This one is from R3102 Feb 2019, Q1:
Describe the weed control measures available to organic gardeners to control:
i) ONE NAMED annual weed; 5 marks
ii) ONE NAMED perennial weed. 5 marks
This question relates to the following part of the syllabus:
Outcome 5. Understand organic growing.
5.3 Identify management techniques available to the organic grower.
Describe organic practices to control ONE annual & ONE perennial weed, aphids, caterpillars, potato blight and apple scab.
This question is a very straightforward one directly related to the syllabus. As there are five marks for each part a lot of detail is required for each answer.
Botanical names are needed for each plant example. An example for an annual weed is Urtica urens;, an example of a perennial weed is Elymus repens.
For part i), the examiners’ comments suggest one suitable method as ‘the use of mechanical control measures, using a sharp hoe, on a dry sunny day to aid the dessication of the annual weed’. Other suitable answers are suggested as ‘the use of organic mulches, such as bark, the mowing or cutting of weeds on a regular basis in turf, the use of chickens to grub out weeds, the use of horticultural techniques such as stale seed bed, the use of ground cover planting, or the close spacing of crops to shade out weeds’. (On a practical note, chickens will grub out all sorts of plants and not just weeds!)
An example of the technical detail needed for an answer on the control of a perennial weed is given as ‘the use of a sharp hoe, on a dry sunny day to aid in dessication of the perennial weed, on a regular basis to ensure the depletion of the carbohydrate reserve in the root tissue’. Further methods suggested for part ii) were ‘the removal of the weed by digging, ensuring that the entire root system has been removed, the use of landscape fabrics or other light excluding mulches to exhaust the carbohydrate supply in root tissue, the regular use of thermal weeders to burn off top growth, regular rotovating or cultivation of an area, or the development of garden weed management plan bringing a range of suitable techniques together’.
It can be seen that it is important to make the answers distinct for the annual and perennial weeds, indicating that you understand the life cycles of the weeds and how this impacts on control methods. A further point that could be made is the importance of controlling weeds before they flower. This is particularly important for annual weeds that can produce vast quantities of seed.