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

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.

Angry Italian Women Replaced by Herbicides

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Le Mondine of the 1950s                                                                      Riso Amaro “Bitter Rice”

In Italian rice fields in the 1950s prior to the development of herbicides, weeding was done by hand. In May, the rice fields had to be weeded to prevent the young rice from being choked by other vegetation. Hundreds of women known as le mondine, or weeders, arrived from all parts of Italy to perform the delicate task of rooting out the weeds while leaving the young rice plants in place. Le mondine have become a nostalgic memory, immortalized by the famous film Riso Amaro or ‘Bitter Rice.’ It was a hard life for le mondine. They had to work bent double, up to their knees in water under a blazing sun. As the women weeded, they sang. One of the songs, Bella Ciao, was adopted by the Italian Communist Party to express the social injustice of the system. In the 1960s, most of the women left the rice fields when jobs opened up in cities, such as Milan, Genoa, and Turin. Today, herbicides are used in Italian rice fields.

“Italy is the largest rice producer in Europe, with about 235,000 ha in 2012. The main rice cultivation area is concentrated in the north-western regions of Piedmont and Lombardy where the continuous paddy rice system is widespread. Weed management is one of the key aspects of rice cultivation because pedo-climatic conditions are favourable to weeds that are generally competitive, there is a rich and persistant seed bank, and the weed flora is often dominated by difficult-to-control species… Consequently, farmers need to apply complex chemical and agronomic strategies to guarantee good weed control. Herbicide use is intense, with an average treatment frequency index higher than 2.5.”

Authors: Scarabel, L, et al.
Affiliations: National Research Council, Italy.
Title: Resistance evolution and sustainability of the rice cropping system: the Italian case study.
Source: Global Herbicide Resistance Challenge: Program and Abstracts. February 18-22, 2013. Pg. 105.

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.

Tea Leaves Need Protection from Fungal Blisters

Funky Green Leaves

Blister Blight on Tea Leaves

Leaf diseases are very important in tea production since the plants are grown for their young leaves. The major foliar disease of tea in Asia is blister blight. Wind-borne spores germinate on the leaf in humid conditions and the leaf is penetrated. Further growth presses out and eventually a blister is formed on the leaf. Each blister can produce up to 20 million spores. Tea prepared from blistered leaves is weak, with poor color, aroma, brightness, and briskness. Before the use of fungicides, tea losses to blister blight were staggering with 30-50% losses. Preventive copper sprays have been the mainstay of tea production for the past 60 years. Blister blight is not a problem for organic tea growers since they are permitted the use of copper sprays.

Tea is one of the most popular beverages in the world owing to its taste, the stimulative effect, and also for its health benefits. Perennial habit of the tea plant, peculiar cultural conditions and warm humid climate of the tea growing areas are highly conducive for disease development… Among the leaf diseases, blister blight caused by Exobasidium vexans is the most important one. The disease is known to occur in almost all tea growing areas of Asia. E. vexans is an obligate parasite with no alternate host. Hence, its life cycle has to be completed on tea plant itself. The entire life cycle is completed in 11 days under conducive weather conditions or else it could extend up to 28 days… Comparisons between the crop harvested from tea fields protected by fungicide spray and those left unsprayed indicated a loss of 50% to blister blight disease in six months.”

Authors: Sowndhararajan, K., et al.
Affiliations: School of Life Sciences, India.
Title: Integrated control of blister blight disease in tea using the biocontrol agent Ochrobactrum anthropi strain BMO-111 with chemical fungicides.
Source: Journal of Applied Microbiology. 2013. 114:1491-1499.

Eat Your Lima Beans, They are Not Moldy

Lima Beans: the Good, the Bad, and the Edible.

Lima Beans: moldy (L); Fungicide Treated (R)

Lima bean has been an important crop grown for canning and freezing in the mid-Atlantic area of the United States since the nineteenth century. Lima bean grown for processing is planted on 6,500 hectares in Delaware, with production valued at $6.5 million. 13,000 hectares of lima bean are grown in the United States, with California being the largest producer of lima bean and Delaware being second. Lima bean is considered to be the cornerstone crop of the vegetable processing industry in Delaware, and Delaware remains one of the few states that produce the crop. Lima bean downy mildew was first reported in Connecticut in 1889, and the disease is in Delaware almost every growing season.

“Currently, P. phaseoli [lima bean downy mildew] is limited to the mid-Atlantic areas of Delaware, Maryland, and New Jersey and has never been reported to occur in California. This is likely to be due, at least in part, to California’s lower humidity compared with the eastern United States.

In 1958, P. phaseoli was responsible for an epidemic, with more than 907,185 kg of bean loss from 4,725 hectares in Delaware. In 2000, race E of P. phaseoli was responsible for an epidemic in Delaware during September and October, which resulted in an estimated production loss of 40%, equal to a farm value loss of $3,000,000.

Fungicide testing for control of downy mildew of lima beans began as early as 1897 when Bordeaux mixture was recommended for control.

Growers currently make preventative applications of copper fungicides either alone or in combination with insecticides for pod-feeding insects. When conditions for downy mildew are favorable and outbreaks occur, applications of Ridomil Gold/Copper (mefenoxam) or Phostrol are made curatively to unsprayed fields or those where copper fungicides have been applied preventatively.

Currently, several fungicides are labeled and effective for control of downy mildew if applied in a timely manner. Ridomil Gold/Copper (mefenoxam/copper), Phostrol (phosphorus acid salts), and copper fungicides are currently labeled on lima bean and are effective.”

Authors: Evans, T. A., et al.
Affiliations: Department of Plant and Soil Sciences, University of Delaware.
Title: Lima bean downy mildew: impact, etiology, and management strategies for Delaware and the mid-atlantic region, U.S.
Source: Plant Disease. 2007. 91[2]:128-135.

Rain: A Huge Risk When Not Using Herbicides

Tractor in a Field

Cultivator Stuck in a Wet Field

Farmers who use herbicides to control weeds have great flexibility in the timing of applications. Farmers who use cultivation to remove weeds do not have much flexibility. Cultivation must be done when weeds are small. If a field is too wet for a tractor to enter, cultivation cannot be done and the weeds continue to grow and cause crop yield loss. Recent research shows that the wet field problem is common and that relying on cultivation instead of herbicides results in a yield loss of about 26% one-third of the time.

“Wet weather during the early part of the growing season was the major reason that mechanical weed control was difficult in some years.

This variability fit our observations of the trials that there was a large range in annual grain yields in the organic systems depending on how favorable the weather was for mechanical weed control.

The field crew reported problems controlling weeds in the organic systems in 1993 and 1998 at Elkhorn and 1993, 1996, 2000, and 2001 at Arlington.

Based on the above summary, we estimate that the frequency of weed control problems and subsequent reduced yields in low-input row crops is roughly 34 out of every 100 cases and the corresponding relative yield is approximately 74%.”

Authors: Posner, J. L., et al.
Affiliation: Department of Agronomy, University of Wisconsin.
Title: Organic and conventional production systems in the Wisconsin integrated cropping systems trials: I. productivity 1990-2002.
Source: Agronomy Journal. 2008. 100[2]:253-260.

The Brazilian Soybean Miracle That Almost Didn’t Happen

Spraying For Soybean Rust

Spraying For Soybean Rust

Soybean production in Brazil grew rapidly since 1960 with area expanding from 400,000 hectares to 22 million hectares. Brazil is a major soybean producer-62 million tons per year. In 2001, soybean rust was first detected in Brazil and by 2003 the pathogen had spread to the entire country with yield losses up to 75% in individual fields. If fungicides are not used, Brazil would lose about 50% of its soybean production annually.

“More than 50 different fungicidal products are currently labeled for managing soybean rust in Brazil, and many of these have been evaluated annually since 2003/2004 in a nationwide network of standardized, uniform field trials (UFTs) coordinated by Embrapa Soja, a research unit of the Brazilian Agricultural Research Corporation.

We present a meta-analytical synthesis of the results of 71 uniform fungicide trials containing 930 entries (specific fungicidal treatments) conducted in Brazil from 2003/2004 to 2006/2007. …on average, fungicide treatments… increased yield by 43.9%.

The results of this analysis showed that fungicidal control of soybean rust in Brazil is highly effective… (indicating a relative disease reduction of between 90 and 100% in response to treatment). …these comparisons show that, despite favorable environmental conditions for soybean rust epidemics in Brazil, the disease can be managed very effectively with modern fungicides.”

Authors: Scherm, H, et al.
Affiliation: Department of Plant Pathology, University of Georgia.
Title: Quantitative review of fungicide efficacy trials for managing soybean rust in Brazil.
Source: Crop Protection. 2009. 28:774-782.

They’re Only in it for the Money: Organic Farming in the EU

Organic Farmers in Greece

Organic Farmers in Greece

Organic farming regulations are implemented by EU Member States mainly through the provision of financial support to farmers. There has been an increase in the areas under organic management in most EU countries, which is probably related to the direct effect of financial support. Greece is an important country with respect to organically cultivated land and has one of the highest rates of increasing organic areas in the EU. However, Greek organic products are very difficult to find in the market, and sales are extremely low. In other words, only a small amount of organic products are labeled and sold as organic products. Since farmers were willing to switch from conventional to organic agriculture, with the procedure to obtain the organic label being quite simple for farmers to follow, why are so many farmers not enthusiastic about certifying and labeling their products as organic?

“In Greece, organic farming was majorly promoted through the provision of subsidies to farmers, i.e., since 2004. An average organic farmer in Greece has one of the highest per hectare support compared to other countries. However, subsidies are provided with no limitation regarding crop type, geographic region or other more specific characteristics. It is very likely that farmers are not selecting organic management for ideological reasons, but are driven by financial incentives to receive the available subsidies… In any case, when the organic agricultural sector operates in this way, it stops at the farm, resulting in it being short term and highly unsustainable, as it is completely dependent on direct and uninterrupted financing. 

Consequently, since organic farming is made profitable because of subsidies (sometimes double, as in the case of wheat), it is much easier for the farmers to sell organic products as conventional products in a market that they are already familiar with.

As the majority of EU Member States offer per area payments for the conversion and/or maintenance of organic land, the “Bio without Bio”, i.e., organic farming – without organic products case of Greece, is probably not an exception.”

Authors: Argyropoulos, C., et al.
Affiliation: DIO-Certification Body.
Title: Organic farming without organic products.
Source: Land Use Policy. 2013. 32:324-328.

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.