Sustained improvement in tolerance to water deficit accompanies maize yield increase in temperate environments. Issue 6 (10th September 2022)

• Record Type: Journal Article
• Authors: Messina, Carlos; Ciampitti, Ignacio Antonio; Berning, Dan; Bubeck, Dave; Hammer, Graeme; Cooper, Mark
• Is Part Of: Crop science. Volume 62:Issue 6(2022)
• Page Start: 2138
• Page End: 2150
• Publication Date: 2022-09-10
• Subjects: Crop science -- Periodicals; Cultures -- Périodiques; Cultures de plein champ -- Périodiques; Crop science; Nutzpflanzen; Zeitschrift; Pflanzenbau; Periodicals; 633
• DOI: 10.1002/csc2.20781
• Languages: English
• ISSNs: 0011-183X

Abstract

Abstract: Studies at a regional scale suggest that although maize ( Zea mays L.) yield increased substantially, sensitivity to water deficit also increased concurrently with crop improvement. This study assessed changes in yield and yield stability after two decades of breeding by evaluating two cohorts of hybrids released by the AQUAmax program and comparing them to a non‐AQUAmax control. Studies were conducted in 2019 and 2020 seasons at four sites under well‐watered, moderate and severe stress conditions. Plant densities varied from 2.5 to 12.5 pl m−2. AQUAmax hybrids yielded more than non‐AQUAmax hybrids under water deficit conditions with the magnitude of the difference dependent on plant density. The sensitivity in yield across environments with a wide range of total crop evapotranspiration (350–800 mm) was lower for AQUAmax than non‐AQUAmax, so both yield and yield under stress conditions (yield stability), were enhanced for AQUAmax hybrids. The median differences between observed yields and the 80% quantile yield–evapotranspiration front were 379 for AQUAmax and 427 g m −2 for non‐AQUAmax hybrids. We conclude that deliberate selection of hybrids for yield performance under water deficit underpinned the sustained improvement in yield stability after two decades of drought breeding. Future research should focus on understanding the root causes for the suboptimal utilization of drought tolerant maize for the diversity of environments at a regional scale. Core Ideas: Yield improvement for drought is critical to enable a circular bioeconomy. Maize susceptibility to drought at regional scale is increasing with crop improvement. Genotype × management technology (G×M‐tech) is not the root cause of the higher instability. Socioeconomic factors and policy may underpin suboptimal use of G×M‐tech at regional scale.