Making The Case For Pesticide Use

Those of us who study issues related to ornamental plant production are well aware of the trend or demand toward reducing pesticide (insecticide and miticide) use based on the concerns associated with harmful effects to humans, animals, water and the environment. Federal and state laws or regulations limiting the number and types of pesticides available to greenhouse producers have challenged the ornamental industry, and ongoing reviews of pesticide classes like the pyrethroids and neonicotinoids may further limit the number available in the future.

Our industry, however, can make a good case for the appropriate and proper use of both conventional and alternative pesticides in greenhouse production systems where alternative pest management strategies may not result in a saleable crop.

Need For Quality

First, it is critical a quality crop be produced to successfully compete in the global marketplace. The value and quality of the crop are based on aesthetics, and consumer demand for high-quality ornamental crops is high. To that end, more attention needs to be focused on arthropod pests (insects and mites) and the potential economic losses they can cause.

In addition, predicting future crop production, which can take a year or more, is based on the market. However, a single arthropod pest population can render a crop unmarketable at any point during the production cycle. Therefore, most greenhouse producers cannot wait for arthropod pest populations to build up to threshold levels that are common in agriculture. So in actuality, pesticides serve as an “insurance policy” to manage or regulate the diversity of arthropod pests.

In contrast to the common monoculture production systems in agriculture, the diversity of plant material grown in greenhouse production systems lends itself to a greater arthropod pest complex. Therefore, the challenge is protecting an aesthetically valuable crop from a broad spectrum of arthropod pests, including aphids, thrips, mites, whiteflies, mealybugs and fungus gnats.

The intensive nature of production and aesthetic quality requirements of producing ornamental plants makes the use of pesticides imperative to the ornamental industry. The use of pesticides also allows greenhouse producers to successfully compete in national and international markets.

Fear Of Pesticides

The mere mention of the term “pesticides” to the general public unfortunately conjures up images associated with environmental and groundwater contamination, harmful effects to humans and animals, negative effects on natural enemies such as parasitoids and predators, and concerns regarding pesticide resistance. It has been proposed that no chemical, whether natural or synthetic, may be considered completely “safe.”

Although these are valid concerns, the benefits of applying pesticides (both conventional and alternative) correctly are rarely if ever acknowledged. The advantages of using pesticides in food production are well known, accepted and generally taken for granted. The benefits of pesticides, however, as it pertains to the production of greenhouse-grown crops is seldom presented or brought to the attention of the end-users: consumers or homeowners.

Benefits Of Pesticides

In addition to their selectivity, many of the newer alternative pesticides have short residual activity, are less toxic to humans and mammals, and require less active ingredient in order to achieve “control.” They also leave minimal hazardous residues, are less harmful to the environment and have minimal direct and/or indirect impact on natural enemies, including parasitoids and predators. In fact, a number of commercially available alternative pesticides may be used in conjunction with natural enemies. Research has demonstrated certain alternative pesticides are compatible with parasitoids, predatory mites, predatory bugs, green lacewings and ladybird beetles.

Pesticides allow greenhouse producers to control or regulate a myriad of arthropod pests, which may be less expensive and more practical than other pest management options. For example, the costs associated with using the parasitoid, Encarsia formosa for regulation of the sweet potato whitefly B-biotype, Bemisia tabaci (informally called the silverleaf whitefly) on poinsettia (Euphorbia pulcherrima) were more than 300 percent higher than applying the systemic insecticide, imidacloprid.

A single application of a systemic insecticide may provide “control” or regulation of several different phloem-feeding insect pests such as aphids, whiteflies and mealybugs, and any residues may continue to kill insect pests for days or even weeks, depending on the physical and molecular characteristics of the pesticide applied.

The use of biological control or natural enemies may be a viable pest management option in some cases, depending on the arthropod pest. However, sole use of either parasitoids or predators cannot be relied upon to provide sufficient regulation of most arthropod pest populations, particularly if multiple arthropod pests on many different crops are involved. In addition, the presence of the natural enemy or any byproducts may affect sales.

Generally, customers shy away from plants that have an insect or mite on them regardless of whether it is a pest or a beneficial–whereas a pesticide may be able to regulate a multitude of arthropod pests on many crops simultaneously.
Pesticides may also be needed in order to maintain phytosanitary requirements when marketing plants out of state or out of the country. One of the most significant consequences associated with the movement of ornamental plants is the problem regarding invasive or exotic arthropod pest species.

For example, insect and mite pests, and even diseases, which are not indigenous to the United States but are known to be exotic arthropod pests in exporting countries, are more likely to be introduced into new areas where certain arthropod pests do not exist. This is a major concern to federal and state agencies responsible for excluding or eradicating exotic arthropod pests. As such, measures often recommended to deal with exotic arthropod pests include stringent phytosanitary practices, where pesticide use may be imperative. This then allows the continued export and import of ornamental plant material among countries.

Most greenhouse-grown crops are susceptible to multiple arthropod pests including aphids, whiteflies, thrips, leafminers, beetles, caterpillars, scales and spider mites (Table 2). One benefit of pesticide use is there is still an array of broad-spectrum insecticides that can “control” numerous pests with one application. In addition to the physical or aesthetic damage these arthropod pests cause, several insect pests that feed on ornamental plants are vectors of destructive plant pathogens, especially the phloem and mesophyll and epidermal cell feeders.

The array of feeding behaviors of the arthropod pests listed in Table 2 demonstrates the diversity of potential arthropod pest problems associated with producing ornamental plants. For example, in the hydroponic production of cut Transvaal daisy (Gerbera jamesonii), plants can be fed upon and damaged by a multitude of arthropod pests simultaneously including thrips and mites, leafmining flies, chewing caterpillars, phloem-feeding aphids and whiteflies, along with xylem-feeding lygus bugs.

Overall, no single pest management strategy will effectively solve every arthropod pest problem, so other pest management strategies must be implemented or considered in conjunction with the use of pesticides, including cultural (proper irrigation and fertility), sanitation (removal of weeds and debris), exclusion (installing micro-screening over greenhouse openings such as vents and sidewalls), and biological (releasing parasitoids and predators).

Although these strategies are important in minimizing arthropod pest problems, they do not provide the same level of regulation or protection as pesticides.

Future Prospects

Pesticide use will continue to be a significant strategy in dealing with arthropod pest populations so greenhouse producers can stay competitive in their markets. The benefit of pesticides as it relates to the production of greenhouse-grown crops is seldom emphasized or brought to the attention of the end-users. The end user–the consumer–benefits visually, psychologically and environmentally from the purchase and use of ornamental plants.

The development of traditional broad-spectrum pesticides has declined substantially within the last 10 years. But the advent and use of alternative or selective pesticides (insect growth regulators, insecticidal soaps, horticultural or petroleum-based oils, selective feeding blockers, beneficial fungi and bacteria, and micro-organisms) with favorable environmental and toxicological properties will continue to increase as long as they are affordable and effective against the diversity of arthropod pests encountered in greenhouse production systems.

Although these materials tend to be more selective, greenhouse producers can broaden the activity against the array of arthropod pests by tank mixing several materials together. In addition, many of these alternative pesticides appear to be compatible with certain natural enemies, which may augment currently existing pest management programs.

It should be noted from our experience, most growers are already using less-harmful pesticides. The use of pesticides may be the most feasible and cost-effective strategy to deal with arthropod pests in many greenhouse production systems. However, if federal and state regulations continue to restrict the use of pesticides, it will be more difficult for greenhouse producers to provide quality plant material that is actually “pest-free.” 

Leave a Reply

More From Insect Control...

April 28, 2016

Holistic, Integrated Approach To Pest Control Rooted In Research

Greenhouse growers have been practicing integrated pest management for decades, but it’s becoming increasingly more important with the continued scrutiny of conventional pest control by a number of “regulators” — government, retail, and consumers. I just returned from Meister Media Worldwide’s Biocontrols USA 2016 Conference, in Monterey, CA, at the beginning of March this year, which served 450 attendees and 50 exhibiting supplier companies. It’s clear from the presentations and the growing attendance at this specialized event — now only in its second year — that use of biocontrols in IPM will continue to be adopted widely, as more growers get past their personal hurdles of doubt and intimidation, and embrace a new way to approach pest and disease control. Many growers think of using biocontrols as an all-or-nothing approach, but ultimately, IPM is about balance. Growers will need to continue to focus on IPM, integrating chemistry with biology, because […]

Read More
Cicada (Greg Hoover, Penn State)

April 26, 2016

Cicadas Set To Emerge In Several Eastern States This Spring

While there’s no immediate cause for alarm, experts say the cicada’s egg-laying process can damage woody ornamentals and make them vulnerable to diseases.

Read More
Parasitized aphid mummies, ladybird beetle larvae

April 18, 2016

4 Things You Need To Know About Implementing Biological Controls

Biocontrols are useful alternatives to traditional pesticides that provide effective pest control in the greenhouse. Here are four ways to get started successfully.

Read More
Latest Stories

April 28, 2016

Holistic, Integrated Approach To Pest Control Rooted In…

Greenhouse growers have been practicing integrated pest management for decades, but it’s becoming increasingly more important with the continued scrutiny of conventional pest control by a number of “regulators” — government, retail, and consumers. I just returned from Meister Media Worldwide’s Biocontrols USA 2016 Conference, in Monterey, CA, at the beginning of March this year, which served 450 attendees and 50 exhibiting supplier companies. It’s clear from the presentations and the growing attendance at this specialized event — now only in its second year — that use of biocontrols in IPM will continue to be adopted widely, as more growers get past their personal hurdles of doubt and intimidation, and embrace a new way to approach pest and disease control. Many growers think of using biocontrols as an all-or-nothing approach, but ultimately, IPM is about balance. Growers will need to continue to focus on IPM, integrating chemistry with biology, because […]

Read More
Cicada (Greg Hoover, Penn State)

April 26, 2016

Cicadas Set To Emerge In Several Eastern States This Sp…

While there’s no immediate cause for alarm, experts say the cicada’s egg-laying process can damage woody ornamentals and make them vulnerable to diseases.

Read More
Parasitized aphid mummies, ladybird beetle larvae

April 18, 2016

4 Things You Need To Know About Implementing Biological…

Biocontrols are useful alternatives to traditional pesticides that provide effective pest control in the greenhouse. Here are four ways to get started successfully.

Read More

March 22, 2016

EPA Approves Syngenta’s Mainspring GNL Insecticide For …

Featuring the active ingredient cyantraniliprole, Mainspring GNL provides broad-spectrum control of key pests, such as thrips, whiteflies, aphids, caterpillars, leafminers, and leaf-feeding beetles.

Read More
Biocontrols and beneficials absolutely can be used in outdoor production, with the use of banker plant systems

March 8, 2016

France-Based InVivo Acquiring Bioline, Syngenta’s Bioco…

Bioline, a subsidiary of Syngenta, specializes in the production and marketing of biological control agents, and in particular macroorganisms active against insect pests in fruits, vegetables, and flowers.

Read More

February 17, 2016

Why It’s Important To Stay One Step Ahead Of Thri…

Keep thrips populations in check and avoid pesticide resistance by using spray and drench products known for their effectiveness.

Read More
The beneficial parasitoid Encarsia formosa feeding on greenhouse whitefly

February 12, 2016

Biological Pest Control Starts With Accounting For Pe…

When pest pressure is high, biological controls alone may not be enough to take care of the problem. Make sure that any pesticides you use won’t harm the beneficials hard at work in your greenhouse.

Read More
Suzanne Wainwright-Evans

February 8, 2016

Register Now For Biocontrols USA 2016 Workshop

Biocontrol is becoming a mainstream part of growing plants commercially. Every good program starts with quality products and a good supply chain. Register now to join us from 1:00-4:00 p.m. on March 4, following the conclusion of the education program at the Biocontrols USA 2016 Conference & Expo in Monterey, CA for a special event that will help you improve your biocontrols program. In this informative, real-world workshop led by biocontrols expert Suzanne Wainwright-Evans, owner of Buglady Consulting, you’ll learn: The key players that are producing beneficials How to check product quality once you get them The latest trends and practices growers are using to implement beneficials into their programs Important pitfalls to avoid. A roundup of the current biocontrol research that can help you be more successful in your production practices this season. Wainwright-Evans, a pest management specialist, has been involved in the green industry for more than two […]

Read More

January 12, 2016

EPA Releases Preliminary Risk Assessment For Imidaclopr…

The assessment, which will soon be open for public comment, indicates that imidacloprid potentially poses risk to hives when the pesticide comes in contact with certain crops that attract pollinators.

Read More
Vestaron

December 30, 2015

Vestaron’s Spear Bioinsecticide No Longer Carries Bee T…

Following a review that shows it has no detrimental effect on honeybees, EPA has removed the bee toxicity warning statement from Spear.

Read More
USDA Whistleblower Case

November 3, 2015

USDA Bee Scientist Alleges He Was Punished For Reportin…

Entomologist Jonathan Lundgren has filed a whistleblower complaint alleging USDA retaliated against him because of his research on the adverse effects of neonicotinoid insecticides on bees and monarch butterflies.

Read More

October 7, 2015

Ball FloraPlant Eliminates Neonicotinoid Use On Its Off…

Ball FloraPlant has announced its offshore cuttings farms did not use neonicotinoid-based pest management chemicals during its spring crop production last shipping season, and will continue to be neonic free this year. Instead, the company and its greenhouse managers have relied on alternative means to supply insect-free cuttings to its global customer base.

Read More
Nemasys And Millenium Beneficial Nematodes from BASFm_Nematodes

October 7, 2015

How BASF’s UK Biological Production Facility Expa…

BASF has expanded its biologicals production facility in Littlehampton, UK. The new capacity increases the company’s ability to double the production of beneficial nematodes and inoculants.

Read More

September 23, 2015

New Crop Protection Products And Label Updates

Here are some of the most recent products released and label updates for crop protection agents in the greenhouse and nursery market. Fame Fungicides (FMC Corp.) FMC Corp. has introduce Fame fungicides, a family of FRAC 11 group (Strobilurin) products that delivers fast-acting, patented fluoxastrobin protection against major soil and foliar diseases. Rainfast in 15 minutes, Fame fungicides can be used on most greenhouse and nursery plants and provide fast foliar and root uptake. “Proven by university research, Fame fungicides offer fluoxastrobin action, which ensures a high degree of systemic activity to provide very rapid disease protection and stop further growth of established disease,” says Naimur Rahman, strategy and fungicide marketing product manager for FMC. The Fame fungicide family includes: • Fame SC: a suspension concentrate fungicide containing fluoxastrobin that controls major diseases, including anthracnose, downy mildew, powdery mildew, scab and leaf spot. It provides rapid foliar and root uptake […]

Read More
Offshore farm profiles Dummen Orange Las Mercedes Solanaceas GH

September 8, 2015

Dümmen Orange Implementing Consistent Standards On All …

Owning and operating several locations can be a challenge in maintaining consistent quality and cleanliness across the board. This is true of both breeders and growers. But those who do it right have invested in technology and practices that ensure that plant quality matches, no matter where their plants are shipped from. That’s the goal for Dümmen Orange. Now the world’s largest producer of unrooted cuttings, the company has a combined 150 hectares or 370 acres of production space worldwide, dedicated to cuttings production. Recent acquisitions of product portfolios, both this year and in the past few, has raised the company’s cuttings production expectation to more than 1.4 billion, including 350 million in North America. It has farms all over the world (see the 2015 Top Cuttings Producers ranking to see where), and produces cuttings for its own genetics, as well as collaborating with more than 30 third-party breeders across all […]

Read More
Bill Lewis grower manager at Delray Plants

August 31, 2015

Delray Plants Takes Preventative Approach To Pest Contr…

Trying to control pests effectively on a wide variety of crops is a major undertaking. Delray Plants in Venus, Fla., has been using biological controls as a part of its pest control program for more than 10 years. It operates 300 acres, which includes covered structures and 7 acres of outdoor field production.

Read More
Feature image The Aphid Guard Aphid Banker Plant, coming soon to the market, supports beneficial insect populations.

June 21, 2015

The Latest In Crop Protection

Protecting your plants from the latest threats is no easy task, but new product lines promise to safely and effectively eliminate a wide range of pests and diseases, without harming your employees or the environment.

Read More
Bee On Flower

June 18, 2015

Pest Management And Marketing Strategies For Bee-Friend…

Michigan State University Extension shares pest management practices to produce plants that are safe for pollinators and marketing strategies for clearing up confusion about bee-friendly plants.

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