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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

Experiments with trees October 24th, 2021 by

Vea la versión en español a continuación

Farmers find their peers exceptionally convincing, and good extensionists know this.

My wife, Ana, and I joined a farmer exchange visit this past 22 September. It was a chance for smallholders to see what their peers are doing on their farms. We went with about 20 farmers from around Tiquipaya, a small town in the valley of Cochabamba, Bolivia. Except for two older men and two children, the group was made up only of women, organized by María Omonte (agronomist) and Mariana Alem (biologist), both of Agrecol Andes.

Half an hour after our chartered, Bluebird bus left the town square of Tiquipaya we were climbing up a gravel road in first gear. The farmers stopped chatting among themselves, and began looking out the window, at the arid hillsides and a panoramic view of the city of Cochabamba, on the far end of the valley. The passengers’ sudden interest in the scenery made it clear that even this close to home, this was their first trip to these steep hillsides above the community of Chocaya.

When the bus stopped, we were met by Serafín Vidal, an agronomist, also with Agrecol Andes. Serafín took the group to see an agroforestry site, an orchard belonging to a farmer who Serafín advises. The farmer wasn’t there, but Serafín explained that in this system, 200 apple trees are planted in lines with 200 forest trees, like chacatea (blue sorrel) and aliso (alder), mostly native species. The idea is to mimic the forest, which builds its own soil, with no plowing, no pesticides (not even organic ones), and no fertilizer, not even manure or compost.

“Don’t bury anything” Serafín said, “not even leaves. They decompose too quickly if you bury them. Just prune the forest trees and line up their branches in between the apples and the other trees.”

The farmers were quiet, too quiet. They seemed unconvinced by this radical idea. Finally, one farmer was bold enough to give a counter-example. He said that far away, in the lowlands of La Paz Department, farmers dig a trench and fill it with logs and branches. They bury it and plant coca, a shrub with marketable leaves. Because of the buried logs, the land stays fertile for so long that even the grandchildren of the original farmer will not need to fertilize their soil.

“Coca,” Serafín murmured, and then he paused. Growing the coca shrub is not like planting apples, but a talented, veteran extensionist like Serafín often prefers a demonstration to an argument. He dug his hand into the soil between the trees, under the leafy mulch. “This used to be poor, red soil. But see how the soil between the trees has become so soft that I can dig it up with my hand, and it’s rich and black, even though it has not been plowed.” Serafín spread out a couple of dozen small bags of seed of different plants: maize, beans, vegetables … all crops that you can plant in between the rows of trees, like the plants that grow on the forest floor.

The audience was respectfully silent, and still unconvinced, but Serafín had another trick up his sleeve. He handed the floor over to a local farmer, Franz Dávalos, who led us uphill to his own agroforestry plot, with alder, and the native qhewiña (Polylepsis spp.), a tree with papery, reddish bark and twisted branches.

The group was mostly bilingual in Spanish and in Quechua, the local language, and had been switching back and forth between both languages.  But now Franz began to speak only in Quechua. The simple act of speaking in the local language can let the audience feel that the speaker is confiding in them, and Franz soon had them laughing as he explained how his neighbors grew flowers, like chrysanthemum, to cut for the urban market. In the dry season they irrigate with sprinklers. The neighbors were baffled that Franz didn’t irrigate during the two driest winter months, June and July. He didn’t want to fool the apple trees into flowering too early. It meant that for a couple of months, his patch looked dry and bare. But now his three-year-old apple trees were blooming and looking healthy, as were his other trees, bushes, aromatic plants, tomatoes and beans.

The visiting farmers were from the floor of the valley, practically in sight of this rocky hillside, but it might as well have been a different country. The flat fields of the valley bottom have flood irrigation and deep soil, but exhausted by centuries of constant cultivation.

One of the visitors explained that she was a vegetable farmer and that “we have already made big changes. I apply chicken manure to my soil and I have to spray something (like a homemade sulfur-lime mix) because the aphids just won’t leave us alone.”

In other words, these people from the valley bottom were commercial, family farmers, far into their transition to agroecology, based on natural pesticides and organic fertilizers to restore the degraded soil. And they had to build up the soil quickly, because they were growing vegetables year-round. They couldn’t just give up applying organic fertilizer and wait for years until trees improved the soil.

Franz understood completely. He said that he also sprayed sulfur-lime but then he said “just try it. Try agroforestry on a small area, even if you just start with one tree.”

It was a cheerful group that boarded the bus to go down the mountain. They liked Franz’s suggestion of experimenting on a small scale, even with such a startling new idea as agroforestry.

Paleontologist Richard Fortey says that scientists are usually so reluctant to accept the ideas of younger colleagues that “science advances, one funeral at a time.” (Fortey was quoting Max Planck). Smallholders are a little more open to new ideas. As farmers continue to contribute to agroecology, they will discuss and experiment. It is not reasonable to expect all of them to accept the same practices, especially when they are working in different places, with different crops and soils.

But a word from an innovative farmer can help to make even radical ideas seem worth testing.

Related Agro-Insight blogs

Apple futures (where we’ve met Ing. Serafín Vidal before)

Farming with trees

Training trees

Related videos

SLM03 Grevillea agroforestry

SLM08 Parkland agroforestry

SLM10 Managed regeneration

EXPERIMENTOS CON ÁRBOLES

Por Jeff Bentley, el 24 de octubre del 2021

Lo que más convence a los agricultores, es otro agricultor, y los buenos extensionistas lo saben.

Con mi esposa, Ana, participamos el pasado 22 de septiembre en una visita de intercambio de agricultores, una oportunidad para que vean lo que hacen sus compañeros en sus terrenos. Fuimos con unos 20 agricultores de los alrededores de Tiquipaya, una pequeña ciudad del valle de Cochabamba, Bolivia. Con la excepción de dos hombres mayores y dos niños, el grupo estaba formado sólo por mujeres, organizado por María Omonte (agrónoma) y Mariana Alem (bióloga), ambas de Agrecol Andes.

Media hora después de que nuestro viejo bus saliera de la plaza del pueblo de Tiquipaya, estábamos subiendo a 10 km la hora por un camino ripiado, pero bien inclinado. Las compañeras dejaron de charlar entre ellas y empezaron a mirar por las ventanas a las áridas laderas y una vista panorámica de la ciudad de Cochabamba, en el otro extremo del valle. El repentino interés de los pasajeros por el paisaje dejaba claro que, incluso tan cerca de casa, era la primera vez que viajaban a estas inclinadas laderas de Chocaya Alta.

Cuando el micro se detuvo, nos recibió Serafín Vidal, ingeniero agrónomo, también de Agrecol Andes. Serafín llevó al grupo a ver un sitio agroforestal, un huerto que pertenece a un agricultor al que asesora. El agricultor no estaba allí, pero Serafín explicó que en este sistema se plantan 200 manzanos en línea con 200 árboles forestales, como la chacatea y el aliso, con énfasis en especies nativas. La idea es imitar al bosque, que construye su propio suelo, sin arar, sin fumigar (ni siquiera con plaguicidas orgánicos) y sin estiércol.

“No entierren nada”, dice Serafín, “ni siquiera las hojas. Se descomponen demasiado rápido si las entierran. Sólo poden los árboles del bosque y alineen sus ramas entre los manzanos y los otros árboles”.

La gente estaba callada, demasiado callada. Parecían no estar convencidos de esta idea radical. Finalmente, un agricultor se atrevió a dar un contraejemplo. Dijo que muy lejos, en Los Yungas de La Paz, los cocaleros cavan una zanja y la llenan con troncos y ramas. Lo entierran y plantan coca, un arbusto comercial. Gracias a los troncos enterrados, la tierra se mantiene fértil durante tanto tiempo que incluso los nietos del agricultor original no necesitarán fertilizar su suelo.

“Coca”, murmuró Serafín, y pausó. Cultivar arbustos de coca no es como plantar manzanos, pero un veterano y talentoso extensionista como Serafín suele preferir una demostración a una discusión. Metió la mano en la tierra entre los árboles, bajo el grueso mulch, el mantillo, el sach’a wanu. “Antes, esto era un suelo pobre y rojo. Pero miren cómo el suelo entre los árboles se ha vuelto tan blando que puedo cavarlo con la mano, y es rico y negro, aunque no haya sido arado”. Serafín extendió unas 20 bolsitas de semillas de diferentes plantas: maíz, frijol, hortalizas … todos los cultivos que se pueden sembrar entre las hileras de los árboles, tal como las plantas que crecen en el piso del bosque.

El público guardaba un respetuoso silencio, y todavía no estaba convencido, pero Serafín tenía otro as en la manga. Cedió la palabra a un agricultor de la zona, Franz Dávalos, que nos condujo cuesta arriba hasta su propio sistema agroforestal, con alisos y la nativa qhewiña (Polylepsis spp.), un árbol de corteza rojiza, como papel, con ramas retorcidas.

La mayoría del grupo era bilingüe en español y en quechua, el idioma local, y había alternado entre ambas lenguas.  Pero ahora Franz empezó a hablar sólo en quechua. El simple hecho de hablar en el idioma local puede dar confianza al público, y rápidamente Franz los hacía reír mientras explicaba cómo sus vecinos cultivaban flores, como el crisantemo, para vender como flor cortada al mercado urbano. En la época seca riegan por aspersión. Los vecinos se preguntaban porque Franz no regaba durante los dos meses más secos del invierno, junio y julio. Es que él no quería que los manzanos florezcan demasiado temprano. Por eso, durante un par de meses, su parcela parecía seca y desnuda. Pero ahora sus manzanos de tres años florecían y estaban obviamente sanos, al igual que sus otros árboles, arbustos, y otras plantas como aromáticas, tomates y frijoles.

Las agricultoras visitantes eran del fondo del valle, prácticamente a la vista de esta ladera rocosa, pero bien podría haber sido otro país. Las chacras planas del fondo del valle tienen riego por inundación y un suelo profundo, pero agotado por siglos de cultivo constante.

Una de las visitantes explicó que ella era agricultora de hortalizas y que “ya hemos hecho muchos cambios. Aplico gallinaza a mi suelo y tengo que fumigar algo (como sulfocálcico) porque los pulgones no nos dejan en paz”.

En otras palabras, estas personas del piso del valle eran agricultores comerciales y familiares, que estaban en plena transición hacia la agroecología, basada en plaguicidas naturales y fertilizantes orgánicos, para restaurar el suelo degradado. Y tenían que recuperar el suelo rápidamente, porque cultivaban verduras todo el año. No podían dejar de aplicar abono orgánico y esperar años hasta que los árboles mejoraran el suelo.

Franz lo entendía perfectamente. Dijo que él también fumigaba sulfocálcico, pero luego dijo “pruébenlo. Prueben la agroforestería en una pequeña superficie, aun si empiezan con un solo árbol”.

Fue un grupo alegre el que subió al micro para bajar del cerro. Les gustó la sugerencia de Franz de experimentar a pequeña escala, incluso con una idea tan nueva y sorprendente como la agroforestería.

El paleontólogo Richard Fortey dice que los científicos suelen ser tan reacios a aceptar las ideas de los colegas más jóvenes que “la ciencia avanza, un funeral a la vez”. (Fortey citaba a Max Planck). En cambio, los agricultores familiares están un poco más abiertos a las nuevas ideas. A medida que los agricultores sigan contribuyendo a la agroecología y la agroforestería, discutirán y experimentarán. No es razonable esperar que todos ellos acepten las mismas prácticas, sobre todo cuando trabajan en lugares diferentes, con cultivos y suelos distintos.

Pero una palabra de un agricultor innovador puede ayudar a que incluso las ideas radicales parezcan dignas de ser probadas.

Blogs previos de Agro-Insight blogs

Manzanos del futuro (donde ya conocimos al Ing. Serafín Vidal)

La agricultura con árboles

Training trees

Videos sobre la agroforestería

SLM 03 Agroforestería con grevillea

SLM08 Agroforestería del bosque ralo

SLM10 Regeneración manejada

Eating the experiment July 25th, 2021 by

Vea la versión en español a continuación

Even though farmers and agricultural scientists share the same field of study, they have completely different experimental styles.

This past year in Ecuador, Ph.D. candidate Israel Navarrete was encouraging farmers to experiment, and he was struck by how much time it took them just to pick a research question. While organizing three small groups of farmers in the province of Cotopaxi, Israel found that the local people could take up to three meetings just to pick a topic. Some farmers felt that the other group members weren’t listening to them. (Hurt feelings are as normal in peasant communities as in university departments).

One of Israel’s small groups, made up entirely of women, was dedicated to growing potatoes and black maize. Like the farmers I wrote about recently from Lake Titicaca, the Ecuadorian women had problems with tuber moths destroying their seed potatoes. These farmers from Cotopaxi eventually decided to see if they could control the moths by treating their seed potatoes with garlic extract and with “cementina” (a local type of construction lime).

Israel encouraged them to do multiple replicates of the experiment. Replicates (simultaneous repetitions of the experiment) are a hallmark of the scientific method, and they are especially important in agriculture where each plot of earth, each batch of seed is slightly unique, like snowflakes. An idea has to be tried several times to see if the result is consistent, and is not just a chance occurrence.

But the farmers of Cotopaxi declined to use replicates, and simply tried the lime and garlic on one batch of seed. The solution seemed to work, so Israel encouraged the women to try it again, perhaps in different treatments (such as the lime alone, or the garlic alone, and both together). But the farmers refused. They were satisfied with the results.

As Israel explained this experience, he tried to hide his frustration that the farmers would not work on the experiment in more detail. He was philosophical about the results. He said, “The farmers take a complicated idea and test it in a simple way, while researchers take a simple idea, and test it in a complicated way.”

Much of the scientific method is designed to show universal truth. The experiment has to be replicable and described in numbers and published. After the data is collected, the experiment can be thrown away.

For the farmers, the experiment doesn’t have to be replicable. It only has to achieve results on their farm. It doesn’t need numbers because the farmers are looking for large qualitative differences. You either get rid of the tuber moths, or you don’t. And unlike the scientists, the farmers have to make a living from the actual experiment. In this case, the farmers planted the seed potatoes they had dusted with lime and garlic.

The scientists write up the experiment and publish. It is part of their job. The farmers learn from the experiment and then eat it. It is part of their life.

In spite of having remarkably different experimental styles, collaboration between smallholders and researchers is most valuable for the insights farmers have from years of making a living on the farm. A biologist may never have come up with the idea of fighting the tuber moth with lime and garlic.

People of different professions can have different goals and methods, even when they work on the same topic, which is all the more reason why they should share ideas with each other.

Related blog stories

Zoom to Titicaca

Acknowledgement

Israel Navarrete is an Ecuadorian expert on seed health, and a Ph.D. candidate at the University of Wageningen, in the Netherlands. His research is funded by the International Potato Center (CIP) and the McKnight Foundation’s Collaborative Crop Research Program (CCRP).

Further reading

Bentley, Jeffery W. 1994 “Facts, Fantasies and Failures of Farmer Participatory Research.” Agriculture and Human Values 11(2&3):140-150.

Photo

Photo by Veronika Vogel, courtesy of Israel Navarrete

 

EXPERIMENTOS QUE SE COMEN

Jeff Bentley 25 de julio del 2021

Aunque los agricultores y los científicos agrícolas comparten el mismo campo de estudio, tienen estilos experimentales completamente diferentes.

El año pasado, en Ecuador, el estudiante de doctorado Israel Navarrete animó a los agricultores a experimentar, y le llamó la atención el tiempo que les llevaba sólo elegir una pregunta de investigación. Mientras organizaba tres pequeños grupos de agricultores en la provincia de Cotopaxi, Israel descubrió que los lugareños podían tardar hasta tres reuniones sólo para elegir un tema. Algunos agricultores sentían que los otros miembros del grupo no les escuchaban. (Las roces y resentimientos son tan comunes en las comunidades campesinas como en los departamentos universitarios).

Uno de los pequeños grupos de Israel, formado exclusivamente por mujeres, se dedicaba a cultivar papas y maíz negro. Al igual que los agricultores y agricultoras del Lago Titicaca sobre las que escribí hace poco, las ecuatorianas tenían problemas con las polillas de la papa que destruían su semilla de papa. Estas agricultoras de Cotopaxi decidieron finalmente ver si podían controlar las polillas tratando su semilla con extracto de ajo y con “cementina” (un tipo de cal para la construcción).

Israel les animó a hacer múltiples réplicas del experimento. Las réplicas (repeticiones simultáneas del experimento) son un fundamento del método científico, y son especialmente importantes en la agricultura, donde cada parcela de tierra, cada lote de semillas es algo único, como los copos de nieve. Hay que probar una idea varias veces para ver si el resultado es consistente y no es una mera casualidad.

Pero las agricultoras de Cotopaxi se negaron a usar réplicas y se limitaron a probar la cal y el ajo en un solo lote de semilla. La solución pareció funcionar, por lo que Israel animó a las mujeres a probarlo de nuevo, tal vez en diferentes tratamientos (como la cal sola, o el ajo solo, y ambos juntos). Pero las agricultoras se negaron. Estaban satisfechos con los resultados.

Al explicar esta experiencia, Israel trató de ocultar su frustración de que los agricultores no quisieran trabajar en el experimento con más detalle. Se mostró filosófico sobre los resultados. Dijo: “Los agricultores toman una idea complicada y la prueban de forma sencilla, mientras que los investigadores toman una idea sencilla y la prueban de forma complicada”.

Gran parte del método científico está diseñado para mostrar una verdad universal. El experimento tiene que ser replicable y estar descrito en números y publicado. Una vez recolectados los datos, el experimento puede desecharse.

Para los agricultores, el experimento no tiene que ser replicable. Sólo tiene que conseguir resultados en su finca. No necesita números porque los agricultores buscan grandes diferencias cualitativas. O se elimina la polilla de la papa, o no. Y a diferencia de los científicos, los agricultores tienen que vivir del experimento en sí. En este caso, los agricultores sembraron la semilla de papa que habían rociado con cal y ajo.

Los científicos redactan el experimento y lo publican. Es parte de su trabajo. Los agricultores aprenden del experimento y se lo comen. Es parte de su vida.

A pesar de tener estilos experimentales bien diferentes, la colaboración entre los pequeños agricultores y los investigadores es valiosa por los conocimientos que tienen los agricultores tras años de ganarse la vida trabajando la tierra. Puede que a un biólogo no se le haya ocurrido nunca la idea de combatir la polilla del tubérculo con cal y ajo.

Personas de distintas profesiones pueden tener objetivos y métodos diferentes, incluso cuando trabajan en el mismo tema, y justo por eso vale la pena que compartan ideas entre sí.

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Agradecimiento

Israel Navarrete es un experto ecuatoriano en la sanidad de las semillas, y candidato a PhD en la Universidad de Wageningen, en los Países Bajos. Su investigación está financiada por el Centro Internacional de la Papa (CIP) y el Programa Colaborativo de Investigación de Cultivos (CCRP) de la Fundación McKnight.

Lectura adicional

Bentley, Jeffery W. 1990 “La Participación de los Agricultores en Hechos, Fantasías y Fracasos: Introducción a la Memoria del Simposio.” Ceiba 31(2):29-41.

Foto

Foto por Veronika Vogel, cortesía de Israel Navarrete

 

Youth don’t hate agriculture June 20th, 2021 by

Rural youth are moving to the cities by the busload. Yet counter to the prevailing stereotype, many young people like village life and would be happy to go into farming, if it paid. This is one of the insights from a study of youth aspirations in East Africa that unfolds in three excellent country studies written by teams of social scientists, each working in their own country. Each study followed a parallel method, with dozens of interviews with individuals and groups in the local languages, making findings easy to compare across borders.

In Ethiopia many young people grow small plots of vegetables for sale, and would be glad to produce grains, legumes, eggs or dairy. Youth are often attracted to enterprises based on high-value produce that can be grown on the small plots of land that young people have.

Young people are also eager to get into post-harvest processing, transportation and marketing of farm produce, but they lack the contacts or the knowhow to get started. Ethiopian youth have little money to invest in farm businesses, so they often migrate to Saudi Arabia where well-paid manual work is available (or at least it was, before the pandemic).

In northern Uganda, researchers found that many youths wanted to get an education and a good job, but unwanted pregnancies and early marriage forced many to drop out of secondary school. If dreams of moving to the city and becoming a doctor, a lawyer or a teacher don’t work out, then agriculture is the fallback option for many young people. But, as in Ethiopia, young Ugandan farmers would like their work to pay more.

In Tanzania, many youths have been able to finish secondary school and some attend university. Even there, young people go to the city to escape poverty, not to get away from the village. Many youths are even returning, like one young man who quit his job as a shop assistant in town to go home and buy a plot of land to grow vegetables. Using the business skills he learned in town, he was also able to sell fish, and eventually invested in a successful, five acre (two hectare) cashew farm.

These three insightful studies from East Africa lament that extension services often ignore youth. But the studies also suggest to me that some of the brightest youth will still manage to find their way into agriculture. Every urban migrant becomes a new consumer, who has to buy food. As tropical cities mushroom, demand will grow for farm produce.

If youth want to stay in farming, they should be able to do so, but they will need investment capital, and training in topics like pest management and ways to make their produce more appealing for urban consumers. Improved infrastructure will not only make country life more attractive, but more productive. Better mobile phone connectivity will link smallholders with buyers and suppliers. Roads will help bring food to the cities. A constant electric supply will allow food to be processed, labeled and packaged in the countryside. New information services, including online videos, can also help give information that young farmers need to produce high-value produce.

Further reading

These three studies were all sponsored by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT). You can find them here.

Boonabaana, Brenda, Peace Musiimenta, Margaret Najjingo Mangheni, and Jasper Bakeiha Ankunda 2020. Youth Realities, Aspirations, Transitions to Adulthood and Opportunity Structures in Uganda’s Dryland Areas. Report submitted to ICRISAT.

Endris, Getachew Shambel, and Jemal Yousuf Hassan 2020. Youth realities, aspirations, transitions to adulthood and opportunity structures in the drylands of Ethiopia. Report submitted to ICRISAT.

Mwaseba, Dismas L., Athman K. Ahmad and Kenneth M. Mapund 2020. Youth Realities, Aspirations and Transitions to Adulthood in Dryland Agriculture in Tanzania. Report submitted to ICRISAT.

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Some videos of interest

Access Agriculture hosts videos to share information about profitable, ecologically-sound agriculture. Farmers of all ages can download videos on their smartphones in English and many other languages, for example:

For Ethiopia, check out these videos in Amharic, Oromo, Afar, and Arabic, Oromo,

For Tanzania, 122 videos in Swahili (Kiswahili), and others in Dholuo, and Tumbuka

For Uganda, Ateso, Kalenjin, Kiswahili, Luganda, Lugbara, Luo (Uganda), Runyakitara

To find videos in a language of your country, click here.

Silent Spring, better living through biology June 13th, 2021 by

Hey farmer, farmer

Put away that DDT now

Give me spots on my apples

But leave me the birds and the bees

Please!

“Big Yellow Taxi,” by Joni Mitchell

It’s possible that Joni Mitchell’s 1970 lyrics owe a debt to Rachel Carson’s (1962) book Silent Spring. Why not? The book was a major influence on the environmental movement, inspiring Earth Day, the Environmental Protection Agency (EPA), and the US ban on DDT, besides. Less often mentioned, the book also touched off integrated pest management (IPM).

For all that, Carson makes few mentions of farmers in her book. Many of the cases she meticulously described are of the US and Canadian governments arrogantly dropping insecticide from airplanes, blanketing forest, field, stream, pasture, and even suburban communities.

DDT and other noxious organophosphate insecticides were applied in each case to kill some specific pest: The Japanese beetle, the spruce budworm, and the fire ant, for example.

In every case, the results were disastrous. Dead livestock, and cancer in humans, but the birds were decimated. The bald eagle, national bird of the USA, was nearly exterminated by DDT. The bald eagle has since made a comeback, but many other bird species are on the decline.

The chemical companies that sold these pesticides to the government had the audacity (or the stupidity) to claim that insects would not be able to evolve resistance to the toxins. The pests would be eradicated!

But they weren’t. The bugs won the war. In every single case, the target pest species was more numerous a few years after the spraying started.

To explain this, Carson coined the analogy of the pesticide treadmill. Before a pesticide is used, an insect’s population is controlled by its natural enemies, such as spiders, wasps, ants, and birds. Insecticide kills the pest, and its natural enemies, too. The pest evolves resistance to the pesticide, much quicker than do its natural enemies (which often reproduce more slowly and absorb more of the poison). Once freed from its natural enemies, the pest population explodes. Now it has to be managed by pesticides.

In 1962, Carson mused that Darwin would have been pleased to see how well his theories were proven, as insect pests had quickly evolved resistance to pesticides. If Carson were here today, she might not be so happy to see how the chemical companies have also evolved. They have engineered maize and soy varieties that can withstand herbicides, so fields can be sprayed with glyphosate that kills all the plants, except for the ones with designer genes. The corporations that sell the seed conveniently sell the herbicide as well. Companies like Monsanto once claimed that the weeds would not be able to evolve resistance to the genetically modified crops.

But they did. At least 38 species of weeds are now resistant to glyphosate.

As Carson said nearly 60 years ago (and it’s still true), farms and forests are biological systems. Their pest problems have to be solved with biology, not with chemistry. In Rachel Carson’s day, only 2% of economic entomologists were working on biological pest control. Most of the other 98% were studying chemicals. Funding for chemicals breeds contempt for biological alternatives.

Biological pest control uses natural enemies to control pests. Carson cites the famous case of the cottony cushion scale, a citrus pest in California. The pest was controlled in 1872, long before DDT was available, by importing a lady bird beetle from Australia that ate the scale insects. The scale insects then became rare in California orchards until the 1940s, when insecticides killed the lady bird beetles and the pests exploded.

A recent book by Biovision and IPES Food suggests that many big donors still fund conventional research in pesticides. Perhaps it’s time to invest in scientists who can pick up Rachel Carson’s challenge, and solve biological problems with biology.

Further reading

Carson, Rachel 1962 (1987 edition). Silent Spring. Boston: Houghton Mifflin.

Heap, Ian, and Stephen O. Duke 2018 “Overview of glyphosate‐resistant weeds worldwide.” Pest Management Science 4(5): 1040-1049.

On chemical companies denying that weeds would develop resistance to their herbicides see chapter 5 in:

Philpott, Tom 2020 Perilous Bounty: The Looming Collapse of American Farming and How we can Prevent It. New York: Bloomsbury Publishing. 246 pp. (See also a review of this book in Our threatened farmers).

Biovision Foundation for Ecological Development & IPES-Food. 2020. Money Flows: What Is Holding Back Investment in Agroecological Research for Africa? Biovision Foundation for Ecological Development & International Panel of Experts on Sustainable Food Systems

Videos on natural, biological pest control

The wasp that protects our crops

Killing fall armyworms naturally

Weaver ants against fruit flies

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