2 Methodology

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2.1 Data source

Results are based on the 2005 pilot survey on crop protection. This voluntary survey was designed to collect baseline data for the first time on quantities and types of pesticide and pest management practices used in 2005. This survey was conducted for Agriculture and Agri-Food Canada (AAFC), Environment Canada (EC) and Health Canada (HC). A total of 572 apple producers voluntarily participated in the survey conducted by Statistics Canada from January to March 2006. Growers provided information on their use of pesticides and other pest management practices during the 2005 growing season. Producers were asked to complete the survey with the help of a trained interviewer on the premises of farm operations. Surveying took place from the beginning of January to the end of March 2006. The survey questionnaire is presented in Appendix B.

The first two sections of the survey recorded information on the location, farm size, area devoted to apple production, varieties grown and orchard history. Most surveyed farms grew apples in more than one orchard and some operated a dozen or more. To reduce response burden and the time to complete the survey, one orchard was randomly selected from up to ten of the largest orchards operated by the farmer. All subsequent questions on pesticide use and pest management practices focused on this single orchard.

The survey was well received with an overall response rate of 89.9%.

2.1.1 Target population

The target population consisted of all active farms in Canada with sales of $10,000 or more reported to the 2001 Census of Agriculture, which contributed to the top 95% of the total acreage of apple. Operational constraints led to the exclusion of certain types of farms: institutional farms (prisons, research stations, colleges), farms located on Indian reserves, small farms that contributed to the lowest 5% of the total acreage of each type of crop in each region, remote farms that could not be visited by interviewers within reasonable traveling distance and cost; and farms located in the Prairie Provinces, the Yukon, the Northwest Territories and Nunavut.

2.1.2 Sample selection

The survey frame consisted of the list of all active farms from the 2001 Census of Agriculture, updated with the acreages of apple operations for the subset of farm operations that also responded to the 2003, 2004 and 2005 Fruit and Vegetable Survey. The survey frame was divided into groups, or strata, defined by region and by size of operation based on acreage (large, medium and small operations).

Farms were randomly selected within each stratum. Large farms that contributed to a significant proportion of the provincial total apple area were all included in the sample. These farms were assigned a weight of one and thus represented no other farms in the target population but themselves.

A random sample of the medium and small farms was selected. These farms were assigned a weight greater than one since they represented other farms with similar characteristics.

Furthermore, each selected orchard had a specific weight based on the probability of a farm being selected for the sample and the proportion of the selected orchard compared to the total producing area of the selected farm. Weights were adjusted after data collection for non-response and they were used to estimate results to the target population.

2.2 Survey coverage

The survey was designed to cover 95% of the total producing area in each region (Maritime Provinces, Quebec, Ontario and British Columbia). Table 1 shows how representative the results are in terms of number of operations and producing area compared with results of the 2006 Census of Agriculture and the 2005 Fruit and Vegetable Survey. Overall, the Crop Protection Survey represented 37.0% of all apple growers in Canada. In terms of producing area, the survey covered 88.1%. The growers who reported using pesticides represented 86.5% of the total producing area. The questionnaires with valid and usable information about pesticide application accounted for 81.7% of all producing area and the selected orchards represented almost half of the total producing area.

Table 1
Crop Protection Survey coverage, apple production, selected provinces, 2005

2.3 Pest management practices

A series of questions was asked about pest management practices used by apple growers on the selected orchards. Respondents were asked to identify the targeted pests, practices used to deal with the problems, expertise and information used for decision making, the basis for application decisions and whether pest pressure had changed over the last five years. Growers facing greater pest pressure were asked what they were planning to do in the next growing season to reduce the problem. Where applicable, the practices were grouped into two categories: dependent practices relying more on the use of pesticides (pesticide dependent practices) and those focusing more on prevention (integrated pest management practices).

To get a better idea of the uptake or importance of the adoption of the different practices1, each answer was expressed into the producing area covered by multiplying the area of the selected orchard by its survey weight to estimate results to the target population. One limitation of this approach is the assumption that the grower who adopted a specific practice in the selected orchard also adopted this practice to all the other orchards that the grower operated.

2.4 Pesticide use estimation

The following section describes the different statistics related to pesticide-use estimates.

2.4.1 Treated area

For each combination of selected orchard and product application (or active ingredient)2, the treated area was estimated using the total orchard area times the percentage of the orchard area treated. For each possible combination, the application used on the largest treated area was then retained as the maximum area treated over the growing season. The maximum treated area was then multiplied by the selected orchards' survey weight3. The total treated area was then calculated by summing up the weighted maximum area treated of all selected orchards for each active ingredient.

where WeightF is the survey weight of the selected orchard f; Percent_Area is the selected orchard area times the percent of the area that was treated during a single application a; Max is for the maximum value of percent area among all application (a) on the selected orchard; and f is the fth selected orchard in the survey sample.

2.4.2 Average number of applications

For each combination of selected orchard and active ingredient, the average number of applications was derived by adding the treated area of all applications over the growing season (or cumulative treated area) divided by the maximum area treated. A weighted average4 of all selected orchards surveyed was then calculated for each active ingredient.

2.4.3 Quantities of active ingredients applied

For each application, the quantity of active ingredient was calculated by multiplying the treated area by the normalized reported rate of application5. For each combination of selected orchard-active ingredient, the total quantity used was derived by adding up the quantity calculated for all applications over the growing season. These totals for each combination of selected orchard-active ingredient were then multiplied by the specific selected orchard survey weight. The quantities for each active ingredient were then calculated by adding up the quantities for all selected orchards.

2.4.4 Average rates of application

For each combination of selected orchard and active ingredient, the cumulative treated area was estimated by summing up all treated areas over the growing season. The cumulative treated area was then multiplied by the selected orchard survey weight. For each active ingredient, the average rate of application was then estimated by dividing the total quantity of active ingredient applied (as calculated in 2.4.3) by the cumulative area treated.

2.4.5 Pesticide-use intensity

For each combination of selected orchard and active ingredient, the treated area was qualified as being below, within or above the labelled rate of application (three intensity categories). The totals for each combination of selected orchard-active ingredient-intensity category were then multiplied by the selected orchard survey weight. The treated area for each active ingredient was then calculated by adding up the treated area in each intensity category for all selected orchards. For each active ingredient, pesticide-use intensity was then expressed in percentage by dividing the total treated area by the cumulative treated area for each category.

 

1. Counts of growers reporting a practice would not give a complete picture on the adoption of this practice as growers operate orchards of different sizes. For example, a practice may be significant in terms of the number of growers adopting it. However, if the majority operated small orchards, its importance may be much less significant once expressed in terms of the producing area covered by this practice.

2. Each active ingredient was considered as one application for products that contain more than one active ingredient.

3. Refer to section 2.1.2 for survey weight explanation. These weights were used to extrapolate results to the whole target population.

4. Selected orchard weights adjust average to take into account the size of different selected orchards.

5. Expressed in kilograms of active ingredient per hectare. Products in liquid form were converted into kilograms per hectare using percentage of guaranteed active ingredient and specific gravity.