In the heart of the tropics, where droughts are becoming increasingly frequent due to climate change, farmers are looking for crops that can withstand these harsh conditions. A recent study published in the Journal of Agriculture and Food Research, led by Elvira Sari Dewi from the University of Göttingen and Universitas Malikussaleh, offers promising insights into the drought resilience of sorghum, a vital crop for climate change adaptation.
Sorghum, a staple crop in many tropical regions, is known for its ability to tolerate drought. However, not all sorghum cultivars are created equal. Dewi and her team set out to understand how different cultivars respond to drought stress, utilizing a high-throughput functional phenotyping platform to monitor growth and physiological characteristics.
The study focused on three tropical sorghum cultivars: Kuali, Numbu, and Samurai2. The results were striking. Under drought conditions, Kuali showed significant reductions in plant height and total tiller number, while Numbu and Samurai2 were more resilient. “We observed notable variations in cultivar response to water stress,” Dewi explained. “This emphasizes the importance of selecting sorghum cultivars according to examined drought response traits.”
The team also measured transpiration, the process by which water is absorbed by plant roots, moves through plants, and is released as water vapor through pores in leaves. Kuali, with its high transpiration under high soil water content, quickly declined after the point of physiological drought stress was reached, indicating a non-conserving water use behavior. In contrast, Numbu, with much lower transpiration under high soil water content, only reduced transpiration gradually beyond this point, making it a typical water conserver. Samurai2 was an intermediate between the two.
Upon re-irrigation, all cultivars re-increased transpiration rates, with Kuali showing the highest total number of tillers. However, yield analyses revealed that Numbu had the highest grain yield and water-use efficiency under drought, followed by Samurai2, while Kuali had the lowest for both traits, indicating its vulnerability to drought.
So, what does this mean for the future of sorghum farming and the energy sector? Sorghum is not just a food crop; it’s also a valuable source of bioenergy. The findings of this study could guide farmers and breeders in selecting and developing sorghum cultivars that are not only drought-resistant but also high-yielding and water-efficient. This could significantly impact the energy sector, where sorghum is used for biofuel production.
As Dewi puts it, “Our study provides valuable insights for climate change adaptation.” Indeed, as we face an increasingly uncertain climate future, understanding and leveraging the drought resilience of crops like sorghum could be a game-changer. The research, published in the Journal of Agriculture and Food Research (translated as “Journal of Agricultural and Food Research”), opens doors for further exploration and innovation in this field.