fungicide to help manage Dothistroma needle blight is now over, but work has already started to plan next year’s trial.