Brachiaria genotypes adapted to poorly drained soils

Executive Summary

In Tropical America there are vast areas of poorly drained soils that are very important for the production of meat and milk. The Brachiarias occupy about 50% of the floodable areas in tropical pastures in Brazil; 60% of those areas in Bolivia, Peru and Ecuador; and significant proportions of those areas in other countries of the region. The most used cultivars have been B. decumbens cv. Basilisk, B. brizantha cv. Marandú and B. humidicola cv. Tully. The Marandú is the most used in the region, but it is susceptible to poor drainage, presenting symptoms of wilting and death. Tully is widely used in these regions for its high tolerance to poor drainage. However, it has low nutritional quality, limiting animal performance. 

Breeding of the Brachiaria genus at CIAT has focused on the development of hybrids of the B. decumbens, B. brizantha and B. ruziziensis complex and recently on hybrids of B. humidicola. They want to combine characteristics such as resistance to spittlebug and Rhizoctonia solani, with adaptation to abiotic factors (acid soils, drought), high nutritional quality, yield and seed quality. The objective of the project was to develop and evaluate accessions of B. humidicola and Brachiaria hybrids (B. decumbens x B. brizantha x B. ruziziensis) with greater tolerance to waterlogged soils and with good agronomic performance through the identification of tolerance mechanisms and areas suitable for use.

The strategy included: 1. Carry out a spatial analysis to quantify livestock areas in Tropical America with poorly drained soils; 2. Apply a method of selecting Brachiaria genotypes adapted to poorly drained soils; 3. Select Brachiaria hybrids and B. humidicola accessions adapted to poorly drained soils; and 4. Evaluate the selected genotypes with producers.

The technological solution

The project, through a spatial analysis using the databases of GBIF (Global Biodiversity Information Facility) and Genesys (Portal of global information on genetic resources –ex situ-), produced maps to estimate the flood areas in the tropical zone of Latin America and the Caribbean and with the use of global climate models, estimated the future expansion of flood areas in the different countries of the region due to climate change, and thus estimated the areas of potential use of Brachiarias for livestock, in areas not appropriate for cropping. 

Five Brachiarias genotypes were also identified that combined desirable adaptation characteristics to floodable soils with nutritional attributes for livestock feeding and the anatomical and morphological mechanisms that make them more tolerant to poorly drained soils. 

Results

Beneficiaries

The direct beneficiaries are the researchers and technicians from Colombia, Nicaragua and Panama who participated in project activities. Also, the hundreds of researchers and technicians who have accessed the results and knowledge generated in the project through publications and presentations made at national and international conferences. 
Indirect and potential beneficiaries would be the thousands of livestock producers who have flooded soils in their farms and who could use the accessions and hybrids of Brachiarias tested in the project.

Sustainable Development Goals

Main donors