Development of Waterlogging-Tolerant Brachiaria Genotypes for Humid Areas of Latin America to Increase Cattle Production and to Adapt Grazing Systems to Climate Variability and Change.

Livestock production in humid areas of Latin America utilizes different species of perennial Brachiaria forage grasses. Brachiaria pastures may be exposed to extreme weather events associated with climate variability and change. These could cause seasonal waterlogging conditions that affect pasture productivity and persistence leading to pasture degradation and reduced meat and milk production. In many humid zones, livestock producers use B. humidicola cv. Tully because of its high tolerance to seasonal waterlogging. However, a major limitation of this cultivar is its low forage quality that limits animal performance. CIAT has an on-going breeding program on B. decumbens x B. brizantha x B. ruziziensis that developed two commercial hybrids (Mulato and Mulato II) that have a number of positive attributes, but are not tolerant to waterlogging. A regional collaborative research project is in progress to develop Brachiaria genotypes that combine several desirable traits including improved waterlogging tolerance, pest and disease resistance, good forage quality, and high forage and seed production. The main objective of this work is to evaluate and select Brachiaria hybrids and accessions of B. humidicola with improved tolerance to waterlogging conditions. Significant progress has been made in the project to: a) estimate areas of Latin America with poorly drained soils and target improved Brachiaria genotypes to suitable areas; b) use climate models to develop scenarios for the years 2020 and 2050; c) define morpho-physiological responses that explain the differential tolerance to waterlogged conditions among contrasting Brachiaria genotypes; d) screen improved Brachiaria hybrids and B. humidicola germplasm accessions to identify genotypes with waterlogging tolerance and productivity superior to commercial cultivars; and e) with participation of farmers, evaluate a set of promising genotypes for their performance under waterlogged field conditions in representative sites in Colombia, Nicaragua and Panama. This work is partially supported from the funds of Fontagro.