Rambo meets Mr. Bean
If a crop were a film star, what would cassava be? Well a month ago we established that cassava was a Rambo root – very difficult to kill. It’s well known resistance to drought and heat was shown to stand up to climate change in our paper in Tropical Plant Biology. Most interesting in that article was that cassava thrives whilst other major staples suffer. Beans, a crucial crop for East Africa, was shown to be particularly sensitive. Mr Bean?
Joking apart, this means that the adaptation entry points for beans and cassava are vastly different. For beans, we need to find ways of making the crop, and the farming system it is grown in, less exposed to changes in climate. That might be through improved management, or through the development of climate smart crops which are far more resistant to the likely climatic constraints that are going to be experienced in the future. For cassava, the crop has great potential to BE an adaptation strategy. It could be a fallback option on a farm, one that will produce even if all other crops fail. It may also be a substation crop in marginal areas, which gains ground when all other staples gradually become unsustainable. So the very fact that it is not particularly vulnerable does not mean that we should not concentrate on it. Quite the opposite, we need more cassava in order to adapt.
But it might be too early to claim victory. Our paper highlighted two big research issues that we must address. First, cassava is blighted by pests and diseases, be it viruses in Africa or insects in Asia. There’s still a lot of work to be done to understand if climate change will exacerbate these problems. We think they might, but we need better models on pest and disease interactions with climate and host plants. The second issue was the need for better models of cassava growth and production. In the paper we used a simple niche-based model, largely because a robust mechanistic model is not available for cassava. So whilst we rely on very advanced physiological models for many other crops, for cassava we do not have that luxury. This needs to change.
And so that is where we are heading now. Improving the models to allow us not only to say that cassava is or is not vulnerable to climate change, but to understand better the physiology of the plant, and explore avenues for improving its management and delivering better varieties to farmers. This week we are presenting (see slides at the bottom of this post) these results in the Global Cassava Partnership Second Scientific Conference (GCP21-II) in Kampala, Uganda. The highlight of the presentation is a call for action to improve our knowledge about cassava growth and its relationships with climate and pests and diseases. We are hoping to pull together an (informal) consortium of researchers interested in developing better trial and on-farm data for cassava, and the generation of a solid mechanistic model for cassava. And our doors are open, so take this as an invitation to contribute data and knowledge to this initiative. We hope within a year to have a functioning cassava model under the DSSAT umbrella of crop models, so that we may really test cassava’s biology and its capacity to be THE adaptation option for Africa. Drop us a line if interested by leaving a comment and we’ll be in touch.