1. State Plant Health and Seed Inspection Service
Plant Protection Institute, Sośnicowice Branch
Central Statistical Office
of Poland
PILOT PROJECT:
Transition Facility Multi-Beneficiary
Statistical Co-operation Programme 2005
Lot 2: Pesticide indicators
ESTIMATION OF NATIONAL RESULTS IN PILOT PROJECT „PESTICIDE INDICATORS” – POLAND
Authors:
Central Statistical Office of Poland – Grazyna Berent-Kowalska
– Bronislaw Lednicki
State Plant Health and Seed Inspection Service – Katarzyna Prugar
Plant Protection Institute Sosnicowice Branch – Wojciech Sliwinski
– Stanislaw Stobiecki

2. PRESENTATION OUTLINE
Review the way of performing the project in Poland
Computing the average pesticide use indicator
The results for the average pesticide use indicator for three voivodships
Presentation of methods for generalizing the results to the entire country (2 methods)
Average usage indicator – estimate for the entire country
Average usage indicator – based on projects
Examples of results following the estimation for the entire country
Survey quality
Summary
Recommendations for the national – scale monitoring

3. POPULATION FOR SURVEY STUDIES
The surveyed population includes farms from the following provinces
which have arable land areas over 1 ha and grow winter wheat
study based on wheat harvested in 2006
lubelskie
lodzkie
zachodniopomorskie
zachodnio pomorskie
lodzkie
lubelskie

4. THREE REGIONS SURVEYED
For the purpose of the studies, three regions were selected, whose plant protection practices vary due to:
Different geographic, climatic, soil conditions – different levels of infestation with diseases, pests and weeds.
Different farm structure.

5. FARMS GROWING WINTER WHEAT IN SELECTED PROVINCES (2006)
lubelskie
lodzkie
zachodnio- -pomorskie
Number of farms
97 132
30 761
8 609
Winter wheat crop area (ha)
57 597

6. WINTER WHEAT CROP – CROP AREA

7. SAMPLE SELECTION SCHEME
Optimal strata selection scheme was applied.
Each province was divided into 5 strata.
The division of the population into strata and the sample allocation among the strata was performed while applying the numeric optimization method.
Optimization criterion – minimization of the coefficient of variance for total sown area.

8. STRATA LIMITS

9. NUMBER OF FARMS WITHIN THE POPULATION AND WITHIN SAMPLE ACCORDING TO STRATA
Province
strata
h=1
h=2
h=3
h=4
h=5
total
Lubelskie Nh nh
58788
28243
9036
1022 43
97132 38 32 30 27
170
Lodzkie
17553
8483
4041
634 50
30761 37 22 31
Zachodnio- -pomorskie Nh
6185
1758
481
130 55
8609 29 25

10. DEVELOPING A NEW SYSTEM OF DATA COLLECTION
Internet-based system
Printing questionnaires with sampled farms data.
Entering data into the electronic survey format by inspector.
Feeding the survey data into the database over the internet.
Establishing communication between the inspectors and coordinators and the data administrator and project manager.
Internal Control.

11. AVERAGE PESTICIDE USAGE INDICATOR (R)
X – pesticides use (AS) in kg
Y – crop area
Sample selection for the pilot project:
Voivodship – index „w” (w = 1, 2, 3)
Stratum – index „h” (h = 1, )
Farm – index „i” (i = 1, 2, ..., nwh)
nwh – number of farms selected to the primary sample from the h-stratum of the w- voivodship

12. AVERAGE PESTICIDE USAGE INDICATOR (R) cont’d. (2)
Consistent with the sampling scheme, the estimator of parameter R is:
( i = 1, 2, … , nwh; h = 1, 2, … , 5; w = 1, 2, 3)
where:
xwhi – pesticide usage (AS) at the i-farm sampled from the h-stratum of the w- voivodship,
ywhi – winter wheat crop area at the i-farm within the h-stratum of the w- voivodship,
wwhi – weight assigned during sampling to the i- farm within the h- stratum of the w- voivodship

13. AVERAGE PESTICIDE USAGE INDICATOR (R) cont’d. (3)
Computing the weight:
( i = 1, 2, … , nwh)
gdzie:
Nwh – number of farms within the h-stratum of the w-voivodship, 
nwh – number of farms randomly drawn for the (primary) sample from the h-stratum of the w- voivodship
We use adjusted weight because of the necessity of drawing from the reserve sample due to refusal of participation in the survey or other reasons.

14. THE ADJUSTED WEIGHT The study realization is not ideal in reality.
in cases when a farm cannot be surveyed due to refusal to participate in study or similar causes the primary sample needs to be altered to include a farm from the reserve list
Primary weight wwhi is adjusted using the following multiplier mwhi :
where:
 nrwh – number of farms included in the study of the h-stratum of the w- voivodship from the reserve sample,
nzwh – number of farms surveyed (from the primary sample and the reserve sample) within the h-stratum of the w- voivodship,
nbwh – number of farms not surveyed (from the primary sample and the reserve sample) due to refusals or similar reasons

15. THE ADJUSTED WEIGHT (cont.’d)
The adjusted weight wkwhi for the i-farm surveyed within the h-stratum of the w-voivodship will be as follows:

16. AVERAGE PESTICIDE USE INDICATOR CALCULATED FOR 3 VOIVODSHIPS
lubelskie – 1.16 kg AS/ha
lodzkie – 1.32 kg AS/ha
zachodniopomorskie – 2.80 kg AS/ha
the average value of the pesticide use indicator for the three voivodships
1.69kg AS/ha

17. AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY
Method I
The voivodships in Poland would be divided into three groups, according to their farm structure (crop area allocated to winter wheat).
Each group would contain one of the three voivodships included in the pilot project (lubelskie, lodzkie, zachodniopomorskie).
For each of the three voivodships, we would compute the estimator rg which would denote pesticide usage in kg/ha.

18. AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont
AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont.’d)
Method I (cont.’d.)
We compute indicator for Poland according to the following formula
(g = 1, 2, 3)
g – voivodship group index
where:
Pg – winter wheat crop area in g-group of voivodships
P – winter wheat crop area in Poland

19. Division of voivodships into three groups
AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont.’d)
Method I (cont.’d.)
Division of voivodships into three groups
zachodnio pomorskie
lodzkie
lubelskie

20. AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont
AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont.’d)
Method II
Combine the results from the three voivodships
Divide all surveyed farms into five farm size groups:
less than 2 ha
2-5 ha
5-20 ha ha
over 150 ha
Criteria for dividing the voivodship in such a way as to even the number of surveys in each size group.

21. AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont
AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY (cont.’d)
Method II (cont.’d)
Estimator rg denoting the use of pesticides in kg/ha is calculated for each farm size group (g in this case is the number of the farm size group)
Then we calculate the usage indicator for Poland
(g = 1, 2, 3, 4, 5) – farm size group index
where:
Pg – winter wheat crop area in g-farm size group
P – winter wheat crop area in Poland

22. AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY – RESULTS
According to Method I
Pg1 = ha
Pg2 = ha
Pg3 = ha
P = – winter wheat crop area in Poland
winter wheat crop area in groups of voivodships
rPOLAND = 1.84 kg/ha
NOTE: When voivodships were grouped differently, the result was 1.93 kg/ha

23. AVERAGE PESTICIDE USE INDICATOR ESTIMATE FOR THE ENTIRE COUNTRY – RESULTS
According to Method II
Farm size group
less than 2 ha
2-5 ha
5-20 ha ha
over 150 ha
crop area in group Pg
average pesticide use in group rg
0.98
1.29
1.58
2.26
3.07
rPOLAND = 1.81 kg/ha
NOTE: When divided into different farm size groups, the result was 1.80

24. AVERAGE PESTICIDE USE INDICATOR 2003 – 2007 STUDY RESULTS
TYPE OF STUDY
2003
national monitoring by the Plant Protection and Seed Inspection Service
(2700 farms)
2005:
2002 PHARE project
(1 voivodship – 100 farms)
2007
Pesticide Indicator project – data from three voivodships
2007 Pesticide Indicator project – generalizing to the entire country according to Method I
2007 Pesticide Indicator project – generalizing to the entire country according to Method II
AVERAGE PESTICIDE USE INDICATOR
(kg of AS/ha)
1.85
2.14
1.69
1.84
1.81

25. EXAMPLES OF RESULTS AFTER ALL-COUNTRY GENERALIZATION
AVERAGE USE OF ACTIVE SUBSTANCES PER CHEMICAL GROUP
FUNGICIDES
(example: top portion of table)
Eurostat Code
Product type
Chemical group
Average use (kg/ha)
% of share in total use indicator
(data from three voivodships)
F1.2
Inorganic fungicides
Inorganic sulphur
0.172
9.36%
0.141
F2.3
Fungicides based on carbamates and dithiocarbamates
Dithiocarbamate fungicides
0.118
6.39%
0.125
F3.1
Fungicides based on benzimidazoles
Benzimidazole fungicides
7.67%
0.148
F4.1
Fungicides based on imidazoles and triazoles
Conazole fungicides
0.080
4.32%
0.075
F4.2
Imidazole fungicides
0.024
1.31%
0.023
F5.1
Fungicides based on morpholines
Morpholine fungicides
0.055
3.01%
0.049

26. EXAMPLES OF RESULTS AFTER ALL-COUNTRY GENERALIZATION
AVERAGE USE OF PESTICIDES PER TYPE
1.84 kg AS/ha

27. RATIO OF AREA TREATED WITH SELECTED ACTIVE SUBSTANCE TO TOTAL AREA TREATED (active substance area treated)
EXAMPLES – top listings from selected types
Eurostat Code
Product Type
AS Name
Ratio [%]
H6.3
herbicides
isoproturon
5.01
F3.1
fungicides
carbendazim
12.01
I1.1
insecticides
alpha-cypermethrin
1.41

28. RATIO OF AREA TREATED WITH PRODUCT TYPES TO TOTAL AREA TREATED
(active substance area treated)
Product type
Ratio [%]
Fungicides 56
Herbicides 34
Insecticides 3
Other 1
Plant growth regulators 6
Total area treated with active substances: ha

29. QUALITY OF PESTICIDE USE SURVEY
Basic parameters:
Quality of sample selection (sampling quality) – error analysis.
Completeness of survey (evaluated as good – out of 569 sampled farms, there are 29 farms not surveyed, including the reserve sample).
Technical accuracy (selection of the interviewers, data quality, data processing, calculations).

30. ERROR ANALYSIS – RESULTS
Voivodship
Average pesticide use indicator for voivodship
(kg of AS/ha]
Absolute standard error
Relative standard error [%]
lubelskie
1.1616
0.0733
6.31
lodzkie
1.3223
0.0905
6.84
zachodniopomorskie
2.8011
0.1201
4.29
TOTAL
1.6859
0.0584
3.47
NOTE:
relative standard error is lower in the zachodniopomorskie voivodship due to a high number of large-size farms within the sample and less variety in the pesticides used

31. SUMMARY
Average pesticide use indicator was calculated for winter wheat in three surveyed voivodships, using adjusted weight.
Two methods of generalizing the results for the entire country were applied.
Good consistency of the generalized results was observed with the 2003 national monitoring data.
Sampling error was determined.
The computed sampling error is low, considering the ratio of the number of farms to the number of farms growing winter wheat.
Survey quality was evaluated as good.
The right sample selection is the key element determining the outcome of the survey.

32. RECOMMENDATIONS FOR THE NATIONAL – SCALE MONITORING
optimal, stratified sampling should be used
important: sample size
number of strata
establishing the strata limits
sampling should be performed from the entire population (total number of farms)
it is necessary to define indicatores describing investigated parameters for national use
the system of data collection should be automated
data preparation and computing results from the usage studies should be automated