What are the Barriers to Engineering Perennial, High-yield Grain Crops?

By Mike Abram 

Perennial grain crops –those you only plant once before harvesting multiple times – would potentially deliver many favourable on-farm attributes – not least savings in seed and fuel costs, reduced cultivations and lower input requirements.

Research has also shown increased carbon sequestration, improved soil structure, reduced soil erosion risk and better nutrient use efficiency.

But while progress is being made by researchers to create perennial grain crops, with rice, wheat and near-wheat relatives already commercialised or close to it, there remains significant barriers before they become widespread – not least extremely low yields in some cases.

Creating a perennial grain crop is far from easy. There are two main methods: either domesticating a perennial species that has desirable characteristics, such as consistently high seed yields, synchronous flowering and seed maturation, or crossing an existing annual grain crop with a wild perennial cousin.