When people talk about climate change, images of disastrous droughts and scorched crop fields come to mind. Yet, climate change is not only about extreme weather. As ICRISAT’s principal scientist Vincent Vadez explains, moderate temperature increases induce many negative effects on what a plant will yield. A warmer climate means plants grow faster but this “early maturity” could mean less biomass and less grain.
Some plants like millets (pearl, finger millet or sorghum to name a few) have adapted to produce grain in dry and hot environments limiting plant water loss (what scientists call evapo-transpiration) through various physiological mechanisms. In some parts of sub-Saharan Africa, farmers are shifting from maize to growing more drought-tolerant sorghum cereal crops.
A recent modelling study concluded that sorghum would be more productive than maize under the negative impact of climate change in central Tanzania. The study's researchers hope their predictions will enable policy makers to plan sustainable farming solutions.
Largescale policy changes are needed to facilitate changes in cropping systems. Recent commitments from global agribusiness and leading researchers are key drivers for change. An alliance between Dupont Pioneer, Agropolis Foundation and Heartland Global calls for more investment on traditional climate resilient crops like millets and sorghum for Africa. In addition to developing better seeds with greater yields, climate resilience and nutritional value, this new framework will rethink the local seed systems and better link dryland cereal farmers to the marketplace to speed up adoption.
As Vadez explains in the video, the critical role of phenotype research in identifying and developing new drought tolerant varieties is a hidden side of climate change adaptation solutions. There is a great genetic variability in the ability of plants to restrict water losses under high evaporative demand (eg in hot and dry weather). This means that in warmer temperatures, some plant varieties save enough water to cope with dry spells when filling their grain (what Vadez calls terminal drought tolerant) while other plants will dry out without any grain. ICRISAT has developed a giant and clever field scanner called Leasyscan with their partner Phenospex, which is able to screen thousands of plants per hour, under field-type conditions, measuring a combination of plant characteristics several times a day. Leasyscan has helped Vadez and his colleagues to build a huge phenotyping database which is then used to select the varieties that do well under water stress.
Through conventional yet smart plant breeding, ICRISAT aims to create new drought-tolerant and productive varieties in a faster way, so that smallholder farmers in Africa or South Asia have the right climate adapted crops to cope with a 2 degrees warmer climate.