Mitigate the effect of high temperatures on maize productivity

Executive Summary

Maize is one of the main sources of food for a high proportion of the region's population. Climate change will cause increases in temperatures that can negatively affect maize productivity in Latin America. Yield sensitivity to temperature (alone or associated with water or nutrient stress) is generally much higher if stress occurs during the period around flowering (which determines the number of grains per plant) or during the filling of the grains (which affects the final weight of the grains). However, the physiological causes that generate these effects on productivity have not been clearly elucidated, nor determined the genotypic variability that could be useful in this context in breeding programs.

The general objective of the project was to identify genetic and environmental factors of the susceptibility of maize productivity to high temperatures that can be useful both in genetic improvement and in the design of agronomic practices. Specifically:

1. elucidate the physiological origin of the effects of high temperatures on maize productivity;
2. determine the variability of the maize response to high temperatures;
3. quantify the effects of nitrogen fertilization and the application of an ethylene inhibitor in reducing susceptibility to high temperatures;
4. disseminate the scientific results to farmers and breeders of private companies in the region, as well as to the scientific community in general.

The technological solution

The high temperatures resulting from climate change can negatively affect maize production. The project contributed to improving the understanding of the effects of high temperatures on the phenological stages of cultivation and productivity, highlighting the importance of the effects during flowering and therefore on the number of grains produced per plant.

It also contributed to identify progenitors that can be used as potential donors of tolerance and the molecular markers that were significantly associated with the best behavior of maize against stress.

Likewise, it identified the importance of regulating nitrogen fertilization, since an excess could exacerbate the effects of high temperatures, while a deficiency would generate yield losses obtainable in the event of severe thermal stresses.

Results

Beneficiaries

The main direct beneficiaries were the hundreds of researchers, professionals, and students who participated in project activities, including the numerous courses, talks, conferences, and scientific publications.

Thousands of maize producers could benefit indirectly through the incorporation of the knowledge generated in the project in genetic and agronomic improvement programs in the countries.

Sustainable Development Goals

Main donors