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The ABCs of spraying

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An annual aerial spray program using biological pesticide makes for a complex project owing not only to the number of phases to be carried out according to a specific sequence but also to the involvement of all of SOPFIM’s units, the central and regional authorities of the provincial Ministry of Natural Resources, and the various stakeholders in forest protection efforts.

This type of intervention remains subject to the most stringent legal and regulatory framework in North America, not to mention the many moods of Mother Nature, all of which can make the logistics of spraying under a tight budget quite complicated indeed. In addition, the treatments centre on the use of a living organism on infested forests, which entails having a thorough (though imperfect) understanding of the relations between meteorological conditions, the insect pest, its food source, and Btk.

Planning an aerial insecticide spray program

During periods of epidemic, the annual planning of a protection program begins with a fall inventory of dormant insects. Working from the recent history of defoliation, this assessment of anticipated infestation levels constitutes the basic information for prescribing treatments in areas qualifying for direct protection. At the request of the Quebec minister responsible for forests, the intervention plan developed by SOPFIM is submitted for analysis by the central and regional authorities of the Quebec Ministry of Natural Resources.

Then, the forested areas targeted for protection are divided up into spray blocks, which differ from one another in terms of the number of prescribed applications of insecticide. Any area presenting a certain environmental sensitivity is surrounded by an insecticide-free strip. Spray missions are prepared using a leading-edge GPS technology in order to specifically target those forests requiring protection. SOPFIM establishes a sampling network for tracking the seasonal development of a given insect as well as the bud break of trees, all with a view to optimizing the synchronization of spraying with the feeding period of caterpillars.

Annual planning 2012

Annual planning 2011

Annual planning 2010

Annual planning 2009

The seasonal sequence of interventions

Implementation of the program is the culmination of more than 10 months of preparation and planning for a team of seasoned professionals! In consideration of a set of factors – the previously determined protection goal, the developmental stage of the targeted insect, and annual shoot growth – protection treatments using Btk are concentrated in the month of June. The entire process is kicked off with the establishment of a centre of operations, the delivery of products by tank truck and the arrival of various aircraft. Using a representative network of sample plots, the Survey unit authorizes the beginning of treatments for each forested area in relation to the development of the insect and tree foliage.

From that point on, the Operations unit takes charge of conducting all spray-related tasks. Each morning, as soon as the sun rises (around 4 a.m.), an aerial monitor takes off aboard a control plane and heads out for the targeted spray blocks. As soon as weather conditions allow (i.e., low winds and high relative humidity), he orders the loading and take-off of spray planes. Spray planes are single-engine aircraft that are regularly used in the agricultural sector. Each plane is equipped with a GPS that has been fitted out with several applications to enhance the pilot’s safety. Several actions are automated, including, on the one hand, the start and end of spraying in relation to the boundaries of the spray blocks and the exclusion zone, and on the other hand, adjustments to the flow rate according to variations in speed, the position on the flight line, etc. These different technologies also serve to optimize the deposit of insecticide on foliage in the blocks targeted for treatment. The aerial monitor supervises the work performed by the pilots, records all the data pertaining to the spraying session, and provides support to pilots in the event of any problem. Usually, planes return to the centre of operations around 6:30 a.m. Checks are then performed on the equipment, and every spray path recorded by the GPS of planes is viewed on computer.

Depending on the weather, a second spray session can be run in the evening, between 6:30 p.m. and 8:30 p.m. The same procedure as described previously is followed. Usually, five days after the first application, a second application of the product is required in order to control high populations in a given block. Depending on the weather, a protection program usually runs for a month.

Environmental monitoring

Although SOPFIM plans its operations quite rigorously, a program of environmental monitoring is implemented from the very start of operations. This program, in accordance with SOPFIM’S environmental policy, is designed to ensure the compliance of operations with existing regulations, the environmental management system, as well as SOPFIM’s internal rules and procedures. As part of carrying out this program, all centres of operations and all field laboratories are inspected. Inspections are also performed at different times throughout the operations themselves. Since it is often quite difficult to disassociate health and safety from environmental considerations, the monitoring program is also designed to ensure the safety and welfare of SOPFIM’s employees. SOPFIM takes all necessary measures to reduce the risks associated with each job to a minimum.

Environmental follow-up

Since its founding in 1990, SOPFIM has carried out a program of environmental follow-up concerning its Btk spraying operations. This follow-up makes it possible to gain a good understanding of the behaviour of Btk in the environment for the purpose of measuring its impact. SOPFIM makes a point of setting up a network of water and soil sampling stations prior to the start of a protection program. This network of stations is laid out in relation to the location of spray blocks, environmentally sensitive areas, watersheds and the representativeness of types of habitat. At some time in May, each sampling station is visited and samples are collected. Following aerial spraying operations, the stations are visited again and a new series of samples is taken. Three months later, this procedure is performed one last time. The collected samples are then analyzed at SOPFIM’s microbiology laboratory for the purpose of assaying the concentration of Btk. This procedure thus serves to track the progression of the insecticide in the environment and the resulting data can be used to keep the public informed.

Environmental monitoring report for_2014

Environmental monitoring report for_2013

Environmental monitoring report for_2012

Environmental monitoring report for_2011

Environmental monitoring report for 2010

Environmental monitoring report for 2009

Aerial spray program efficacy

The ultimate goal of Btk spray programs is to keep the forest alive during an epidemic. Accordingly, the annual protection target established by government authorities is to preserve at least 50% of the new foliage produced by trees under attack. The Quebec Ministry of Natural Resources considers a program to be a success when this target has been achieved on at least 70% of the forest areas treated.

The ministry conducts an initial assessment by air. SOPFIM performs field inventories that can be used to assess mortality levels among the targeted insect population as well as the level of protection afforded to annual foliage; this process is based on comparisons between treated and untreated (control) zones.