Aid organisations often do participatory varietal selection (PVS) trials with smallholders in developing countries as an easy way of identifying suitable varieties for them to introduce. Their extensionists generally choose the varieties to be trialled, except local checks to be chosen by the smallholders. The smallholders grow, consume and/ or sell the the crop and share feedback with the aid organisation/ their extensionists.

One of its earliest and best-known successes was the introduction of climbing common bean varieties for Rwandan smallholders (Louise Sperling, 1996). Rwanda has a very high population density and the researchers knew that climbing beans had a greater yield than the dwarf varieties then grown. The extra food this achieved would thus more than justify the extra effort of staking them.

This work involved international research funded by overseas aid. The researchers chose the crop and test varieties, exploiting their specialist knowledge. The Rwandan smallholders grew different varieties of climbing bean varieties in their smallholdings to see how well each would grow and their households tested the eating acceptability of the beans; both provided feedback to Louise.

Several climbing bean varieties were selected by the smallholders; these are now widely grown in Rwanda, proving the value of PVS.

I was working in Uganda at Namulonge Research Station with the national Sweet Potato Programme when I heard of this work. At that time, most Ugandan sweet potato varieties were susceptible to a severe disease called sweet potato virus disease but the Sweet Potato Programme had recently bred five varieties that were resistant.

We decided to use PVS to trial our resistant sweet potato varieties with smallholders. Before our project, most sweet potato in Uganda was grown in the Eastern Region where sweet potato virus disease is rare.

Our trials were in Central Uganda where sweet potato virus disease was rampant so we thought all our varieties would be winners: we were really thinking of the trials as demonstrations for the smallholders!

At each of several locations, the smallholder owners planted small plots of the new varieties along with their current favourite in their holdings. All the yield belonged to the smallholder; she and her family probably ate most of it and sold the rest. And we found out what they thought of each variety.

All the varieties resisted the virus. Yet only one, NASPOT 1, was approved by the smallholders.

NASPOT 1 absolutely hit the jackpot. It is now grown intensively in Central Uganda, close to the main market in the capitol Kampala. For several years it was the most widely grown variety in Uganda. It also spread to neighbouring countries.

But why were the other four varieties rejected? To our then amazement, the smallholders in our PVS trial had over fifty different reasons why they liked/ didn’t like a particular variety; they were quite pernickety. On-station plant breeding allowed selection for only half-a-dozen or so traits.

So perhaps we should instead have been surprised that at least NASPOT 1 was selected! And using a PVS approach allowed us to understand why this was so.

 

The next webpage explains how PPB then became more widely used in developed countries amongst specialist growers, especially organic growers.