Scouting Is More Than Looking For Insects

Coleus2_siktberg

Catching problems before they become problems in a greenhouse requires a trained eye and a regular routine of monitoring plant health. While scouting is most often thought of as checking for insect pests, in broader terms it means monitoring overall plant health – checking for nutrient deficiency symptoms, under or overwatering, hot spots or cold spots in the greenhouse, sanitation problems and detection of disease pathogens. Scouting is at the core of any IPM program and is an essential best management practice for greenhouse operations. While record keeping and data collection may not be on your list of favorite things to do, the headaches saved down the road by catching problems early make it well worth your time.

“It’s not just scouting for insects and diseases,” says Kelly Ivors, associate professor and extension specialist at the Department of Plant Pathology at North Carolina State University. “It’s also scouting for healthy plants. It’s checking for healthy growing conditions such as monitoring temperature.”
Ivors stresses the importance of knowing what your plants are supposed to look like.

“For instance, there’s a lot of different varieties of coleus, and sometimes it’s easy to mistake [their variegation] for a disease or nutrition problem. But that might be the way they’re supposed to look,” she says. “You really need to know what that plant is supposed to look like when you’re working with floriculture and herbaceous plants because there’s so much variety.”

Overall plant health is important because a healthy plant can ward off some of the secondary, or opportunistic pathogens, on its own. These are things that aren’t typically problems unless you have other problems, Ivors says.

“For example, there are a few species of pythium that aren’t always a problem, but they can be if fertility is off, if there’s salt damage or if there are some odd temperature fluctuations,” she says. “You can [also] get botrytis really badly in a greenhouse if you have wounded plant tissue from cold temperatures.”

While scouting for insects may often involve measuring levels of the population and keeping it below acceptable thresholds, once a potential disease problem is identified, action is often taken early because diseases can spread so quickly.

“Look for wilting, for stunting, for yellowing leaves,” Ivors says. “Anything that looks abnormal.” Leaves that are off-color or have spotting are also signs of a problem, she says.

Once you notice something odd, it’s important to get the correct diagnosis, which often involves sending samples to a plant pest and disease clinic.

“Half the things we get in our clinic aren’t even diseases or insects – they’re cultural things. But growers are willing to send samples in to get that confirmed because they know it could be a big problem if it is a disease,” Ivors says.

The location and spread of symptoms often offer a clue to the type of problem.

“You have to look at the consistency of the problem across the entire crop,” Ivors says. “If it’s affecting the whole crop, it’s probably a cultural problem. Often diseases don’t show up with that kind of uniformity unless perhaps you propagated from infected material.”

Ivors points out that this is where good record keeping becomes important, stating that for diseases, comparing the time of day, the symptoms and location of the problem can then be compared with pest control and fertilizer applications, as well as with temperature and humidity records to see if there might be a connection, such as a phytotoxicity issue with a plant growth regulator or fungicide.

Diligent, regular scouting by someone trained in what to look for buys time and allows more options for control, Ivor says, because you can prevent the problem rather than trying to apply something curative.

“A lot of fungicides do not have curative activity. If you don’t scout and don’t catch the problem until it’s at a very high level, it’s very difficult to control at that point,” she says.

Ivors cites powdery mildew as a good example of this.

“There are a lot of products that are very good at protecting plants that aren’t yet infected,” she says. “But it’s very difficult to wipe out the disease once it’s been established.”

Leave a Reply

3 comments on “Scouting Is More Than Looking For Insects

  1. I enjoyed this article. I am a Horticulture instructor at Fox Valley Technical College, Appleton, WI. I am teaching a Plant Diagnostics course and I have been going over the importance of scouting with my class. It is good for the students to see another opinion that backs up what I tell them. Thanks for your article, I look forward to many more.

  2. When scouting it's also important to use your nose to smell for the frass of the fern worms in high up baskets and to detect natural gas leaks that might be occurring in the greenhouse. Also use your eyes to watch folks water to see if fertilizer dye is coming through the line. A jar test is valuable too to see if water is clear or blue.

Latest Stories
Laura Drotleff

December 6, 2016

Are You Driving Young Growers Away? [Opinion]

In a time when the industry is facing a critical shortage of both labor and skilled, educated growers, it's important that grower operations don't unwittingly turn candidates off to a career at their business or in the industry in general. Take a closer look at your hiring practices to ensure you are being inclusive and not breaking any laws.

Read More

December 6, 2016

America In Bloom Moves Forward With New Management Comp…

Effective Jan. 1, 2017, management of America In Bloom will transition from AmericanHort to Second Wind Management, which is owned by long-time AIB Executive Director Laura Kunkle.

Read More
bailey-nurseries-team-feature

December 5, 2016

How Bailey Nurseries Has Found Solutions To The Labor S…

A changing seasonal workforce led this Minnesota-based company to explore new labor sources through the H-2A program and refugee organizations, and it’s working out for the better.

Read More
mycoapply-from-mycorrhizal-applications-feature

December 5, 2016

New Growing Media Advancements Giving Growers More Opti…

With innovative, sustainable growing media components, growers will be able to improve plant health, achieve consistency among crops, save money, and reduce inputs, while saving space on storage.

Read More

December 5, 2016

Benary’s Jennifer Calhoun: How We Can Make Plants…

I see one main issue facing our industry in getting more people to buy plants — we assume that the way we used to sell plants is the way millennials will want to buy them. Nothing could be further from the truth. We sell plants in small packs that you plant in a hole in your garden, with a generic label that says “blooms all season.” Millennials don’t have gardens, so they want a plant they can put on their fourth floor apartment balcony, or better yet on a shelf in their living room near a window.  We give them too little information to help them be successful under those circumstances. But what we don’t realize is that if the plant dies, they feel personally responsible for killing another living thing which is so painful that they would prefer not to take the chance a second time. If we sold […]

Read More

December 5, 2016

A Visual Guide To Garden Retail Merchandising

Antje Verstl, a German visual merchandiser who has worked with many high level garden retailers in Europe, has a lot of practical, and inspirational advice on how to transform your plant yard into an exciting place to shop. Take a look at this gallery, and enjoy a visual guide from Verstl. Her book, “Eagle & Frog!,” is now available for purchase by an American market through her website.

Read More
mikaela-hermstedt-penn-state-university

December 4, 2016

Shinoda Foundation Names Penn State Horticulture Major …

Mikaela Hermstedt, a 21-year-old senior from Lincoln, DE, plans to pursue a career in commercial greenhouse production of flowering plants.

Read More
all-america-selections-new-website-home-page

December 3, 2016

New Mobile Responsive Website From All-America Selectio…

All-America Selections has launched a newly redesigned and revamped mobile-responsive website that includes a more attractive design, enhanced search tools, and easier and simpler navigation.

Read More
Sea Breeze Catharanthus combo

December 2, 2016

Four Mixed Container Trends To Watch

Mixed containers are still one of the best-selling SKUs at retail. Pay attention to these four trends that are making their mark on multi-liner mixes and combination containers.

Read More
kelly-norris

December 2, 2016

Kelly Norris: How The “Me Too” Philosophy Affects Plant…

When you’re selling the exact same thing as everyone else, it’s unrealistic to expect customers to buy only from you.

Read More
mcconkey-plastic-shelves-feature

December 1, 2016

How Color Point Is Stopping Cart Theft With Plastic She…

Plastic shelving on carts acts as a deterrent to theft, and employees enjoy the benefits of being able to handle the racks without difficulty or injuries.

Read More
oasis-water-valve-feature

November 30, 2016

How You Can Water Plants Based On Basket Weight

The Oasis from Control Dekk is designed to reduce water use by giving baskets the exact amount of water they need.

Read More

November 29, 2016

How Changes In Plant Patent Law Could Affect Your Varie…

There is an ongoing discussion happening among plant genetics companies about the current laws and ethics of plant breeding, and what the future holds for the improved lawful protection of genetics.

Read More
foxglove-aphid

November 29, 2016

How Greenhouse Growers Can Manage The Foxglove Aphid

Recent research is shedding new light on the foxglove aphid. Understanding host plants, identification, and biology will help growers deal with this pest.

Read More
endless-summer

November 29, 2016

Endless Summer Hydrangeas Will Soon Feature New Identit…

Bailey Nurseries, which first introduced the reblooming hydrangea a decade ago, says the new identity will feature a more contemporary look to appeal to current and future gardeners.

Read More
Trays move on an overhead conveyor to the end of the production line, where workers carefully pack the cleaned, sized, graded, counted and sorted Calla tubers

November 29, 2016

Texas Judge Halts Overtime Rule; Here’s What It Means F…

According to Craig Regelbrugge at AmericanHort, the injunction against the overtime rule is welcome news for horticulture.

Read More

November 29, 2016

How The Industry Is Ensuring Consumer Success With Plan…

Greenhouse Grower RETAILING reached out to growers and suppliers for their ideas on how to attract and keep new plant customers. Here's what they had to say about ensuring gardening success.

Read More

November 29, 2016

Heroes To Hives Seeks Veterans For Beekeeping Training

Michigan State University is bringing together two great causes of our times — supporting vets and boosting pollinators — in its new program aimed at teaching professional beekeeping to former soldiers.

Read More
[gravityform id="35" title="false" description="false"]