- Integrated Pest Management (IPM): an introduction
IPM means the careful consideration of all available pest control techniques and subsequent integration of appropriate measures that discourage the development of pest populations and keep pesticides and other interventions to levels that are economically justified and reduce or minimise risks to human health and the environment. IPM emphasises the growth of healthy crops with the least possible disruption to agro-ecosystems and encourages natural pest control mechanisms. – FAO.Why do we need it?
Global trade routes have enabled the transport of people and goods, including pests, easier than ever before. As a result:
- Globally, there has been an exponential increase in pest and disease incidents.
- A trend mirrored in South Africa when looking at the recorded pest and pathogens on Eucalyptus since its introduction.
At the same time:
- The number of chemical pesticides available, particularly in the forestry industry, is continuously being reduced.
As a result of:
Factors influencing IPM
- Increased awareness and understanding about the human health and environmental implications of certain pesticides.
- Increased demand for end-products that are less reliant on chemical inputs during their production.
- Availability of suitable chemical products which are socially and environmentally acceptable.
- Increased demand for certified products, from international certification bodies such as Forest Stewardship Council® (FSC®) and Programme for Endorsement of Forest Certification (PEFC) who have stringent guidelines regarding chemical pesticides and their use.
There are a number of variable that influence the ETL upon which IPM strategy are based:
- Tree species, end-products and demand
- Pest species
- Control methods being implemented
- Climate and prevailing weather conditions
- Stage in the growing season
- Market change - i.e. economic fluctuations
With so many variables the ETL needs constant revision.
click here to download SOP Introducing IPM infographic as a .PDF
Many foresters have large land-holdings under their responsibility and simply cannot check every compartment – this makes prioritised monitoring vital. To do this, the forester has to understand their plantations: the age, the species planted and the persistent weather conditions, as well as the current pest and pathogen threats. This enables them to prioritise compartments within the plantation for monitoring purposes.
- Compartment age/life cycle Trees are susceptible to different pests and pathogens at different growth stages in their lives. For example, there are establishment pests such as cutworm and white grub that feed on young seedlings, whereas Thaumastocoris attacks older trees. However, there are some pests and pathogens which attack trees at all stages under the right conditions.
- Tree species. All tree species are susceptible to pests and pathogens. However, certain pests or pathogens only attack certain species or genera. One of the aims of tree breeding is to hybridise species to be more tolerant to pests/pathogens.
- Pest/disease prevalence Certain pests and pathogens are more prevalent during certain times of the year, in certain locations or under certain conditions – planning needs to factor this in and also requires a good knowledge of pests, their life cycle and whether outbreaks are seasonal or random.
- Weather conditions Outbreaks of certain pests/pathogens often occur after unusual weather conditions. There are also certain pests/pathogens which can be linked to fire, frost or other abiotic factors which make the trees more susceptible. Wattle rust is a good example: it loves cool misty conditions. Drought conditions result in outbreaks due to the trees being stressed and the pest/pathogen is a secondary occurrence.
For a successful monitoring programme, a forester or nurseryperson needs to be adequately prepared.
- Pest identification – field guides with colour photos clearly depicting pest at all life stages; you may need a handheld lens to clearly identify certain pests/pathogens.
- Specimen collection equipment – samples of insects and/or damaged material can be collected and sent to the Tree Protective Cooperative Programme (TPCP) diagnostic clinic for identification. Ideally, you will need a range of paper and zip-lock bags, sample bottles with ethanol, permanent marker and or pencil, camera for photos, GPS for co-ordinates, cooler box with ice bricks to keep samples cool, scissors, secateurs, saw, black bags.
- PPE – in accordance of the companies specifications as they all have their own PPE requirements.
- Water – dehydration is a real risk when collecting samples.
Data collection is critical in monitoring and the management of pests and pathogens. The data can help to identify the pest/pathogen using the pest ID matrix. It can also be used to help predict the occurrence of future outbreaks.
Data should include:
- Location information – Farm/nursery name, compartment number, GPS co-ordinates
- Tree species/hybrid/clone and age
- Pest or pathogen species, if present
- Damage or symptoms of pest presence – sometimes pests are not present, only visible damage or tree showing symptoms of pest presence. In these cases, damage or tree symptoms can be used to identify most likely culprit. One needs to look for egg sacks, larvae, physical damage, resin, galls etc.
- Distribution – Localised (single plant), scattered plants, general
- % of plants affected
- Damage history – date problem was first noticed and any recurrences
- Persistent/unusual weather conditions.
- Compartment conditions – slope, previous damage (e.g. pest, pathogen, fire, frost etc.)
- Additional information – any information about planting conditions, pruning, fungicide/herbicide applied, changes to fertigation or routine disruptions etc.
click here to download Integrated Pest Management SOP infographic as a .PDF