Chewing Gum Will Lose Its Flavor Without Herbicide Use In Mint Fields

Weedy Mint Field (Foreground)

Weedy Mint Field (Foreground)

Peppermint and spearmint are grown in the U.S. commercially on close to 100,000 acres with peppermint comprising 70% of the acreage. Mint crops are grown to extract the oil produced in glands on the plant’s leaves. The U.S. produces about 9 million pounds of mint oil which is used to flavor chewing gum, toothpaste, pharmaceuticals and liqueurs. One drum of mint oil weighing 400 pounds can flavor more than 5 million sticks of chewing gum or 400,000 tubes of toothpaste. Mint crops are harvested mechanically and any weeds in the field are harvested along with the mint. If the weeds are processed along with the mint, the mint oil loses its flavor; as a result, mint growers use herbicides to prevent weeds from contaminating the mint oil with off-flavors.

“Mint oil yield is reduced when weeds compete with mint for light, nutrients, and water. Mint oil quality is reduced when weeds impart off-flavors and odors to mint oil during distillation.

The demand for mint oil is based on its desirable flavor and odor. Mint oil is used to flavor medicines, toothpaste, candy, and chewing gum. If mint oil is contaminated with undesirable flavors or odors then its quality is downgraded.

Unfortunately, many weeds harvested with mint hay impart off-flavors to mint oil during distillation. This results in a reduction of mint oil quality and price.

In one study, the oil from hay containing 5% pigweed was not marketable.

3.2 Horseweed plants per square yard would make the mint oil unmarketable.

Mint oil severely contaminated with objectionable weed odors is not marketable and is therefore valueless. Infestations of horseweed, pigweed, western goldenrod, common lambsquarters, and prickly lettuce at 7 or more plants per square yard are likely to make mint oil unmarketable.”

Author: Heap, I.
Affiliation: Dept. of Crop and Soil Science, Oregon State University.
Title: The Effect of Weeds on Mint Oil Yield and Quality. 1993.

Tight Market Standards For Sweet Corn Necessitate Insecticide Sprays

Bugs in corn

Worms in sweet corn

Consumer surveys show that the lack of insect damage is the most important factor when deciding which sweet corn to buy. Processors and stores require larval infestations to be < 5-10% of sweet corn ears. To meet those standards, sweet corn growers throughout the U.S. must use insecticides.

”Minnesota is the second largest producer of processing sweet corn, Zea mays L., in the United States with an annual production of >53,000 ha; the state also produces ≈4,000 ha for fresh market. The European corn borer, Ostrinia nubilalis (Hübner), and corn earworm, Helicoverpa zea (Boddie), continue to be the most important insect pests of sweet corn in the upper Midwest. To minimize economic risks associated with insect damage in sweet corn, most growers rely on insecticides to manage these pests.

Most processors and fresh market growers require larval infestations and brown kernel incidence to be <5-10% of harvested ears.”

”Sweet corn is the most commonly grown vegetable crop in Pennsylvania. Most is grown for fresh-market. Stringent control is required to meet market standards and most acreage (~80%) is sprayed to control corn earworm, fall armyworm, and European corn borer.”

Authors: O’Rourke, P. K., and W. D. Hutchison.
Affiliation: Department of Entomology, University of Minnesota.
Title: Binomial sequential sampling plans for late instars of European corn borer (Lepidoptera: Crambidae), corn earworm (Lepidoptera: Noctuidae), and damaged kernels in sweet corn ears.
Source: J. Econ. Entomol. 2004. 97[3]:1003-1008.

Author: Fleischer, S.
Affiliation: Department of Entomology, Penn State University.
Title: Regional patterns in corn borer and fall armyworm populations: implications for management.
Source: 58th New Jersey Agricultural Convention and Trade Show. 2013 Proceedings. February 5-7. Pgs. 118-119.

Insecticide Use is Critical to Successful Tomato Production

Insect Damage: Tomatoes

Insect Damage: Tomatoes

Insecticides are generally used on close to 100% of tomatoes grown in eastern states to prevent damage from a large number of species that would feed directly on the tomatoes- significantly lowering their value. A study of tomatoes in Virginia revealed that uncontrolled insects lowered marketable yield by 33%. Insecticide cost ($230/A) prevented losses of from $3000-$7000/A.

“Insect pest management is critical to successful tomato production in the Mid-Atlantic U.S. Important pests each year often include the tomato fruitworm (= corn earworm), thrips, stink bugs, aphids, and spider mites.  Occasional pests also include armyworms, Colorado potato beetle, hornworms, cabbage looper, and leafminers. To control this complex of pests, insecticide usage is often intense on commercial farms. For instance, in Virginia, tomato growers make an average of 7 to 10 pesticide applications per crop.

Although IPM and biological control programs have been demonstrated, insecticides continue to be the chief management tool by which damaging insect pests can be controlled immediately and economically for conventional tomato producers. Because strict quality standards for produce coupled with high production costs are unlikely to change significantly, current and future tomato pest management strategies are likely to include an insecticide component.”

Author: Thomas P. Kuhar
Affiliation: Associate Professor – Vegetable Entomology, Virginia Tech
Title: Update on insect pest management for tomatoes
Source: 2011 Proceedings 56th New Jersey Annual Vegetable Meeting. January 11-13, 2011. Available at:

Downy mildew of Basil is here to Stay

Downy Mildew Close-up

Downy Mildew Close-up

Downy Mildew Spore Growth on Basil Leaves

Downy Mildew Spore Growth on Basil Leaves

Downy mildew of basil is a new destructive disease that appears to be here to stay. In the first years of its appearance in the U.S., complete crop losses occurred for some growers because basil leaves with any mildew are unmarketable. Applying fungicides frequently and starting before first symptoms are considered necessary to control basil downy mildew effectively.

“Sweet basil (Ocimum basilicum L., Fam. Lamaiaceae) is the most commercially important annual culinary herb crop grown in the United States. Sweet basil is grown for culinary use for both fresh and dry consumption and as a source of essential oil and oleoresin for manufacturing perfumes, food flavors, and aromatherapy products.

Basil downy mildew… is a new disease of basil in the United States. …In the United States, the pathogen was first discovered in Florida in the fall of 2007. Since that time, basil downy mildew has been found throughout the eastern United States and in regions of commercial basil production in the Midwest and California.

Once basil plants become infected and develop symptoms, they are no longer marketable as a fresh product. …Currently, there is no known resistance or tolerance to basil downy mildew leaving 100% of the sweet basil acreage in the eastern United States vulnerable to the pathogen. Without adequate chemical control options and genetic resistance, basil downy mildew has the potential to destroy basil production in the eastern United States and in all other areas where basil is being produced.

Selection criteria such as foliar morphology, plant architecture as well as the presence of secondary metabolites and other factors that provide a less favorable microenvironment to the pathogen need to be examined as potential avenues for developing downy mildew-resistant sweet basil cultivars. Until this can be achieved, basil growers will have to rely on multiple applications of the few commercial fungicides currently registered to produce a marketable crop. Additionally, for organic basil growers, control of basil downy mildew will be even more challenging because there are fewer approved products labeled for organic use.”

Authors: Wyenandt, C. A., et al.
Affiliation: Department of Plant Biology and Pathology, Rutgers University
Title: Susceptibility of basil cultivars and breeding lines to downy mildew (Peronospora belbahrii)
Source: HortScience. 2010. 45(9):1416-1419.

California Alfalfa Production Would be One Million Tons Lower with Conversion to Organic Practices

Alfalfa Weevil on Damaged Leaf

Alfalfa Weevil on Damaged Leaf

California is the #1 dairy state in the U.S. and one million acres of alfalfa are grown in the state. Alfalfa growers use herbicides to control weeds and insecticides to control key pests-the Egyptian and alfalfa weevils. Organic alfalfa growers do not have effective methods of controlling weeds and insect pests and they incur yield losses – particularly by harvesting early to avoid damage. A recent economic analysis from the University of California estimated that organic production of alfalfa is one ton less per acre which would mean a loss of one million tons of alfalfa if the entire state converted to organic practices.

“The Egyptian and alfalfa weevils are the most serious pests of alfalfa, causing yield and quality losses to the first harvest in late winter/early spring.

Most organic growers rely on early harvest to minimize weevil damage, but yields will be reduced.

The risks associated with the production of organic alfalfa hay should not be minimized. Weather and other risks are a continual concern for conventional growers, but organic growers face additional risks such as pest outbreaks that cannot be adequately controlled with organic methods.

Average annual yields in California range from 5.0 to 10 tons per acre with three to ten cuttings depending on location and alfalfa variety. Eight tons per acre over seven cuttings per year is common in the Central Valley. The crop in this study is assumed to yield 7.0 tons of hay per acre because yields of organic alfalfa are often slightly lower than conventional due to only partial control of many pests and weeds and the difficulty meeting the nutritional needs of alfalfa using solely organic sources.”

Authors: Rachael F. Long, et al.
Affiliation: US Cooperative Extension Farm Advisor, Yolo, Solano & Sacramento Counties
Title: Sample costs to establish and produce organic alfalfa hay California 2013
Source: University of California Cooperative Extension. 2013.

California Avocado Production Would be 82 million Pounds Lower with Conversion to Organic Practices

New Orchard Weeds

New Orchard Weeds

California farmers produce 550 million pounds of avocados annually. 8% of the avocado acres are managed with organic production practices. A recent economic analysis by the University of California shows why so few avocado acres are organic. Even though organic avocados receive a price premium, lower yields (15% lower) means lower profits than avocados grown with chemical inputs. The 15% lower yields would mean a loss of 82 million pounds of avocados if all the California avocado growers switched to organic practices. Weeds are the biggest problem for organic avocado growers.

“Profitability estimate of organic avocados in these counties is lower than avocados produced conventionally. Though organic avocados are considered to receive $0.20 more per pound than conventional avocados, organic avocado production shows lower yield than the conventional production.

Based on our discussions with growers and the UCCE farm advisor, organic yield is considered lower than the conventional production. In this study, organic avocado yield is estimated at 15% lower than the conventional yield.”

Author: Etaferahu Takele, et al.
Affiliation: Area Farm Advisor, Agricultural Economics/Farm Management, University of California Cooperative Extension (UCCE) Southern California
Title: Avocado sample establishment and production costs and profitability analysis san diego and riverside counties, 2011 organic production practices
Source: University of California Cooperative Extension. 2013.

It Never Rains in Southern California, But When It Does, Fungicides are Essential

Gray Mold

Gray Mold

Most of the table grape production in the U.S. is located in the San Joaquin Valley. Rainfall at harvest is uncommon. However, when it does rain, gray mold can reach epidemic proportions if fungicides are not used. Gray mold is caused by a fungus that is activated by rainfall. The fungus produces a short tube with a suction cup and a peg that forces its way through the grape cuticle. Inside the grape, the fungus grows and exudes enzymes that degrade the fruit. Cracks form in the grapes and spores are produced that spread gray mold to other grape clusters. Even a single infected fruit within a table grape package can cause severe losses.

“Timing of fungicide applications to control gray mold is primarily driven in vineyard environments by the occurrence of rainfall. Rainfall at harvest, an uncommon event in the San Joaquin Valley of California, causes abundant production of inoculum and epiphytotics of the disease in vineyards, and fungicide applications are critically needed when this rare event occurs. This area, where most of the table grape production in the United States is located, is typically rainless throughout these periods and B. cinerea seldom causes significant vineyard bunch rot, but it routinely causes substantial postharvest decay if measures to control it are not taken.”

Authors: J.L. Smilanick, et al.
Affiliation: USDA ARS
Title: Control of postharvest gray mold of table grapes in the san Joaquin valley of California by fungicides applied during the growing season
Source: Plant Disease. 94[2]:250-257. 2010.

Herbicide Use in Finland has Increased Significantly to Protect the North Sea

Herbicide sales: Finland

Herbicide sales: Finland

In 2001, herbicide use began to increase in Finland largely due to government policies subsidizing growers to no longer plow fields for weed control. Finland is a signatory to the North Sea Treaty which includes a goal of reducing nutrients into the North Sea by half. Research showed that a considerable amount of phosphorus moves into waterways with eroded soils from fields that are plowed in the autumn. Thus, growers now are using herbicides to control weeds without plowing in order to keep phosphorus out of the North Sea.

“Our weed survey represented part of a follow-up project on the impacts of agri-environment policy in Finland. For instance, reduced tillage has been one of the subsidized measures primarily implemented to reduce nutrient leaching. Spring cereals, 1.1 million hectares in total, covering 50-55% of arable land, dominate crop production in Finland. In the 1990s ploughing was still the standard tillage practice in spring cereal fields, while the latest statistics show that only approximately half of the cultivated cereal field area is currently ploughed. Ploughing has been replaced with reduced tillage methods (29%) or direct drilling (17%). At the same time, the sales of glyphosate have more than doubled within a decade in Finland.

Increased use of glyphosate in Finland is notable; in 1999, the annual sales of glyphosate products were sufficient to treat about 13% of arable land under cultivation or fallow, while the same figure had increased to 37% in 2010.”

Author(s): Salonen, J., et al.
Affiliation: MTT Agrifood Research Finland, Plant Production Research, Jokionen, Finland
Title: Impact of changed cropping practices on weed occurrence in spring cereals in Finland – a comparison of surveys in 1997-1999 and 2007-2009.
Source: Weed Research. 53:110-120. 2012.

Global Warming Likely to Result in Increased Insecticide Sprays in the Northeast

# of Insecticide Sprays for Sweet Corn (Today)

# of Insecticide Sprays for Sweet Corn (Today)

The U.S. is likely to warm substantially over the next 40 years. Along the eastern seaboard, average temperatures will increase in a northward direction. Future temperatures in New York State will be similar to current temperatures in the Carolinas. Increased temperatures and earlier onset of the growing season will reduce the winter mortality of insects, increase the rate of insect growth and increase the number of generations during the crop season. In response, insecticide applications are likely to increase in the northeast-a point recently made in a major climate change report from USDA.

“A warming trend is likely to lead to increased pesticide use in the Northeast due to earlier arrival of migratory insects, higher winter-time survival of insects that currently are only marginally adapted to the region, and more generations of insects within a single season.

With more pests shifting northward, generation times decreasing, and abundances increasing in the future, management costs are expected to increase due to more frequent application of pesticides. For example, pesticide applications to control lepidopteran pests (e.g., moths) on sweet corn decrease with increase in latitude from 15 to 32 times per year in Florida, four to eight times per year in Delaware, and zero to five times per year in New York. “

Author(s): Walthall, C.L., et al.
Affiliation: USDA
Title: Climate change and agriculture in the United States: effects and adaptation
Source: USDA, February 2013. Available at:

Southern California Vineyards Recover Thanks to Insecticide Applications

Grapevines Destroyed in 1999

Grapevines Destroyed in 1999

Temecula Today

Temecula Today

In 1999, about one-third of the vineyards in Temecula Valley, Riverside County, California were destroyed due to Pierce’s Disease which is caused by a bacteria transmitted to grapevines by an insect-the glassy winged sharpshooter. The disease seemed destined to spread throughout Southern California. However, research demonstrated that a carefully-timed insecticide application would prevent the sharpshooter from transmitting the disease to grapevines. As a result of this insecticide use, the wine grape industry in Southern California has recovered and is prospering.

“Twelve years ago a Pierce’s disease epidemic in Southern California wine grapes prompted a multi-pronged local, state and federal attack to contain the disease spread and find a cure or treatment.

Riverside County agriculture officials declared a local emergency in 1999 and 300 acres of Temecula wine grape vines were destroyed after they were found to be infested with the glassy winged sharpshooter.

Emergencies were declared, a task force was formed, and in 2000 $22.3 million in federal financial assistance was secured to reduce pest infestations and support research.

Research found that the Southern California epidemics were almost entirely the result of vine-to-vine transmission…. A protocol of applying one carefully timed application of a persistent systemic insecticide such as imidacloprid virtually eliminates the vine-to-vine spread.

Ben Drake is a Temecula-area wine grape grower and vineyard manager who began seeing problems from PD in the Temecula Valley as early as 1997.

We’ve found that if we apply (imidacloprid) at the middle to the end of May, before the sharpshooter moves out of the citrus and goes into the vineyards, we get levels of the material into the plant high enough that when the sharpshooter flies over from the citrus groves to try it, they just fly back where they came from. Or, if they feed long enough, it will kill them.

But just look at the Temecula Valley now to understand what’s changed: From 12 wineries in 1999, the Temecula Valley Winegrowers Association website today lists more than 50 growers and 34 wineries…. A thriving agritourism industry has developed…. Existing wineries are expanding and new ones are under construction or in planning phases.”

Author: Christine Thompson
Affiliation: Reporter
Title: Grape growers urged to remain vigilant against sharpshooter pest
Source: Western Farm Press. 2011-12-12. Available at: