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Our method divides the whole site into estimated areas of bad, medium, and light infestation, and then averages out the density of the weed problem in those areas. We do this by measuring 5' X 5' sample plots in typical examples of those three grades of weed density. We count the weeds in the plots (and average them), to give us figures which we call 'the average density per 25m.sq'. We sometimes count several plots of similar density to arrive at this figure.
Each density is given an estimated total area within the site (and of course a site map can help with this). We can then refer to ourwork rate predictor charts for the target weed, which will give us the time that is taken by one man to clear one acre, at various weed densities. They also offer a costing based on £6 per hour.
Another method is to take tools onto your site and find out how long it takes you to clear a chosen area. All jobs have variable conditions, affecting work rates, but make sure you are practiced before you do the sums. The repetitive nature of the work means the knack of using a Lazy Dog Tool is usually acquired quite quickly before.
Other costs to consider:
|
| 1) |
Allow time for removal & burning/ hot-composting of weeds. |
| 2) |
Allow 30 minutes for paid breaks in a seven hour day (our normal practice) |
| 3) |
Allow for possible transport or accommodation costs of gangs |
| 4) |
Allow for the cost of the tools. |
|
| Factors affecting work rate |
| 1) |
Terrain: Fastest on flat sites. Slower on steep and uneven banksides. |
| 2) |
Length & type of surrounding vegetation. Fastest in well grazed grassland, in which weeds are most easily located . Slower among thick vegetation. |
| 3) |
Soil Moisture: (this is usually essential). Fastest in cool air and moist soil conditions. Slower in dry sunny weather. |
| 4) |
Fitness & team spirit: Choose a workforce that gets on socially and is reasonably strong. |
| 5) |
Method : be methodical and target areas for completion before the breaks. We sometimes divide up flat or open sites by driving a van up and down to leave wheelings that give 4 or 5 metre corridoors of responsibility to each gang member. |
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| CLICK A BULLETED ITEM FROM THE LIST BELOW TO VIEW THE WORK-RATE PREDICTOR CHARTS FOR : |
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| Work Rate Predictor - Ragwort <<Back |
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Average ragwort density per 25m2
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Number of plants extracted per minute*
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1 acre * cleared (mins) slowest rate for lower density
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1 acre * cleared (mins) slowest rate for higher density |
Cost range @ £6.00 per hour of ragwort extraction over 1 acre
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| 1 - 5 |
2 - 5 |
81 |
270 |
£8.10 - £27.00 |
| 5 - 10 |
3 - 6 |
270 |
405 |
£27.00 - £40.50 |
| 10 - 20 |
4 - 7 |
405 |
648 |
£40.50 - £64.80 |
| 20 - 30 |
5 - 8 |
648 |
809 |
£64.80 - £80.90 |
| 30 - 40 |
6 - 9 |
809 |
1079 |
£80.90 - £107.90 |
| 40 - 50 |
6 - 10 |
1079 |
1349 |
£107.90 - £134.90 |
|
| * Number of plants extracted per minute based on timings during a 7hour day with 15 minute rests every 2hrs and an hour lunch break with a relatively fit, tool operator.
*( Multiply by 2.47 for man hours per hectare )
Figures based on working field trials and contracts which have been on going since 1998.
Compiled by J.Trevelyan BSc (Hons) Plant and Soil Science. University of Aberdeen
.
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| Work Rate Predictor - Docks <<Back |
| for site specific work-rates, using the Lazy Dog. The size and age of dock plants, together with ground and surrounding vegetation, all influence working rates. |
| 1) |
Seedling docks - one year old. Smaller less well established plants with tap root less than an inch in diameter. Moist conditions. Easily visible. |
| 2) |
Mixed seedling and one to five year old docks. Well established mature dock plants with well formed, often forked tap root between 1-2 inches in diameter. Moist conditions. Easily visible. |
| 3) |
Mostly older or larger established docks often growing in multi-stem clusters with multiple, large 1-4 inch diameter forked, tap roots. Moist conditions. Easily visible. |
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| Dock type |
No of docks extracted per minute |
Man hours to extract docks from 1 acre * at different densities
|
| 5 per 25m2 |
10 per 25m2 |
20 per 25m2 |
| 1 |
4 |
3.3 hrs |
6.7 hrs |
13.3 hrs |
| 2 |
2 |
6.7 hrs |
13.3 hrs |
26.7 hrs |
| 3 |
1 |
13.3 hrs |
26.7 hrs |
53.3 hrs |
|
| *( Multiply by 2.47 for man hours per hectare )
Figures based on working field trials and contracts which have been on going since 1998.
Compiled by J.Trevelyan BSc (Hons) Plant and Soil Science. University of Aberdeen
.
|
| Work Rate Predictor - Spear Thistle<<Back |
| for site specific work-rates, using the Lazy Dog |
|
Average thistle density per 25m2
|
Number of plants extracted per minute*
|
1 acre * cleared (mins)
Range - from slowest rate at low density to slow rate for high density
|
Cost range @ £6.00 per hour of thistle extraction over 1 acre
|
| 1 - 5 |
3 - 6 |
54 - 135 (mins) |
£5.40 - £13.50 |
| 5 - 10 |
6 - 10 |
135 - 202 (mins) |
£13.50 - £20.20 |
| 10 - 20 |
8 - 12 |
202 - 324 (mins) |
£20.20 - £32.40 |
| 20 - 30 |
10 - 14 |
324 - 486 (mins) |
£32.40 - £48.60 |
| 30 - 40 |
10 - 14 |
486 - 648 (mins) |
£48.60 - £64.80 |
| 40 - 50 |
10 - 14 |
648 - 809 (mins) |
£64.80 - £80.90 |
| |
|
| *( Multiply by 2.47 for timings/ costs per hectare )
Figures based on working field trials and contracts which have been on going since 1998.
Compiled by J.Trevelyan BSc (Hons) Plant and Soil Science. University of Aberdeen
.
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| Controlling Canadian or Creeping thistle with the new Chisel Hoe <<Back |
| (designed & made by Lazy Dog Tools Ltd) |
|
Average creeping thistle density per 25m2
|
Low and high total number of plants per 1 acre (4047m2)
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Number of plants extracted per minute*
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1 acre * cleared (mins)
Range - from slowest rate at low density to slowest rate at high density
|
Cost range @ £6.00 per hour of creeping thistle extraction over 1 acre
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| 1 - 5 |
162 - 809 |
5 - 10 |
32 - 162 (mins) |
£3.20 - £16.20 |
| 5 - 10 |
809 -1619 |
10 - 15 |
81 - 162 (mins) |
£8.10 - £16.20 |
| 10 - 20 |
1619 - 3238 |
15 - 20 |
108 - 216 (mins) |
£10.80 - £21.16 |
| 20 - 30 |
3238 - 4856 |
20 - 25 |
162 - 243 (mins) |
£16.20 - £24.30 |
| 30 - 40 |
4856 - 6475 |
25 - 30 |
194 - 260 (mins) |
£19.40 - £26.00 |
| 40 - 50 |
6475 - 8094 |
25 - 30 |
260 - 324 (mins) |
£26.00 - £32.40 |
| 50 - 100 |
8094 - 16188 |
25 - 30 |
324 - 648 (mins) |
£32.40 - £64.80 |
| 100 - 200 |
16188 - 32376 |
25 - 30 |
648 - 1295 (mins) |
£64.80 - £129.50 |
| 200 - 300 |
32376 - 48564 |
25 - 30 |
1295 - 1943 (mins) |
£129.50 - £194.30 |
| 300 - 400 |
48564 -64752 |
25 - 30 |
1943 - 2590 (mins) |
£194.30 - £259.00 |
| 400-500 |
64752 - 80940 |
25 - 30 |
2590 - 3238 (mins) |
£259.00 - £323.80 |
| 500 - 600 |
80940 - 97128 |
25 - 30 |
3238 - 3886 (mins) |
£323.80 - £388.60 |
| 600 - 700 |
97128 - 113316 |
25 - 30 |
3886 - 4533 (mins) |
£388.60 - £443.30 |
| 700 - 800 |
113316 - 29504 |
25 - 30 |
4533 - 5180 (mins) |
£453.30 - £518.00 |
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| These higher figures are rare, sometimes encountered in cultivated land where repeated & deep rotovation had been tried. (a big mistake).Rotovators can only be used very carefully on the surface inch of soil, with this weed |