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Sowing experiments April 24th, 2022 by

For nearly a century, from 1839 to 1924, the US government distributed free seeds to any citizen who wanted them. As told in First the Seed, by Jack Kloppenburg, seeds of field crops, vegetables and even flowers were sourced from around the world (often by the US Navy). The seed was multiplied in the USA, and mailed through the post by members of Congress to their constituents. The program was wildly popular and by 1861, the first year of the American Civil War, almost two and a half million seed packages (each with five packets of seed) were being shipped each year to farmers and gardeners.

As Kloppenburg explains, given the botanical knowledge of the time, and the limited ability of formal agricultural research in the United States, the free seed for farmers “was the most efficient means of developing adapted and improved crop varieties.”

I recently saw a little window into this seed program. On 7 April 2022, The Times-Independent (a newspaper in Moab, Utah), published a replica of their page one from exactly 100 years earlier. One short story, “Seeds Go Quickly” showed just how much people loved free seed. The little story reads:


SEEDS GO QUICKLY

In last Thursday’s issue, The Times-Independent announced that a quantity of government seeds had been received by this office for distribution to the people of Moab, and inviting those who wanted some of the seeds to call for them. Within a few minutes after the paper was delivered to the post office, local people commenced to call for the seeds, and there was a continuous demand until the supply was entirely exhausted.


I hadn’t realized that newspapers also helped to distribute the seed. In 1922, Moab’s local newspaper did not bother telling its readers what the “government seed” was. They knew it well, even though today the program is forgotten. Kloppenburg says that the government seed was not only free, but of high quality, better than what private companies were then able to supply. This partly explains the rush of townspeople clamoring seed at The Times-Independent office, but farmers’ love of innovation was also a reason for the excitement. The farmers and gardeners who swung open the glass door of the newspaper office didn’t know what kind of seed was in the little packages. There was some mystery there: each package contained several packets of different seed. Each packet was just a handful of seed, enough to try out, but not enough to plant a field.

The free seed sparked thousands of farmer experiments over decades, which formed the basis of modern, North American agriculture.

The development of the adapted base of germplasm on which American agriculture was raised is the product of thousands of experiments by thousands of farmers committing millions of hours of labor in thousands of diverse ecological niches over a period of many decades.

Jack Kloppenburg, First the Seed, page 56

In the early 1800s seed companies were small, but they were growing. By 1883 these companies organized as the American Seed Trade Association (ASTA) and immediately began to lobby against government seed. Free seed was so popular that it took ASTA forty years, until 1924, to finally convince Congress to kill the program, at the height of its popularity.

Since 1922, companies have largely wrested control of seed from farmers, who once produced and exchanged all of the seed of field crops. It’s worth remembering that small gifts of seed sparked farmer experiments that shaped American agriculture.

Further reading

Kloppenburg, Jack Ralph, Jr. 1990 First the Seed: The Political Economy of Plant Biotechnology, 1492-2000. Cambridge University Press.

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Soil for a living planet January 30th, 2022 by

In a refreshingly optimistic book, The Soil Will Save Us, Kristin Ohlson explains how agriculture could stop emitting carbon, and instead remove it from the air and place it in the soil.

Soil life is complex. A teaspoon of soil may harbor between one and seven billion living things. Microorganisms like fungi and bacteria give mineral nutrients to plants in exchange for carbon-rich sugars. Predatory protozoa and nematodes (worms) then eat the fungi and bacteria, releasing the nutrients from their bodies back to the soil.

When people add chemical fertilizer to the soil, these living things die, essentially starved to death as the plants no longer need to interact with them. The plants become dependent on chemical fertilizer. Reading this in Ohlson’s book reminded me of farmers in Honduras and around the world, who have been telling me for over 30 years that soil quickly “becomes used to,” or “accustomed” to chemical fertilizers. Local knowledge is often ahead of the science.

When soil is plowed, it loses some of its carbon. The plow lets in air that binds with the carbon to become C02, which rises into the atmosphere. Plowed soil is broken, and more prone to erosion than natural, plant-covered earth. One of the many people Ohlson interviewed for her book, innovative North Dakota farmer Gabe Brown, grows a biodiverse mix of cover crops, including grasses and legumes. But instead of harvesting these crops, Brown lets his cows graze on them. Then he drills corn (maize) or other cash crops into the soil, instead of plowing it. No chemical fertilizers are applied. This soil is productive, while saving labor and expense, and absorbing carbon instead of giving it off. This healthy soil holds more water than plowed soil, so the crops resist droughts. Brown developed this system working with Innovative scientists like Jay Furhrer and Kristine Nichols of the US Department of Agriculture (USDA), an example of the power of collaborative research.

Brown is not the only farmer trying to conserve the soil, but when Ohlson was writing about a decade ago, only 4.3% of US farmland was enrolled in any kind of government land conservation program.

Encouraging more farmers to conserve the soil will require public universities to do more research on no-till farming i.e., forsaking the plow and encouraging cover crops and livestock grazing to boost soil fertility. Universities have to stop accepting grants from companies that produce the chemical fertilizer, the pesticides and the genetically modified crop seeds that tolerate them. Accepting corporate money diverts university research into chemical farming, even though taxpayers still pay the faculty members’ salaries and society pays the price for soils becoming unproductive in the long-term.

Fortunately, there is much that we can all do at home, in gardens, parks and even lawns. The biggest irrigated crop in the United States is not maize, but lawns, which take up three times as much space as corn. Lawns can be managed without chemicals: fertilized with compost, while clover and other legumes can be planted among the grass to improve the soil. Families can make compost at home and fertilize the garden with it. City parks can also sequester carbon. The Battery Park in Manhattan is fertilized entirely with compost and compost tea (a liquid compost).

I was encouraged by this book. Agriculture could be the solution to climate change, and even help to cool the planet, rather than being a major contributor to the problem.

Get involved

In 2015, just after Ohlson’s book was published, some 60 people from 21 countries met in Costa Rica and formed Regenerative Agriculture, an international movement united around a common goal: to reverse global warming and end world hunger by facilitating and accelerating the global transition to regenerative agriculture and land management. Click here to find a partner organization in your area.

Further reading

Ohlson, Kristin 2014 The Soil Will Save Us: How Scientists, Farmers and Foodies Are Healing the Soil to Save the Planet. New York: Rodale. 242 pp.

Related Agro-Insight blogs

Hügelkultur

Capturing carbon in our soils

Community and microbes

Living Soil: A film review

A revolution for our soil

Out of space

Videos on how to improve the soil

See some of the many videos on soil management hosted by Access Agriculture.

 

Innovating with roots, tubers and bananas January 16th, 2022 by

A new book edited by Graham Thiele and colleagues of the CGIAR Research Program on Roots, Tubers and Bananas (RTB) highlights research over the past decade on a remarkable group of crops that are grown from vegetative seed (such as cuttings and roots). Crops include potato, sweetpotato, cassava, yam and bananas, all of which were domesticated in the tropics and are a big part of the daily diet in many developing countries. Continued research on these crops is important to keep family farmers competitive, and to keep producing food locally in tropical countries.

One chapter of the book describes how cassava is becoming an ever more important crop in West Africa, both for food and for manufacturing (flour, starch and alcohol), yet this has led to a new problem. Cottage processors and food manufacturers are creating mounds of peels, rotting in the open air. Nigerian researcher Iheanacho Okike and colleagues describe their innovation to turn garbage to gold by converting peels into livestock feed. Various feed makers are now making cassava peels into meal, as a substitute for imported maize.

The potato currently enjoys high demand across Africa, where it can be grown at higher altitudes. But a bottleneck has been getting access to disease-free seed, especially of new varieties that farmers want. A chapter by Elmar Schulte-Geldermann and colleagues discuss techniques that can be used by national agricultural programs or local companies to produce lots of seed quickly, using aeroponics and rooted apical cuttings (two methods for growing potato plants from cuttings in nurseries). This seed is distributed to seed producers, who rear and sell seed for farmers.

Margaret McEwan and colleagues describe Triple S (storage in sand and sprouting), a way for smallholders to conserve sweetpotato seed roots during the dry season in nothing more complicated than sand pits lined with mud bricks.

Agricultural researchers have been urged for years to work more closely with farmers, but often with limited guidance about how to do so. This book fills some of that gap. Vivian Polar and other gender experts have a chapter on methods that plant breeders can use to ensure that new crop varieties meet the needs of women and men.

Jorge Andrade-Piedra and colleagues discuss methods for studying seed systems, usually managed entirely by farmers, with little outside influence. These practical study methods would be beneficial to any development organization or project interested in understanding local seed systems before engaging with them.

These and other chapters feature the agronomy and social innovations of yams, sweetpotatoes, cassava, potatoes and bananas. Few books compile the results of agricultural research over ten years, by such a large group of scientists. The results show the value of publicly-funded research to benefit smallholder farmers in the tropics.

Further reading  

Thiele, Graham, Michael Friedmann, Hugo Campos, Vivian Polar and Jeffery W Bentley (Eds.) 2022. Root, Tuber and Banana Food System Innovations Root, Tuber and Banana Food System Innovations: Value Creation for Inclusive Outcomes. Springer, Cham.

The book will be out soon, and can be pre-ordered online from various book-dealers.

Farmers know how to keep seed healthy January 2nd, 2022 by

Vea la versión en español a continuación

Agricultural scientists have long concluded that the seed of some crops degenerates steadily with each planting. This is especially true for crops that are planted vegetatively, for example through cuttings or tubers, like the potato. Degeneration is the buildup of pests and diseases, passed one from one generation to the next in vegetative seed, slowly lowering the crop’s yield.

A recent, long-term study by Ecuadorian plant scientist, Israel Navarrete, was able to reconfirm this, but only in experiments, not in farmers’ fields. In experimental plots at different altitudes in the high Andes, potatoes originally planted from certified (healthy) seed acquired more viruses and other pathogens every year, for three years.

However, Navarrete found no evidence of seed degeneration on Ecuadorian farms. He surveyed 260 households, to collect information on how they grew potatoes. A typical survey stops there, but Navarrete also collected a seed sample from each family. Later, in the laboratory, he diagnosed these seed potatoes for pests and diseases.

Counter to conventional wisdom, Navarrete found that farmers’ seed was not degenerating. Potatoes grown on the same farm for over ten years were as healthy as those cultivated only recently. The reason, Navarrete explains, is that farmers have their own methods for keeping seed healthy. For example, farmers in Ecuador often select seed, searching through the piles of tubers, picking out the best ones. They also store seed until it sprouts, which seems to improve its health. Other farmers stored seed in bags or applied fertilizer. From his survey, some 36 local practices were identified that influenced seed health.

The farmers themselves knew they were doing something right. Only 16%, said that degeneration was a problem for them, although they were aware of it. When seed degenerates, Ecuadorian farmers say that it has become “tired.” Then they replace it.

Of course, not all local habits make for healthy seed. When potato prices soar, farmers are often tempted to sell as much as possible, even some of the tubers that would make good seed.

Navarrete encourages other agricultural scientists to learn about seed health from farmers. Later, scientists can recommend helpful new ideas to the farm families. Navarrete and colleagues have a few such suggestions, such as encouraging farmers to grow a small, special field as a seed lot, where the healthiest plants can be saved as the mothers of next year’s seed.

This study shows the limits of the experimental method, which looks at one variable at a time. The real world of farming is messy. Seed may degenerate in a carefully controlled experiment, but not so much in the field, because farmers manage it. Researchers may be keen to show how seed degenerates, while farmers are working to avoid it.

Further reading

Navarrete, Israel 2021 Seed Degeneration of Potato in the Tropical Highlands of Ecuador. Ph.D. thesis. Wageningen University, The Netherlands. 234 pp.

Related Agro-Insight blog

Eating the experiment

Video of interest

Using sawdust to store potatoes

Acknowledgements

Israel Navarrete works at the International Potato Center (CIP). This research recently earned him a Ph.D. at Wageningen University, in The Netherlands.

MANTENIENDO LA SEMILLA SANA EN ECUADOR

Jeff Bentley 2 de enero del 2022

Hace rato los científicos agrícolas han concluido que la semilla de algunos cultivos degenera cada vez que se siembra, especialmente los cultivos que se siembran vegetativamente, por ejemplo mediante esquejes o tubérculos, como la papa. La degeneración es la acumulación de plagas y enfermedades, que se transmiten de una generación a otra en la semilla vegetativa, reduciendo lentamente el rendimiento del cultivo.

Un reciente estudio a largo plazo realizado por el científico de plantas ecuatoriano, Israel Navarrete, logró reconfirmar esto, pero sólo en experimentos, pero no en los campos de los agricultores. En parcelas experimentales a diferentes alturas en los altos Andes, las papas sembradas originalmente con semilla certificada (sana) adquirieron más virus y otros patógenos cada año, durante tres años.

Sin embargo, Navarrete no encontró pruebas de degeneración de las semilla en las granjas ecuatorianas. Encuestó a 260 hogares para recoger información sobre cómo cultivaban las papas. Las encuestas no suelen hacer nada más para reconfirmar los datos, pero Navarrete también recogió una muestra de semillas de cada familia. Más tarde, en el laboratorio, diagnosticó esta papa semilla en busca de plagas y enfermedades.

En contra de la opinión generalizada, Navarrete descubrió que las semillas de los agricultores no se degeneraban. Las papas cultivadas en la misma granja durante más de diez años estaban tan sanas como las cultivadas recientemente. La razón, explica Navarrete, es que los agricultores tienen sus propios métodos para mantener las semillas sanas. Por ejemplo, los agricultores de Ecuador suelen seleccionar las semillas, buscando entre los montones de tubérculos, escogiendo los mejores. También almacenan las semillas hasta que brotan, lo que parece mejorar su salud. Otros agricultores almacenan las semillas en sacos o aplican fertilizantes. A partir de su encuesta, se identificaron unas 36 prácticas locales que influían en la salud de las semillas.

Los mismos agricultores sabían que estaban haciendo algo bien. Sólo el 16% dijo que la degeneración era un problema para ellos, aunque eran conscientes de ello. Cuando la semilla se degenera, los agricultores ecuatorianos dicen que se ha “cansado”. Entonces la reemplazan.

Por supuesto, no todas las costumbres locales hacen que la semilla sea sana. Cuando los precios de la papa se disparan, algunos agricultores no pueden resistir la tentación y venden todo lo posible, incluso algunos de los tubérculos que serían buena semilla.

Navarrete anima a otros científicos agrícolas a aprender de los agricultores sobre la salud de las semillas. Posteriormente, los científicos pueden recomendar nuevas ideas útiles a las familias de agricultores. Navarrete y sus colegas tienen algunas sugerencias de este tipo, como animar a los agricultores a cultivar un pequeño campo especial como lote de semillas, donde las plantas más sanas puedan guardarse como madres de las semillas del año siguiente.

Este estudio muestra los límites del método experimental, que analiza una variable cada vez. El mundo real de la agricultura es desordenado. Las semillas pueden degenerar en un experimento cuidadosamente controlado, pero no tanto en el campo, porque los agricultores las gestionan. Los investigadores pueden estar interesados en mostrar cómo degenera la semilla, mientras que los agricultores trabajan para evitarlo.

Lectura adicional

Navarrete, Israel 2021 Seed Degeneration of Potato in the Tropical Highlands of Ecuador. Ph.D. thesis. Wageningen University, The Netherlands. 234 pp.

Anteriormente en el blog de Agro-Insight

Experimentos que se comen

Video sobre la papa

Almacenando papas en aserrín

Agradecimientos

Israel Navarrete trabaja en el Centro Internacional de la Papa (CIP). Presentó esta investigación para obtener su doctorado en la Universidad de Wageningen, en los Países Bajos.

 

 

Different ways to learn November 21st, 2021 by

Vea la versión en español a continuación

In June I wrote a story about a virtual meeting with some farmers in Iquicachi, on the shores of Lake Titicaca (Zoom to Titicaca), where they discussed how to manage what was (for them) a new pest: the potato tuber moth. Later, several people wrote to me to say that they hoped these farmers could solve their problem. So I’m writing an update.

I went to Lake Titicaca on 16 November to meet the farmers in person, and they’re doing well.

The agronomists they work with taught them to use ground chalk from a building supply shop to coat the seed potatoes. The chalk discourages the tiny larva of the moth from burrowing into the potato. This and some other techniques are helping to keep the tuber moth down.

At our recent meeting, I was impressed (as I often am) how scientists and farmers have different ways of seeing the world. There’s nothing mystical about his. It’s because they use different methods of observation.

An entomologist sees an insect by killing some specimens and looking at them under the microscope. It is an excellent way to see the details of nature that cannot be readily seen with the naked eye. For example, one of the three species of tuber moths has triangular markings on its wings.

But the farmers of Titicaca were less interested in comparing each species of moth, and more intent on comparing them to another pest, one they have had for ages: the Andean potato weevil.

These Yapuchiris (expert farmers) and their neighbors noticed that the moths’ larvae are much smaller than the worms that hatch from weevil eggs. Second, the weevil only eats a part of the tuber, while the larvae of the moth “have no respect for the potato” and destroy the whole thing. Third, the weevil can’t fly, but the moth “flies in jumps” (it takes short flights).

In all fairness, entomologists have also noticed these behaviors, and the Yapuchiris have recently observed that one species of moth is darker than the other. But the farmers emphasize behavior more, and have their own rhetoric for discussing it (e.g. as jumping). Note that this is not ancestral knowledge, because this pest is new on the Altiplano. These Yapuchiris only noticed the moth 10 years ago, and they have been observing it since then. The farmers learn about insects while farming and processing food. They watch while they work. They don’t set up lab experiments.

The Yapuchiris have strengthened their observations by interacting with agronomists. In this case the extensionists explained that the moths are the adults of the worms, so the farmers then began to pay more attention to the moths.

These improved observations have paid off.

While I was in Iquicachi, one of the Yapuchiris, Martín Condori, suggested that since the tuber moth does not fly very far, it could be kept out of potatoes by planting a row of broad beans or lupin beans between every three rows of potatoes. It’s a new idea, that only occurred to don Martín while we were meeting.

His fellow Yapuchiri, Paulino Pari, immediately warmed to don Martín’s suggestion for an intercropping experiment. Don Paulino said that a row of lupin beans might help to stop the moth from spreading into the potatoes, because the lupin plants are toxic to the moths.

This is the value of farmer-scientist collaboration. The farmers learn that the worms in their potatoes have hatched from the eggs laid by moths. Farmers then pay more attention to the moths, and create new ideas for keeping the moths out of the potato field.

Intercropping may or may not help to manage the moth, but it is an idea that farmers and agronomists can try together.

Years ago in Honduras, Keith Andrews, an entomologist, first told me that farmers identify insects more by their behavior and ecology than by their morphology. I’ve spent many years noticing that he was right.

Acknowledgements

A special thanks to Ing. Roly Cota, who works at PROSUCO, for taking me to Iquicachi and introducing me to the Yapuchiris, so we could validate three new fact sheets for farmers on the potato tuber moth. Our work was supported by the  Collaborative Crop Research Program (CCRP) of the McKnight Foundation.

Photo credit

Photo courtesy of Roly Cota.

Further reading

There is some excellent research on the potato tuber moth. For example, see this paper and references cited.

Olivier Dangles, Mario Herrera, Charlotte Mazoyer and Jean-François Silvain 2013 Temperature-dependent shifts in herbivore performance and interactions drive nonlinear changes in crop damages. Global Change Biology 19, 1056–1063, doi: 10.1111/gcb.12104.

Scientific names

There are two native tuber moths in Bolivia: Symmetrischema tangolias, and Phthorimaea operculella. There is also a Guatemalan tuber moth, Tecia solanivora, but it has not been reported in Bolivia. All three of these moths belong to the Gelechiidae family. They are about a centimeter long, about as long as your smallest fingernail. Many Gelechiidae attack stored cereal products, and so you may have been alarmed to find them in your cupboard.

Video on the fascinating lupin bean

Growing lupin without disease

APRENDIENDO CON OTROS OJOS

Por Jeff Bentley, 21 de noviembre del 2021

En junio escribí un relato sobre una reunión virtual con los agricultores de Iquicachi, a orillas del lago Titicaca (Zoom al Titicaca), en la que se discutía cómo gestionar lo que era (para ellos) una nueva plaga: la polilla de la papa. Más tarde, varias personas me escribieron para decirme que esperaban que estos agricultores pudieran resolver su problema. Así que escribo una actualización.

El 16 de noviembre fui al Lago Titicaca para conocer a los agricultores en persona, y están bien.

Los agrónomos con los que trabajan les enseñaron a usar tiza molida de una tienda de materiales de construcción para recubrir la papa semilla. La tiza no deja que la pequeña larva de la polilla penetre a la papa. Esta y otras técnicas están ayudando a reducir la polilla de la papa.

En esta última reunión, me impresionó (como en muchas veces) cómo los científicos y los agricultores tienen formas diferentes de ver el mundo. No tiene nada de místico. Es porque usan distinto métodos de observación.

Un entomólogo observa un insecto al matar algunos ejemplares y mirándolos al microscopio. Es una forma excelente de ver los detalles que no se pueden ver fácilmente a simple vista. Por ejemplo, una de las tres especies de polillas de la papa tiene marcas triangulares en las alas.

Pero los campesinos del Titicaca estaban menos interesados en comparar cada especie de polilla, y más en compararlas con otra plaga, una que tienen desde hace mucho tiempo: el gorgojo de los Andes.

Estos Yapuchiris (agricultores expertos) y sus vecinos se dieron cuenta de que las larvas de las polillas son mucho más pequeñas que los gusanos que nacen de los huevos del gorgojo. En segundo lugar, el gorgojo sólo se come una parte del tubérculo, mientras que las larvas de la polilla “no respetan la papa” y la destruyen completamente. En tercer lugar, el gorgojo no puede volar, pero la polilla “vuela a saltos” (have vuelos cortos).

En realidad, los entomólogos también se han dado cuenta de estos comportamientos, y los Yapuchiris han observado recientemente que una especie de polilla es más oscura que la otra. Pero los campesinos enfatizan más el comportamiento, y tienen su propia retórica para discutirlo (los saltos, por ejemplo). Fíjese que no se trata de un conocimiento ancestral, porque esta plaga es nueva en el Altiplano. Estos Yapuchiris sólo se dieron cuenta de la polilla hace 10 años, y desde entonces la observan. Los campesinos aprenden sobre los insectos mientras cultivan y procesan los alimentos. Observan mientras trabajan. No hacen experimentos de laboratorio.

Los Yapuchiris han reforzado sus observaciones interactuando con los agrónomos. En este caso, los extensionistas les explicaron que las polillas son los adultos de los gusanos, por lo que los agricultores comenzaron a prestar más atención a las polillas.

Estas observaciones mejoradas han dado sus frutos.

Durante mi visita a Iquicachi, uno de los Yapuchiris, Martín Condori, sugirió que, como la polilla de la papa no vuela muy lejos, se podría sembrar un surco de tarwi (lupino) entre cada tres surcos de papa, para que no entre la polilla. Es una idea nueva, que sólo se le ocurrió a don Martín mientras nos reuníamos.

Otro Yapuchiri, don Paulino Pari, aceptó inmediatamente la sugerencia de don Martín de hacer un experimento de cultivo intercalado. Don Paulino dijo que un surco de tarwi podría ser una barrera para la polilla, porque las plantas de tarwi son tóxicas para las polillas.

Este es el valor de la colaboración entre agricultores y científicos. Los agricultores se enteran de que los gusanos de sus papas han nacido de los huevos puestos por las polillas. Los agricultores prestan entonces más atención a las polillas y crean nuevas ideas para mantener las polillas fuera del campo de papas.

Los cultivos intercalados pueden ayudar o no a controlar la polilla, pero es una idea que los agricultores y los agrónomos pueden probar juntos.

Hace años, en Honduras, Keith Andrews, un entomólogo, me explicó por primera vez que los agricultores identifican a los insectos más por su comportamiento y ecología que por su morfología. Llevo muchos años comprobando que tenía razón.

Agradecimientos

Muchas gracias al Ing. Roly Cota, quien trabaja en PROSUCO, por llevarme a Iquicachi y convocar una reunión con los Yapuchiris, donde pudimos validad tres nuevas hojas volantes para agricultores sobre la polilla de la papa. Nuestro trabajo ha sido auspiciado por el Programa Colaborativo de Investigación sobre Cultivos (CCRP) de la Fundación McKnight.

Foto

Foto cortesía de Roly Cota.

Lectura adicional

Hay varios excelentes trabajos de investigación sobre la polilla de la papa. Por ejemplo, vea este artículo y los otros en las referencias citadas.

Olivier Dangles, Mario Herrera, Charlotte Mazoyer and Jean-François Silvain 2013 Temperature-dependent shifts in herbivore performance and interactions drive nonlinear changes in crop damages. Global Change Biology 19, 1056–1063, doi: 10.1111/gcb.12104.

Nombres científicos

Hay dos polillas de la papa nativas en Bolivia: Symmetrischema tangolias, y Phthorimaea operculella. Además, hay una polilla guatemalteca de la papa, Tecia solanivora, pero no ha sido reportada en Bolivia. Las tres polillas pertenecen a la familia Gelechiidae. Miden más o menos un centímetro, más o menos lo largo de su uña meñique. Muchos Gelechiidae atacan cereales almacenados, y es posible que le hayan sorprendido en su dispensa.

Video sobre el fascinante tarwi

Producir tarwi sin enfermedad

El mismo video, en el idioma aymara

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