Wilding Conifer Spraying on Fernhill Loop.
The Department of Conservation has contacted us to advise that they will be spraying the wilding pines in the Ben Lomond/Fernhill loop area from 10 December to 10 February. There will be closures to certain areas/mountain bike trails throughout this time so please respect all signs for your own safety. For full details please read below.
2015-2016 Operation Spray Plan Aerial boom spraying of herbicide for the control of wilding conifer trees at: Ben Lomond, Queenstown Prepared on 16th November by Robert Schadewinkel Operations Manager, Wilding Conifer Group (WCG) 027 807 7988,
Department Of Conservation Overview Wilding conifers have been spreading uncontrolled for many years across in this area and into other catchments that are highly sensitive to the impact of these trees. Wilding conifer control by ground crews has been carried out on Ben Lomond above Fernhill for many years. The new seedlings and infestations are now uncontrollable using manual methods and the spread is moving up onto the ridge top with seed is being blown over onto Five Mile and Ben Lomond Station. The plan this year is extend further east of previous years spraying sites covering an area of wilding forest totalling 28 hectares.
The location is a circular knob of forest between One and Two Mile Creeks at an altitude of between 650-900 metres above sea level.The main species present is Douglas-fir (Pseudotsuga menziesii). The method of control is aerial boom spraying via a helicopter. Sensitive areas include dwellings that are approximately 600 metres from the closest edge of the spray area and the Fernhill to One Mile Track passes through the operational area. The track climbs up a leading ridge from Fernhill up to Pt 937 then traverses around to One Mile Creek, this track passes through the middle of the aerial boom spray block. There are no roads near the spray area. There are no known water intakes from One & Two Mile Creeks.
Chemical used: To target the Douglas-fir the herbicide ‘Answer’ (Metsulfuron) is used. This chemical is readily used in farming to control gorse. This is a selective herbicide that does not affect grasses/tussocks. ‘Answer’ has an acute dosage measurement of greater than 5000mg/kg for acute oral ingestion. In layman’s terms an average adult of 60kg would have to eat 300 grams of the concentrate to experience serious adverse effects. This is a very low toxicity herbicide. Added to the above herbicides are two adjuvants, ‘Kondemn’ and ’Input’ to enhance the uptake of the spray. Canola oil is also added to aid penetration into the plant and reduce spray drift. It will take up to two years for all the sprayed trees to die. It’s not known how long they will stay standing dead as it varies, depending on annual rainfall, relative humidity, aspect of the slope the tree is on – they all contribute to the dead tree’s breakdown. Trees tend to ‘melt’ rather than fall over. The limbs come off first, then the top section, and so on.
2 Strategies employed to avoid contamination of sensitive areas: Spray operations will be undertaken in such a way as to minimise impacts on waterways. No water taken from ground water for domestic use has been identified in the spray area
No chemical will be directly applied to any waterways. High volume of crop oil will be added to the spray mix to help stop any spray drift (i.e. 20L/Ha, standard rate 2L/Ha)
Due to the presence of trees between the spray area and any dwellings this further reduces the risk as they act as a barrier
A 500 metre buffer is provided to any dwelling
All agrichemicals used have low vapour pressure, as such the risk of volatilization is low Large orifice nozzles that generate droplets over 600 micron specifically designed to reduce spray drift will be used.
Specific climatic and operational conditions listed below will be met
Operational briefings will take place prior to flying and spill kit equipment will be held on-site A Copy of this plan has been supplied to Otago Regional Council.
A Copy of this plan has been supplied to Public Health South
Timeframe and Specifications: This operation will take place between 10th December 2015 and 10 February 2016 (excluding 25 December to the 5th of January). Specific climatic and operational conditions will need to be met on the day such as; wind speed less than 10km/hr wind direction, steady and blowing up slope away from the road and any dwellings ? no heavy rain forecast for the 36 hrs following the operation Humidity >40% (Kondemn is being added to the mix to help combat the effects of low rate of humidity) Temperature not greater than 25deg C and not less than 2 deg C High rate of crop oil added to reduce possibility of drift. Approx 20 l/ha Staff on site at several points around the spray zone measuring/ recording climatic conditions every 30 minutes Wind direction monitoring tape to be placed in critical positions visible to the pilot.
All parties to be in communication with the operations manager at all times during the operation. Buffer zone of at least 500m between spray zone and any dwelling. NZS1409:2004 Appendix M Agrichemical use will be followed. Signs to be placed at prominent access points to the area being sprayed. Staff will monitor on-site during spray operations Material Safety Data sheets on all products used are available on request