Protecting crops — naturally

You know your greenhouse crop is ceaselessly under attack…but what’s the best response?

Diseases and insect infestations have always been major threats in agriculture. Damping off (seedling rot), root rot, stem rot ... plant-damaging pathologies like these are a constant menace to economically important crop species like vegetables grown via controlled environment greenhouse production.

The diseases can be caused by contaminated soil and soil-borne pathogens, including bacteria, parasitic water molds and the mycotoxins from anamorphic (form changing) fungi. Invasive pests include whiteflies, aphids, mealy bugs, and spider mites.

Common greenhouse weeds such as chickweed, creeping wood sorrel, bittercress and others can become infected with impatiens necrotic spot virus and tomato spotted wilt virus and act as disease sources. Weeds infested with sucking thrips can vector viruses onto susceptible greenhouse crops.

So what’s the best response for waging war against such invaders. First, you can fight the pathogens and pests chemically with synthetic pesticides, typically manufactured from petrochemical or inorganic raw materials. Pesticides protect plants from various weeds, nematodes (worms) and fungi and so can raise production yields. Tetraethyl dithiopyrophosphate (TEDP), for example, is a pesticide commonly used in greenhouses as a fumigative agent. EDP has applications as an insecticide, mitocide and acaricide (kills ticks and mites).

However, though not as deadly as DDT (which is banned in the U.S.), TEDP is still a highly toxic chemical compound. Today, strict regulations exist to control chemical pesticide use, and there is political pressure to remove the most hazardous chemicals from the market.

So, growers have incentives to balance chemicals with more benign biological control agents—“biologicals.” Bio-based pesticides are made up of renewable resources and contain no synthetic active ingredients. These bio-pesticides have a much more positive impact on the environment than their synthetic counterparts and are expected to be one of the fastest-growing pesticide segments in the near future.
 

Integrated pest management (IPM)

Going “biological” means reducing infestations from outside sources by incorporating non-chemical methods in an Integrated Pest Management (IPM) program. IPM, an environmentally sensitive approach to controlling pest damage to crops, emphasizes the growth of a healthy crop with the least possible disruption to agro-ecosystems while, in the process, encouraging natural pest control mechanisms.

Biological pest management, a key part of any effective IPM program, uses natural organisms to control pests. An example of biological pest control is the introduction of predatory insects like ladybugs into greenhouses. These “good” bugs battle “bad” bugs like aphids to keep greenhouse vegetable crops healthy.

Tim Madden is president of Biodynamics, an Akron, Ohio, specialist in Controlled Environment Agriculture (CEA) business solutions. An IPM advocate, Madden says that by augmenting (or even replacing) industry standard synthetic pest management with biological IPM, growers can significantly increase food safety and the quality of produce.

“Biological IPM not only helps prevent insect, fungi and pathogen contamination, but also eliminates the use of carcinogenic chemical pesticides, fungicides and herbicides that get absorbed through plant leaves, stems and roots at a cellular level,” says Madden. “These substances degrade plant nutritional value by destroying the beneficial microorganisms that help us metabolize and absorb vital nutrients essential to a healthy diet.”
 

Biologicals controls market

The global crop-protection industry is dominated by big agrochemical companies such as Syngenta, Monsanto and Bayer CropScience.

According to a Transparency Market Research report titled “Crop Protection Chemicals Market – Global Industry Size, Market Share, Trends, Analysis and Forecast, 2011–2018,” the global crop protection market was worth USD $48.0 billion in the year 2011. It is expected to reach USD $71.3 billion by 2018, growing at a CAGR of 5.4 percent from 2011 to 2018. Herbicides (weed killers) formed the largest category in the overall crop protection market, contributing about USD $19.9 billion for the year 2011.

The International Biocontrol Manufacturers’ Association (IBMA) puts the global crop-protection business at USD $44.0 billion. According to David Cary, IBMA executive director, while the biological-control market is just three percent (USD $1.3 billion) of total sales, it’s growing 10 percent per year.

Basel-based Syngenta is now breeding and selling fly-eating mites, caterpillar-killing wasps and “premium quality” bees in bulk to help farmers find chemical-free solutions to crop damage. Monsanto, the biggest developer of genetically modified crops, is engineering naturally occurring molecules to help kill weeds, insects and plant viruses.

Deal making in this business “has really escalated in the last 12 months,” says Cary. On July 6, 2013, Bayer CropScience paid $425 million for biological pest management solutions specialist AgraQuest (based in Davis, Calif., and founded by Dr. Pamela Marrone before she began Marrone Bio Innovations).

The biggest profits on the crop protection horizon may come from hybrid products that combine what nature has to offer with synthetic (but still toxic) insecticides produced in labs.

Synthetic pesticides are segmented as insecticides, herbicides and fungicides. Globally, the market is dominated by herbicides, which accounted for more than 40 percent of the total pesticide demand in 2011, according to “Crop Protection Chemicals Market by Types (Herbicides, Fungicides, Insecticides, Bio-pesticides and Adjuvants), by Crop Types, by Geography: Global Trends and Forecast to 2018,” an April 2013 report from MarketsandMarkets.com.

Some crop-killing pests are able to develop resistance to powerful chemicals with one generational mutation, according to William Dunham, managing partner of the biological-control market research firm Dunham Trimmer, based in Mendham, N.J.

“If you rotate bio-pesticides with traditional ones, you can prolong the life of the product,” Dunham says. Also, companies with pesticides whose patent is expiring may be able to add naturally occurring bacteria and launch an entirely new product eligible for a new patent.
 

Worth noting

Marrone Bio Innovations (MBI), based in Davis, Calif., is a provider of bio-based pest management and plant health products. MBI’s Regalia family of biofungicides, approved for both field and greenhouse applications, help trigger a plant’s natural defenses to control a broad spectrum of agronomically important fungal and bacterial diseases.

And MBI’s flagship bioinsecticide Grandevo^® is used as a microbial insecticide in greenhouse pest management applications.

“Bio-pesticides today are a viable partner with existing synthetic pesticide programs,” says Marrone Bio’s Rich Fedigan. “We’re in an age when biologicals should be considered as a key component in any grower’s pest management program.”

According to Fedigan, the efficacy of today’s biologicals can equal or exceed that of synthetic pesticides and bring to market a number of benefits such as grower safety, reentry safeguards for agricultural workers and post-harvest maximum residue levels that synthetics don’t offer.

“Biologicals provide a low risk of insects developing resistance, and when you work a biological agent into a synthetic pesticide management program, you reduce the use of the synthetics. Spraying less often reduces the pesticide load.”
 

Advanced Biological Marketing (ABM)

Advanced Biological Marketing (ABM), Van Wert, Ohio, develops, manufactures and distributes agricultural biological agents. ABM’s Induced Gene Expression Triggers Technology is formulated into several products that provide multifunctional and crop specific blends of beneficial strains of Trichoderma (culturable soil fungi) microbials.

“Growers need to know that there is currently a major revolution underway in our understanding and use of biological agents,” says Gary Harman, chief science officer for ABM “The recent advances in ‘-omic’ – proteomic, genomic – technologies, including of the microorganisms and the plant, together with modern genetic sequencing tools makes possible advances that we in the field only dreamed about even a few years ago.”

According to Harman, the best strains of biological agents confer long-term benefits. In contrast, if chemical pesticides are used, there is a short-term effect because the chemicals do not grow or increase in amount.

“The best biological agents, however, colonize roots and induce changes in gene expression that result in beneficial effects on plant physiology,” says Harman. “Depending on the strains used, and their interactions with plants, disease resistance may be conferred. And improved fertilizer usage may occur – allowing growers to use less fertilizer.”

Moreover, plant growth and especially root development may occur, and some strains induce rooting of cuttings, he noted. Increased resistance to drought and other stresses may also occur, while a side benefit for vegetable production may be improved antioxidant levels in produce.

But a word of caution from Dr. Harman: “While biological agents may increase plant health and vigor, they probably will not cure existing diseases,” he said. “If existing diseases are present, a chemical pesticide may be important.”
 

Novozymes

Charlie Hampton, Brookfield, Wis., is North American marketing manager for global biopesticide specialist Novozymes BioAg. Novozymes’ biocontrol products are based on microorganisms and naturally occurring fungi to provide control against insects, disease and weed pests.

“Biologicals bring these key benefits — proven safety to many beneficial insects, resistance management strategy and a rotational tool with synthetic pesticides,” says Hampton.

The most important technical challenge bio-based pest management and plant health products in controlled environments involves residual of biologicals – how long they last in controlling pests, explained Hampton.

Regarding business-related issues:

“Biological products need to perform similarly to synthetic pesticides – meaning similar efficacy,” he said. “If a producer/grower can see the same results with biologicals as they do with synthetic chemistry – that’s a win for biologicals while doing it more sustainably.”

Biological crop protection is an area within production agriculture that is seeing tremendous investment in discovery, noted Hampton.

“There will continue to be new products brought to market over the next several years that will provide quality control of pests with improved efficacy while doing so in a sustainable way.”

Ned Madden is a California-based Controlled Environment Agriculture (CEA) consultant, marketing professional and journalist who writes about urban agriculture technology and business-related topics.