Technical “
glyphosate at more than 250l/ha. Since knapsack applications involve the operator carrying the necessary water on his back, there is little justification for choosing any other than the lower volume
required under the Sustainable Use Directive and saves money by reducing unnecessary herbicide use in overall spraying. Moreover, compliance is well within the reach of competent, qualified operators - the legislation brought into law is what we at Monsanto, the Amenity Forum and Amenity Assured Contractors consider best practice.” The rules apply only to spraying on non-
porous hard surfaces, which include tarmac, bitumen, block paving/pavements, crazy paving, solid wall bases and concrete. All paving is included, irrespective of gaps being filled with permeable material such as sand. Natural surfaces not intended to bear
vegetation (such as bare soil), permeable surfaces overlying soil (such as sand or gravel) and railway ballast are not covered by the rules because pesticides can naturally percolate downwards rather than running-off. Manda explains: “On hard surfaces, there is
little or no absorption, posing a high risk of run-off to the nearest drain after the first 2- 3mm of rain. It is particularly important to check herbicide product labels carefully to see if they apply to your intended target before use.”
Good spraying practice
Hard surface weed control must be achieved with spot spraying, using weed wipers or sprayers, which can be automated with infra- red weed detection units or manually operated. Suitable applicators include ATV mounted units,
Consider application volumes carefully - there is no advantage in applying
Qualified operators
Operators wishing to apply herbicides to hard surfaces are required to attend a suitable course organised through the National Proficiency Test Council, leading to PA1/6 certification in hand operated spraying. A Certificate of Competence became compulsory when spraying any approved professional pesticide, even on privately owned land, on 25th November 2015 with the end of Grandfather Rights.
The right nozzle
Always check the product label for the manufacturer’s recommended application rates and appropriate nozzles. “When spraying glyphosate products using
hydraulic nozzles choose those rated at 1.5-2.5 bar which produce an even distribution,” advises Manda. “Be careful, because many nozzles are designed to work at 3 bar or more, which is outside the label specification for Roundup products. A medium or coarse spray is required to avoid damaging drift from fine droplets. Roundup ProActive and Roundup ProVantage formulations have low drift properties built-in, producing 33% less drift than standard glyphosates through flat fan nozzles.” Low pressure, even flat fan, anvil or deflector
tips are the most suitable for a knapsack sprayer because the pattern is even, whereas standard nozzles designed for use on a boom must overlap each other for correct coverage. “There is no advantage in applying Roundup at any more than 250 l/ha and, indeed, results can actually improve in lower volumes. Since knapsack applications involve the operator carrying the necessary water on his back, there is little justification for choosing any other than the lower volumes. The lowest label water
By only treating the weed foliage itself, rather than spraying the entire area, the potential run-off is reduced by 97% once it has dried on the leaf
knapsacks, CDA and specialist ULV applicators. Ensure spraying takes place only when weeds
are actively growing (normally March to October) and is confined only to visible weeds. “By only treating the weed foliage itself
rather than spraying the entire area, the potential run-off is reduced by 97% once it has dried on the leaf,” explains Manda. “Run-off from treated leaf material is much reduced as most of the glyphosate enters the leaf within a few hours and only breaks down gradually as the plant dies and tissue rots.” Technique is also important, she points out:
“Weed detection units are ideal on ATV equipment but, when spraying manually, it is important not to stop and treat each individual weed with the standard dilution as this will result in overdosing. The trigger/switch on the sprayer should be turned on and off whilst continuing to walk.” Weeds in a 30cm swath across the kerb
edge, to include any weeds growing in the gutter on the road side, can be sprayed, but watch out for drains, Manda adds: “Whilst you should not overspray drains, you do not have to observe a 1m buffer around them.”
volume for Roundup ProVantage through a knapsack is 80l/ha,” she says. Application rate is a function of nozzle output, walking speed and swath width. “Good calibration is essential for efficient use of herbicides and, although all operators have undergone training, it is still worth emphasising the need to recalibrate whenever the product, situation or nozzle type is changed.” Manda comments: “Many people
underestimate the importance of nozzle height in accurate application. Most are designed to work at 50cm above the target, but the most comfortable working height for the operator is much more variable and is often around 35- 40cm. The swath width is dependent on this height and halving it will also halve the swath width and double the application rate.” Hard surface spot treatment rules introduced in 2012 require that roads, pavements and other impermeable surfaces can only be sprayed in 30cm bands along edges or individual weeds. Manda says: “Currently, there are no nozzles
designed to spray 30cm bands, which means nozzle height needs to be reduced to achieve the narrower width. Double dosing is a real risk, unless the sprayer is recalibrated, because more dilute spray solutions will be necessary. The Green DT 0.75 deflector nozzle needs to be at only 15cm height to deliver a 30cm band width and, being so close to the ground, makes it hard to achieve accurate coverage.” A very simple way to keep the nozzle height
correct whilst working is to attach piece of lightweight chain of the required length to the end of the hand lance and keep its end just at target height, she advises.
Always check the product label for application rates and appropriate nozzles
Suitable applicators for hard surface weed control include UTV mounted units
PC JUNE/JULY 2016 I 127
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156