R3103 February ‘18
Q1. a) Describe the damage caused by EACH of the following pests:
i) Peach Potato Aphid; 2 marks
ii) Vine Weevil; 2 marks
iii) Stem and Bulb Eelworm 2 marks
b) Describe TWO distinct control methods for Peach Potato Aphid. 4 marks
This question relates to the following part of the syllabus:
1.1 Describe symptoms and damage caused by a range of pests, diseases and weeds in specific horticultural situations.
Pests: Codling moth, Two spotted spider mite, Peach potato aphid, Horse chestnut leaf mining moth, Vine weevil, Mealybug, Western flower thrips, Stem and bulb eelworm
2.1 State a range of appropriate methods for control of pests, diseases and weeds.
To include: physical, cultural, chemical (including partial sterilisation of soils and other media), biological for each of the pests, diseases and weeds.
Sources of information e.g. current UK Pesticides Guide.
Define Integrated Pest Management.
Review the use of Integrated Pest Management in horticultural situations:
Explain what is meant by ‘Economic Damage threshold’
Appropriate selection of integrated control methods for pests, diseases and weeds listed in1.1.
Part a) is a straightforward question which relies on knowledge of the different types of damage caused by the range of pests listed in the syllabus. The examiner’s comments state that the first two parts were well answered, but ‘fewer candidates gained full marks for stem and bulb eelworm’.
As the question asks you to ‘describe’ a reasonable amount of detail is required. The examiner’s comments explain that as there was an allocation of two marks per pest, it was expected that two distinct symptoms per pest were required. It was also explained that vague answers weren’t given marks. This included terms such as ‘ lack of vigour, poor growth, death of plants, rotting bulbs’ which all needed further explanation to relate them to the specific pest to gain marks.
For stem and bulb eelworm the examiner’s comments suggest important points as ‘infested bulbs becoming soft at the neck and when cut open displaying brown rings of dead tissue’.
For part b) it is very important to take note of the word ‘distinct’. This is quite often used in exam questions and you should make sure you give very different points for this. In the same way, if a question asks for different methods/reasons etc. make sure your examples are very different.
In this case if, for example, two biological control methods, or two physical control methods were given these were not considered to be distinct and marks would be lost.
For chemical control the name of a specific product with active ingredient, timing and method of application was expected. For physical control using a jet of water to wash the aphids off was given as an example. For biological control the name and nature of the predator was expected, e.g. the parasitic wasp Aphidoletes. The time and method of encouraging native biological controls into the garden should also be included.