In order to effectively monitor for pests and diseases, you need an effective system based on the specific needs of your farm.
You should first have a clear picture of:
- which diseases and pests you are tracking
- what decisions you want to be able to make based on the results of the monitoring
- what data need to be collected in order to make those decisions
You then need a system that will enable you to easily collect the necessary information and allow you to use it to make decisions. You also should decide if you will manage these details on your own, include other staff members, or hire a consultant.
Unless you are monitoring spray effectiveness or pest levels, routine spraying will likely provide inconsistent results, cost more of your time and money, and may even result in higher resistance levels where whitefly and WFT are problematic.
Identifying changes in both beneficial and pest insect activity in and around your crops is the most effective way to manage pests and minimize damage levels. The single way to gather pertinent information and make the most appropriate response to changes in insect levels is crop monitoring, the core of crop protection, whether you are using chemical or non-chemical techniques.
Establishing an appropriate monitoring program is likely the most time-intensive, complex portion of any IPM system, but it is a critical tool in risk management when it comes to the protection of every other investment made in the business. Once the initial set-up is completed properly, adjusted, and maintained, the system rapidly becomes effective and easy to run.
The simple introduction of a suitable monitoring program will help you identify previously undiscovered weaknesses in your pest control methods, decrease crop losses, and reduce your costs for unnecessary chemicals. Accurate monitoring of crops is critical if you also plan to introduce beneficial insects into your methods of pest control.
What growers have said:
ThiVu: I do much less spraying now that I check the crop first. I am much happier working in the crop without the chemicals there all the time and I save a lot of time not spraying.
Emmanual Cafkacis: You got to know what is going on in the crop. Unless you have a good look you can’t tell. I’ve saved a lot of money now that I know what to look for. Its taken out a lot of the guesswork.
The following describes two of the common techniques that are used in a monitoring system, yellow sticky traps and plant checks, and how the data collected can be applied to making decisions, particularly with respect to Western Flower Thrips.
Sticky cards or traps are a useful way to keep an eye on flying insect pests like whitefly, aphids, and thrips, which are attracted to the color of the traps in the same way as yellow and white flowers. Whitefly, aphids, and thrips are all attracted to yellow traps, but thrips are also drawn in by blue and white. These traps are helpful in detecting the presence of flying insects in the cropping area and are also useful in monitoring pest levels in the crop. Also, they allow for the collection of insect samples of thrips and other species that can be sent away for identification. However, such traps do not give the full scope of pest presence within crops: juvenile non-flying stages (eggs, pupae, and larvae, if coverage is poor) might not be killed by spray applications but still will not be present on the traps, and adult insects may infest the crop after flying in.
Your traps should be checked or changed at least once a week. The traps should be located just above the plants’ growing tips in order to trap insects hovering above them, and so that the traps don’t get stuck and lost within the crop. These traps can easily be inspected without the help of magnification tools (to get a basic idea of variety and number of pests present), with a magnifying glass (to determine exactly how many of each insect species are present), or with a microscope (to ascertain exactly which species of each insect variety have been trapped). It is critical to take note of any changes and, if Western Flower Thrips are of particular concern, to send the traps for further insect identification. As an estimate is provided with respect to any changes in pest counts for various species, it will provide useful information with respect to the level of threat to crops and what action, if any, you should take to correct the problem.
Taking a sample of leaves and flowers in your crop will give you much more information than a sticky trap, such as:
- the absence or presence and amounts of eggs, larvae, and pupae (non-flying juvenile stages)
- the absence or presence and amounts of mites, snails, and so on (non-flying adult stages)
- the early stages of pest damage and its extent
Such information provides much more powerful assessment with respect to pest levels, more accurate prediction of trends, and the ability to ascertain the effectiveness of any control measures in use. These details are necessary for making appropriate decisions and following up on any observed results. This sample and its data will not only provide specific details regarding the behavior of pests but will also help to make decisions about the use of beneficial insects to manage them. As you discover which pests are a problem – and thus, where they feed, hide, and breed – you will know whether to check leaves, flowers, fruit, and so on. The frequency, pattern, and depth of your sampling will depend on your crops, the time of year, the pests of concern, and the beneficial insects that are of interest.
Any weeds located near your crops and farm will see a large build-up of insects in the spring. An inspection of those weeds will give you an indicator of the progression of local pest infestation, though it would be better to remove weeds before pests have the opportunity to increase in numbers.