Although sorghum is drought resistant relative to other crops, drought can reduce sorghum yields. Sorghum sensitivity to drought stress is greater during reproductive stages than during the vegetative stage. Drought frequency and severity are expected to worsen with climate change.
A new study published in in silico Plants examines potential strategies for sorghum yield improvement across Argentina.
Using the crop simulation model, APSIM, Dr. Ana Carcedo and colleagues from Universidad Nacional de Rosario and Bayer Crop Science explored how the interaction between sowing date, genotype phenology, and water stress patterns affected grain yield to define management strategies that best suit region and seasonal conditions.
Sowing dates were classified as early, intermediate, and late (figure 1).
Diverse genotype phenology was represented by sorghum genotypes that reach maturity at different times: short, medium, and late.
Growing regions of Argentina have different seasonal patterns of water stress. The authors characterized three water stress patterns (or environmental types) based on their seasonal timing and severity: pre-flowering stress, low terminal stress, and grain-filling stress (figure 2).
Optimizing sowing date provides a drought escape strategy to reduce the impact of the different water stress patterns. Choosing the correct sowing date and genotype can increase yield by 5,049 kg ha-1 (see figure 3).
For a farmer, it is impossible to know which environmental types will be experienced each year. The typically must either choose high risk/high yield or a conservative strategy that reduces risk but cannot achieve the yield potential possible in favorable seasons. This work proposes a conservative strategy that can also increase yields.