Mastering the basics

Features - Pest & Disease

Every greenhouse’s scouting program is different, but the most important part of any program is sticking to it.

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Regular scouting, mixing up the scouting pattern and tracking pests and diseases over time are some of best practices for growers.
Photo courtesy of Jeremy Jubenville
For greenhouse owners, pest scouting is an important task that is sometimes forgotten or not done regularly enough to make an impact. Here, three industry experts offer their advice on how to make a scouting program stick and make it work for your business.

Nancy Rechcigl

Technical field manager, Syngenta, 30-plus years of industry experience

The very first thing is to have a dedicated person for scouting. Everyone that’s working in the greenhouse or nursery should have eyes on the crop, but having someone who is regularly dedicated to scouting the crop will find problems earlier as opposed to really seeing the symptoms down the road. When you have a scout, and you have a good scouting program, those scouts will find those problems — pests or disease — earlier. And that means corrective actions can be taken faster and that probably means fewer applications have to be made to correct the problem. It keeps the quality of the crop in a better condition. ... The other problem with not having a dedicated person is that people working directly with the crop have other duties — fertilizing, planting, etc. They can’t do a thorough job.

The second thing would be to have a plan of how you’re going to monitor the crop. Have a plan of how you’re going to approach it. Know where you’re going to start scouting and plan to alternate your scouting pattern every week, or at least every two weeks, so that you’re covering an entire area and are keeping your inspection random. ... It’s always good to carry some flags or stakes or something so that when you come across a problem in the greenhouse, you can flag it. That way, you can be sure that when you’re going to go in and do a treatment, you’re going to do a thorough job. And that makes it easier to go back and re-check the area to make sure you did a thorough job.

Jeremy Jubenville

Floriculture and greenhouse educator —Southwest Michigan, Michigan State University, 10-plus years of industry experience

There are a couple of things I think are really helpful. You should create a map of your facility — graph paper helps. And you should take that along with you as you scout, probably once a week. Some people forget to do that. I recommend using pen and paper for this because I’ve done it digitally or seen other people do it digitally. It doesn’t really stick, and they get lazy with it. Some other common pitfalls are moving too fast through the crop, misdiagnosing a disease or physiological disorder and misidentifying an insect pest. This is especially important when using biological control.

Make sure that you’re recording this in a spreadsheet and tracking numbers for different locations. This is especially important for something like thrips. When you do that, you can track trends over time. That way you know if they are creeping up, if they are spreading throughout the crop. You won’t know if you’re not keeping track of it. Sticky cards are a great tool too.

Using sticky cards, taking notes while scouting and marking spots to revisit with stakes are some of many tools and tricks growers can use to boost their scouting program.
Photo courtesy of Jeremy Jubenville

Doug VanGundy

Vice president of R&D, Central Life Sciences, 30-plus years of industry experience

Know what you’re doing — it’s got to be specific knowledge. And know the pest spectrum for each kind of plant material that you’re growing. If it’s a plant material that has a propensity towards aphids, then that’s what to look for.

Most greenhouses, in my experience, grow a variety of different plants and it takes somebody — I think it should be a dedicated individual — to be the scout. Some of these greenhouses are huge, too, so they might need more than one person dedicated to that.

It’s going to take more than one product to combat the whole pest spectrum. A grower could be dealing with mites and aphids and thrips, and they’ll need different kinds of products from miticides to insect growth regulators to systemic products to quick knockdown products. ... Identifying the pest is important, as is knowing the economic threshold of combating that pest. If you see one aphid, it’s probably not time to spray, but it gives you a heads up to say, “Well, I’ve got one. I better look around more in [the] greenhouse and look at more plants to see if they have a problem.” IPM and timing of that spray is going to be so important. ... Some years are going to be worse than others and that makes that scouting program so important. If you have a history of spider mites in your greenhouse, then having products on hand to take care of that makes sense. But these days, if you have a distributor nearby or someone that [you] have a relationship [with], you can get what you need fairly quickly.