In early 1974 I travelled to southern Peru with a taxonomist friend from the University of St Andrews, Dr Peter Gibbs.

Peter and I had become friends when he visited the International Potato Center (CIP) in 1973. At that time Peter was supervising the Master’s thesis of a Peruvian student, Martha Vargas (daughter of renowned Peruvian botanist Professor César Vargas from Cuzco). At CIP he wanted to see if he could hitch a ride to the south of Peru on any germplasm collecting trips planned to that region, so that he could make some collections of oca (Oxalis tuberosa), a minor Andean tuber crop.

As it happened, I was looking to carry out some ethnobotanical studies on the different potato varieties grown by farmers as part of my PhD research – but where would be a good site?

Peter showed me an old scientific paper (from 1951) by WH Hodge from the University of Massachusetts [1] about the cultivation of different tuber crops, including potatoes and oca, in the village of Cuyo Cuyo, located about 140 km northeast of Puno (69˚50’W, 14˚50’S) at the head of the Sandia Gorge. Well, this seemed like too good an opportunity to miss, and we agreed to pool our resources for the trip.

The drive south in a small Land Rover – down the coastal desert Panamericana highway, across the Nasca plain, climbing to Arequipa, and even higher to Puno – took three days. After resting up in Puno (next to Lake Titicaca), and getting used to the 3827 m altitude, we set off for Cuyo Cuyo. Dropping down from the altiplano at well over 4000 m, Cuyo Cuyo lies at an altitude of about 3300 m. Below the village the valley drops quickly towards the ceja de la montaña – literally ‘eyebrow of the mountain’ – where the humid air of the rainforests below rises up east-facing valleys to form cloud forest.

No-one in Cuyo Cuyo was expecting us, so there were quite a few surprised faces when these two gringos drove into town. Cuyo Cuyo was not on the ‘research-tourist’ trail in 1974, but many researchers have visited Cuyo Cuyo since I was there (see below), and there are quite a few publications now about the socio-economic systems and agriculture there.

Under these circumstances (as on other germplasm collecting trips) I’d found it useful to find the local mayor (alcalde) or schoolteacher and explain what we were up to and have them in turn explain to the local farmers and their families (in Quechua). On a previous trip to the north of Peru in May 1973, a local schoolteacher (rather drunk at the time as we’d arrived on his village’s fiesta) hailed me as a representative of La Reina Isabel (HM The Queen), promptly calling a village meeting, and asked me to give a ‘loyal address’. At that time I had fairly rudimentary Spanish, but it didn’t matter. After a few words of congratulations for the fiesta, every person in the hall (maybe 200 or so) came and shook me by the hand!

Peter and I set up camp, so-to-speak, in the local post office where we could sleep, brew the odd cup of tea (there was a small café in the village where we could eat), and gather our specimens together, including a rudimentary drier for the extensive set of oca herbarium samples that Peter intended to make. But more of that particular story later.

The sides of the Cuyo Cuyo valley are covered with the most wonderful system of agricultural terraces, called andenes, which must have been constructed centuries ago, in Inca times, and have been cultivated ever since. Farmers have different terraces dotted around the valley, and when I was there, at least, farmers were still using a communal rotation system. Thus in one part of the valley the terraces were covered in potatoes (year 1 after a fallow), and oca (years 2 and 3), barley or beans (year 4), or fallow (years 5-8) elsewhere. Sheep are corralled on a terrace prior to planting potatoes, and their urine and dung used as fertilizer. Whether, almost 40 years later, this remains the case I do not know.

But this system of potato and oca cultivation allowed me to make some detailed studies of the diversity of potato fields in terms of varieties grown and their genetic make-up (chromosome number). I eventually published this work in Euphytica in 1980 [2]. And there’s a story about that publication that’s also worth repeating, a little later on.

Since the terraces are quite small, only the native foot plough is used to till the soil (see my earlier post about potatoes). I discovered that different varieties were apparently suited to the growing conditions in different parts of the valley. The most highly prized varieties with a high dry matter content, termed harinosa or floury, were grown on the upper terraces where there was little chance of flooding. Whereas on the valley floor, which was flooded from time-to-time, farmers grew varieties which tended to be more ‘watery’ and used preferentially in soups.

Another very interesting discovery, for me at least, was seeing freshly harvested potatoes dipped in a clay paste after cooking. This practice, known generally as geophagy, has been reported from many societies, as well as observed in animals and birds.

Farmers told me that freshly harvested potatoes (but not the so-called bitter potatoes – see below) tended to be somewhat ‘peppery’ (that’s the best word I can find to describe the sharp taste of some varieties), and that dipping the tubers in the clay paste helped not only with digestion but also reduced the sharpness of the taste. One of the farmers showed me the site where they collected lumps of clay that were then ground to a fine powder and mixed with water. What’s interesting, however, is that I did not find any frost tolerant, bitter potatoes (Solanum juzepczukii or Solanum curtilobum) that have to be processed to make chuño before they can be eaten.

After two or three days, Peter and I felt that we’d done sufficient field work there, and headed north towards Cuzco to visit some additional sites. From there we returned to Lima by air, leaving the Land Rover behind for a CIP colleague.

But what about all those oca herbarium specimens? Despite our best efforts, we had great difficulty in drying the specimens that Peter collected, for two reasons. It was quite wet during our visit to Cuyo Cuyo, and all the samples were covered in moisture even before we attempted to turn them into dried herbarium sheets. Furthermore, oca has rather fleshy stems that just wouldn’t dry. Even after a couple more weeks of drying in Lima, Peter packed up what he had and posted them to St Andrews. After he arrived home, he found that his herbarium specimens were not only alive, but had begun to sprout – so he promptly planted them all in his university glasshouse, and had a range of living samples to use in his study of pollination mechanisms!

And what about the ethnobotany paper that I referred to earlier? I completed my PhD in 1975, and began to write-up my work for publication in scientific journals. I chose the Wageningen-based journal Euphytica for two papers submitted in 1977 on triploid potatoes and crossability studies, and Economic Botany for the Cuyo Cuyo paper. Well, that paper was finally accepted by mid-1977, and I waited for it to appear in print (by that time I’d already moved to Costa Rica and was busy with other potato research).

I didn’t hear anything for many months, but then, out of the blue, I received a letter from the new Editor-in-Chief of Economic Botany asking me if I’d published the paper elsewhere. In taking over the helm at Economic Botany, he’d found manuscripts in the files that had been accepted for publication up to two decades earlier, but had never been published! Well, at about the same time, the Editor of Euphytica, Prof. Anton Zeven, wrote to me, commenting on my PhD thesis (he’d obtained a copy through interlibrary loan) and wondering if I had published my Cuyo Cuyo research. And if I hadn’t, would I seriously consider doing so. What an invitation! With some revisions (but unfortunately removal of some of the more anthropological aspects) I submitted the paper to Euphytica in early 1979, and it was published some months later in 1980.

Cuyo Cuyo in 2006
Among the researchers to have visited Cuyo Cuyo more recently than me – in early 1997 and May 2006 – is University of Wisconsin-Madison associate professor of botany Dr Eve Emshwiller, who has been studying oca for many years now. In a recent message (15 March 2014)  she commented that Cuyo Cuyo was a fascinating place, but changing fast. I’m sure that’s something that could be said about many of the places I visited in the 1970s, then quite remote, but now opened up through better roads and telecommunications. Eve has kindly given me permission to include here some of her wonderful photos taken in 2006 of the oca harvest in Cuyo Cuyo. In one of the photos you can see the patchwork of fields, some with oca, others with potatoes. That cropping system certainly hadn’t changed in more than 30 years.

[1] Hodge, WH, 1951. Three native tuber foods of the high Andes. Economic Botany 5 (No. 2): 185-201.

[2] Jackson, MT, JG Hawkes and PR Rowe, 1980. An ethnobotanical field study of primitive potato varieties in Peru. Euphytica 29: 107-113. Click to read the paper in full.