Potato Farmers in Ecuador Depend on Fungicides

Potato leaves with late blight; Fungicide treatment on right

Potato leaves with late blight (L); Fungicide treatment (R)

Carchi is the most important potato-growing zone in Ecuador. Smallholder households dominate production and they sell the vast majority of output. The biggest biological constraint to potato production in Ecuador is the disease late blight caused by the fungus p. infestans. The fungus can infect all the potato plants in a field in three days and losses can be as high as 100%. A survey of smallholder potato farmers in Carchi showed how dependent they are on fungicides.

“Even though potatoes have been one of the main crops in the Andes for thousands of years, under present production and market conditions the farmers in Carchi cannot produce potatoes without pesticides, particularly fungicides against late blight (caused by Phytophthora infestans) and insecticides to control the Andean weevil (Premnotrypes vorax). Every one of the farmers in the area covered by our project in the province of Carchi used fungicides. On average, they treated 6.7 times with 2.6 products at each treatment. They generally applied fungicides up to eight times during each production cycle, making fungicides the most frequently applied type of product.”

Authors: Sherwood, S. G., et al.
Affiliation: Integrated Pest Management Project, International Potato Center (CIP),
Title: Reduction of risks associated with fungicides: technically easy, socially complex.
Source: 2002. Reduction of Risks Associated with Fungicides: Technically Easy, Socially Complex. pp. 93–109. In: Fernández-Northcote E.N. (ed), Memorias del taller internacional Complementando la resistencia al tizón (Phytophthora infestans) en los Andes, Febrero 13–16, 2001, Cochabamba, Bolivia, GILB, Taller Latinoamérica 1. Centro Internacional de la Papa, Lima, Perú. Available online: http://www.share4dev.info/kb/output_view.asp?outputID=3480

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Without Insecticide Sprays, European Olive Oil Would Smell and Taste Really Bad

Decay and feeding damage from olive fly

Decay and feeding damage from olive fly

More than 95% of the world’s production of olive oil (about 870 million gallons) comes from the Mediterranean region. The olive fly is an ancient pest mentioned in Greek and Roman writings dating back to the 3rd Century B.C. In heavily infested orchards more than 90% of the olives may be attacked. The larvae consume pulp which results in a reduction of oil quantity by 20-25%; the quality of the oil is also lowered. Oil obtained from olives infested with the olive fruit fly has 50-60% higher acidity. Exit holes made by larvae allow for the development of bacteria and fungi. Acidity is increased by fermentation through the action of bacteria and fungi and oxygen exposure. The larval gut contents may have an effect on the flavor of the oil and lead to a so-called “wormy smell”. In the 1960s, the availability of inexpensive chemical insecticides made it possible to protect the olive crop efficiently from the olive fly. Several countries such as Spain and Greece have government-sponsored programs that provide area-wide spray programs.

“The olive fruit fly, is considered to be the key pest of the Mediterranean Basin olive orchards. Females lay their eggs in both green and ripening olive fruit, and larvae feed upon the pulp of the fruit. They finally pupate inside the olive or exit to pupate on the ground. This pest causes a reduction in yield owing to a premature fruit drop or a loss of weight of the fruit caused by feeding larvae. Furthermore, microorganism growth inside the fruit increases the acidity of olive oils, which decreases their quality and commercial value. In table olives, B. oleae’s damage totally reduces their commercial value. Control methods against this pest include bait sprays, cover sprays and mass trapping. Traditional insecticides, such as organophosphates, and other more recently developed compounds, such as spinosad, are commonly applied as bait sprays.” 

Authors: Bengochea, P., et al.
Affiliation: Universidad Politecnica de Madrid, Spain.
Title: Insect growth regulators as potential insecticides to control olive fruit fly (Bactrocera oleae Rossi): insect toxicity bioassays and molecular docking approach.
Source: Pest Management Science. 2013. 69:27-34.

Small Apple Growers in Italy’s Trentino Region Benefit Greatly from Insecticide Use

Trentino Region

Trentino Region

The province of Trento, or Trentino, is a mountainous region and an important producer of apples with annual production of about 450,000 tons accounting for about 20% of Italian production. Apple farming is the main source of income for about 10,000 families in Trentino. In addition, another 6000 families depend on income from the apple sector for packing, transportation and other secondary activities. In 1989, the Public Administration of Trento approved a program for Integrated Production standards. Since 1991, Integrated Fruit Production (IFP) guidelines have covered all aspects of production. The apple crop in Trentino is almost completely managed by IFP standards. In Trentino, codling moth has two generations per year. The most common situation includes an application of an insect growth regulator at the first egg-laying period and two more treatments using insecticides with a different mode of action. In Trentino, uncontrolled codling moth would damage 50-90% of the apples. Apple production in Trentino remains generally quite profitable and provides a major contribution to the economic and social standards of the province. By preventing damage from insects and pathogens, pesticides play an essential role in the economic and social well-being of the region.

“Codling moth (CM), Cydia pomonella L., is a key pest affecting pome fruit worldwide. In the Trento province (northern Italy) control of this pest is achieved by integrated pest management (IPM) programmes, largely relying on insect growth regulators (IGRs) during the first generation and on curative pesticides timed according to the injury threshold level during the second generation. In large apple orchards, mating disruption is preferred and is normally combined with one insecticide application during post-flowering to control lepidopteran larvae in general, including leafrollers. Because of their efficacy against both overwintering leafroller larvae and CM eggs, IGRs are widely used.”

Authors: Ioriatti, C., et al.
Affiliation: IASMA Research Center, Italy.
Title: Early detection of resistance to tebufenozide in field populations of Cydia pomonella L.: methods and mechanisms.
Source: Journal of Applied Entomology. 2007. 131[7]:453-459.

The Insect that Started it all: The Colorado Potato Beetle

Spraying in Paris Green; Colorado Potato Beetle

Spraying Paris Green                        Colorado Potato Beetle

The Colorado Potato Beetle (CPB) is native to Mexico where it fed on a weed, buffalo bur. In 1859, the CPB had adapted to feeding on potato plants in the US and the results were devastating. Yields were reduced, potato prices quadrupled, and many farmers abandoned the crop. Paris Green, a paint pigment, was supposedly determined to have insecticidal properties by a farmer, who after painting his shutters, threw the remaining paint on potato plants infested with CPB. In 1872, entomologists at the USDA recommended that farmers use Paris Green to control CPB and by 1875, spraying Paris Green had become a universal practice in Midwestern potato fields.

“The first major Colorado potato beetle outbreak occurred in 1859 on potato fields about 100 miles west of Omaha, Nebraska. The subsequent expansion in beetle geographic range was somewhat mind-boggling, with beetles reaching the Atlantic coast of the U.S. and Canada before 1880. The first European population was established in France in 1922. By the end of the 20th century, the pest had become a problem all over Europe, in Asia Minor, Iran, Central Asia, and western China. Its current range covers about 16 million km2 on two continents and continues to expand.

Currently, the Colorado potato beetle is widely regarded as the most important insect defoliator of potatoes. One beetle consumes approximately 40 cm2 of potato leaves during the larval stage, and close to an additional 10 cm2 of foliage per day as an adult. In addition to impressive feeding rates, the Colorado potato beetle is also characterized by high fecundity, with one female laying 300–800 eggs. If left uncontrolled, the beetles can completely destroy potato crops.

The Colorado potato beetle has been credited with being largely responsible for creating the modern insecticide industry. Since 1864, hundreds of compounds were tested against this pest, and application equipment was specifically invented to aid their delivery.

Currently, insecticides still remain the foundation of the Colorado potato beetle control on commercial potato farms.”

Authors: Alyokhin, A., et al.
Affiliation: School of Biology and Ecology, University of Maine.
Title: Colorado potato beetle resistance to insecticides
Source: American Journal of Potato Research. 2008. 85:395-413.

In Greece, Spraying Mosquitos Makes Life Bearable

mosqueto

Mosquito Biting Human

Greece has a long history of mosquito-borne diseases (malaria, dengue fever) and there is scientific evidence that some inhabitants have contracted West Nile virus. Especially in Northern Greece where the majority of wetlands and rice fields are located, inhabitants and visitors suffer from an unbearable mosquito nuisance every year for more than 5 months (May – September) and counts of 150-200 mosquito bites per 15 minutes are not unusual. A large-scale mosquito insecticide spray program makes life bearable.

“Wide area mosquito control projects involve survey and applications in natural, agricultural, periurban and urban environment.

A total of about 8,000 sampling stations are established every summer period and checked weekly for larval activity. In addition more than 25,000 private properties (houses and tourist installations) are visited and checked for breeding sites.

The main spraying applications (larviciding) are conducted by four Hiller UE-12E helicopter, and an Ultra Light Motorized (ULM) aircraft. Minor applications are conducted by 15 conventional spraying units, mounted on 4×4 trucks and one low volume fan sprayer unit mounted on a Unimog 4×4 vehicle. For various spot treatments mainly in urban and periurban environment, knapsack sprayers and granule applicators were used.

In total a mean of 100,000 ha are sprayed with larvicides every year. About 80% of this surface is aerially treated. Spraying frequency of rice fields varies considerably from one to five times while this of the natural systems rarely exceeds two times per season.

The positive results of the project are clearly reflected in surveys in the form of questionnaires the company has conducted in 1999 and 2006 in a sample of 1000 inhabitants in 15 communities of the Thessaloniki plain: In 1999 100% of the people considered the mosquito problem unbearable before the beginning of the control project, while 68% considered it medium, small or non-existent after its implementation. In 2006 the results were 48% and 84% respectively.”

Authors: Iatrou, G. and S. Mourelatos.
Affiliation: Ecodevelopment S.A.
Title: Mosquito control in Greece.
Source: International Pest Control. 2007. May/June:66-69.

No Apple Maggots in Northwest Orchards Thanks to Spraying Outside the Orchards

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Apple Maggots

Apple maggot is a native pest of the eastern United States and Canada. In 1979 it was discovered in Oregon and has since moved into California, Washington, and other Western states. Female apple maggot adults deposit eggs singly under the apple skin. Damage is caused when larvae burrow and feed on apple flesh. Browning of the trails occurs as the apple responds to this injury and bacteria associated with maggots cause fruits to rot internally. No Western commercial apples have been infested with maggots thanks to spraying trees outside the orchards to keep them away.

“The first detection of this species [apple maggot] infesting apples in western North America occurred in the United States in Oregon in 1979; flies were caught in neighboring Washington the following year. However, no commercial apples from central Washington, the major apple growing region in the United States, have been found to be infested by R. pomonella, even though adults were first detected within this region in 1995.  

In Washington, an R. pomonella quarantine is established in 22 counties, including two under partial quarantine.

R. pomonella is widespread and abundant in Washington west of the Cascade Mountain range, but is much less abundant in central and eastern Washington except in Spokane County. It occurs in low numbers on the margins of the apple-growing regions in central Washington in native hawthorns and in even lower numbers in unmanaged roadside and backyard apples.

…In the major apple-producing regions of the Pacific Northwest of the United States, control does not occur at the orchard level but rather outside orchards. There is zero tolerance for infested apples. The probability of R. pomonella being moved in apples from Washington to Canada or Mexico is minimized by an extensive annual fly detection and insecticide spray response program conducted by the WSDA and cooperating county pest control boards. …Similar programs exist in Oregon, Idaho, and California.”

Authors: Yee, W. L., et al.
Affiliation: Agricultural Research Service, United States Department of Agriculture
Title: Status of Rhagoletis (Diptera: Tephritidae) Pests in the NAPPO Countries.
Source: J. Econ. Entomol. 2014. 107[1]:11-28.

Insecticides Defend Florida Avocado Trees from Invasive Species

14

The redbay ambrosia beetle is an invasive species that vectors a fungus, Raffaelea lauricola, that causes laurel wilt, a lethal disease of several plant species within the Lauraceae, including avocado… The spread of the fungus has affected large areas of native Lauraceae trees in the southeastern United States and is now threatening the avocado industry in south Florida.

“In February 2012, the first avocado tree in a commercial grove located in the northeastern quadrant of the avocado growing area was diagnosed with R. lauricola. As of July 2013, 90 trees have been diagnosed R. lauricola positive, and >1,900 symptomatic trees have been removed as part of a suppression and sanitation strategy. …Because of the lack of alternative pest management strategies (e.g. biological control, repellants, etc.), private landowners and avocado producers rely on applications of chemical insecticides to complement sanitation practices and protect trees in groves affected by this beetle-disease complex.

The current strategy is based in early detection and removal of diseased trees to eliminate beetle breeding sites and fungal inoculum sources. The diseased trees are uprooted, the stump and roots burned, the trunk and limbs are chipped, and the chips and adjacent trees are sprayed with insecticides.”

Authors: Carrillo, D., et al.
Affiliation: Tropical Research and Education Center, University of Florida.
Title: Potential of Contact Insecticides to Control Xyleborus glabratus (Coleoptera: Curculionidae), a Vector of Laurel Wilt Disease in Avocados
Source: Journal of Economic Entomology. 2013. December.

Insecticides Manage New Threat to Traditional St Patrick’s Day Meal

Bagrada Bugs

Bagrada Bugs

Every year around St Patrick’s Day, cabbage becomes a hit again thanks to the traditional meal of corned beef and cabbage. There is typically a 50 to 75% increase in demand for green cabbage beginning about two weeks before the March 17 holiday. California leads the nation in cabbage production accounting for about 24% of total U.S. production. Most of the cabbage from California at this time of the year comes from the state’s southern coast and southwestern desert. In 2010, a new pest of cabbage, the Bagrada bug, made its grand entrance into these desert cabbage fields and threatened the availability of cabbage for St Patrick’s Day.

“2010 was a year that many winter cole crop vegetable growers in the Desert Southwest would rather forget, thanks to the bagrada bug which attacked plant seedlings en masse.

Since then, research conducted at the University of Arizona and the University of California has led to a better understanding of the pest, its biology, and has helped reduce yield and income losses for growers.

When the bagrada bug made its 2010 grand entrance, winter vegetable growers, pest control advisers, and entomologists were stunned.

“The pest caught us blind. Suddenly the bagrada bug was everywhere in the desert,” says John Palumbo, University of Arizona (UA) Extension specialist and entomologist based at the Yuma Agricultural Center.

The pest attacks the underside of leaves during the day, and hides at night in the soil and under dirt clods.

The bagrada bug can quickly destroy a seedling. In Palumbo’s trials, a single insect placed on a cotyledon killed the plant in about 60 hours under laboratory conditions.

In another lab test, small pots were lined up in a row, each containing one of 12 different vegetable seedlings. The bagrada passed right by the head lettuce to feast on cole crops. Its feeding favorites include green cabbage, red cabbage, and radish.

If the plant lives, the damaged plant develops multiple unmarketable small heads instead of a single large marketable head or floret.

First found in South Africa, the insect arrived in the western hemisphere in the U.S. in 2008 in California; possibly as a stow-a-way on a cargo ship arriving at the Port of Long Beach. The insect then scurried into neighboring Orange County and kept moving.

Palumbo has conducted several trials with synthetic insecticides and natural predators. While he said bio-control is a ways off, pyrethroid insecticides currently provide the most effective control.

“Newer pyrethroids on the market appear to be more consistent with good knockdown and residual control.”

Residual activity usually lasts about five days.

Looking to the future, Palumbo says the best insecticidal control of bagrada may lie in neonicotinoid seed treatments, based on trial findings.”

Author: Blake, C.
Affiliation: Reporter
Title: Researchers making strides against bagrada bug
Source: Western Farm Press. 2013-11-20. Available at: http://westernfarmpress.com/vegetables/researchers-making-strides-against-bagrada-bug

Cowpea, A Major Source of Protein in Africa, Requires Insecticide Applications.

Nematodes!

Cowpea Damage From Insects

Cowpea (also known as black-eyed pea) originated in Africa and is the major source of plant proteins in the diet of rural populations in sub-Saharan Africa. Insect pests pose the greatest threat to cowpea production. The crop is attacked at every stage of its growth by insects. Since the late 1970s, extensive studies on insect pests of cowpeas have been conducted at the International Institute of Tropical Agriculture (IITA). IITA’s Guide to Cowpea Production in West Africa states that generally, 2-3 sprays are required for a good crop of cowpea.

“Cowpea is one of the most important food and forage legumes in the semi-arid tropics.

Despite cowpea’s importance and high yield potential in the Nigerian savannas, insect pest attack is a major constraint upon production. Severity can vary, and sometimes lead to total yield loss.

High levels of insect resistance are not available in current cultivars.

Insecticide application is the most widely known means of a pest control method in cowpea; it is not otherwise feasible to grow cowpea commercially. Farmers can improve yield 10-fold if insecticides are used.”

Authors: Kamara, A. Y., et al.
Affiliation: International Institute of Tropical Agriculture, Nigeria.
Title: Integrating planting date with insecticide spraying regimes to manage insect pests of cowpea in north-eastern Nigeria.
Source: International Journal of Pest Management. 2010. 56[3]:243-253.

Seed Treatments Could Increase Food Production in Africa

Roots

Seedling Disease: no treatment (L) seed treatment (R)

Seeds may be attacked by insects and pathogens once planted in the soil. Treating seed with insecticides and fungicides is commonplace in the U.S. and other developed countries. Contact insecticides and fungicides coated on the seed create a protective barrier on the seed that slows or stops the insects and pathogens from attacking the seed. In Africa, seed treatments are not widely-used to protect seeds planted by small-scale farmers and crop losses occur. Research shows that the use of seed treatments could substantially increase African crop production.

“Disease and insect attacks are an important constraint for crop productivity in the drylands of West Africa. A test was therefore included to find out whether treating seeds with a combined fungicide/insecticide could increase yields. The results showed that the treatment of seeds increased yields by 17% on average, compared with untreated seeds. A previous study showed that the average yield increase due to seed treatment with fungicide/insecticide was 30% for pearl millet in West Africa.

This study shows how low-cost options can increase agricultural productivity in the millet-producing areas of Mali.”

Authors: Aune, J. B., C. O. Traore, and S. Mamadou
Affiliation: Norwegian University of Life Science.
Title: Low-cost technologies for improved productivity of dryland farming in Mali.
Source: Outlook on Agriculture. 2012. 41[2]:103-108.