Brachiaria
Encyclopedia
Brachiaria is a genus of grasses originating from savannas of eastern Africa. These grasses are widely used as livestock forage. This genus includes 97 species, which can be found in tropical and subtropical climates, in both hemispheres, mostly in Africa and the Americas1. These grasses are monocots that are in the family Poaceae
Some species of Brachiaria were probably first introduced unintentionally to the Americas in the colonial period, from slave ships. More recently B. decumbens was introduced in 1952 into Brazil and B. ruziziensis in the 1960’s in Brazil as well. Brachiaria is the most widely used tropical grass in Central and South America, about 40 million hectares in Brazil alone
The most problematic pest the Brachiaria faces is the spittlebug , which is a known pest of the tropics. They also are prey to leaf-cutter ants and mound-building termites. There are a few fungal and viral diseases that Brachiaria face as well but the problem is that chemical control is not an option. Therefore disease-resistant cultivars need to be developed as a low-cost alternative
, leading different authors to exchange species between the two genera, supporting a growing idea that Brachiaria evolved from Panicum. There has also been some taxonomic confusion with this genera and Urochloa
. A recent phylogenetic analysis concluded that Brachiaria and Urochloa are a monophyletic group (along with Eriochloa and Melinis) and that further molecular and morphological work is needed to establish clear relationships.
These are annual or perennial grasses, most having rhizomes absent. The inflorescence
has panicle
branches composed of racemes and the entire plant usually gets no higher than 1 m. The flowers are fleshy with 3 anthers and the plants are bisexual. Some members of the genus have a prominent vein in the center of the leaf whereas others do not. Brachiaria are C4 plants which allows them to tolerate drier conditions and more light exposure than many other plants.
In North America, the native Brachiaria platyphylla (broadleaf signalgrass, an important agricultural pest) grows after heavy rains and then reproduces prodigiously and quickly.
Wide expanses of the tropics have been converted to Brachiaria pasture in order to support livestock, especially the Neotropics. In Brazil 80 million hectares of native habitat have been converted to Brachiaria pasture, using exotic species from Africa. This directly contributes to habitat loss and degradation, the leading global driver of the current global extinction crisis.
Besides direct loss of habitat through land conversion, introduced Brachiaria can degrade habitat my competing with native species. In North Australia, the exotic Brachiaria decumbens competes with the native tree Alphitonia petriei
by inhibiting the growth of seedlings, frustrating the conversion of old pastureland to natural forest. In the Paragominas region of Brazil, however, where much of the native forest has been replaced with Brachiaria and other exotic forage grasses, native forest naturally outcompetes the exotc pastureland and ranchers struggle to maintain pasture cover. Native species may also utilize exotic Brachiaria as a food resource. In the caatinga
of Brazil the native rodent Kerodon rupestris uses the exotic Brachiaria mutica as a food resource.
There has also been some research done showing that Brachiaria inhibits nitrification. This could be an amazing find since this it’s the most widely grown grass in South America on the same land as cattle. The cattle can eat this highly nutritious grass and it helps to keep down nitrous oxide (a greenhouse grass) levels in the atmosphere.
In Central America
, Mexico
has in the recent decades made great strides to improve their Brachiaria cultivar economy Mexico
has the highest volume of marketed seed, which has greatly improved their milk and beef industry. Other Central American countries have also reached high volumes of seed sold and area planted. The annual growth rate of seed sales was very high during the study period, reaching 32% in Mexico
, 62% in Honduras
, 45% in Nicaragua
, 39% in Costa Rica
, and 54% in Panama
. The area planted with Brachiaria species during this period totaled 6.5% of the total surface of permanent grasses in Mexico, 12.5% in Honduras, 1.0% in Nicaragua
, 18.7% in Costa Rica
, and 0.1% in Panama
.
Some species of Brachiaria were probably first introduced unintentionally to the Americas in the colonial period, from slave ships. More recently B. decumbens was introduced in 1952 into Brazil and B. ruziziensis in the 1960’s in Brazil as well. Brachiaria is the most widely used tropical grass in Central and South America, about 40 million hectares in Brazil alone
The most problematic pest the Brachiaria faces is the spittlebug , which is a known pest of the tropics. They also are prey to leaf-cutter ants and mound-building termites. There are a few fungal and viral diseases that Brachiaria face as well but the problem is that chemical control is not an option. Therefore disease-resistant cultivars need to be developed as a low-cost alternative
Biology
This genus was recognized over a hundred years ago and surprising for a large genus has not been divided. This could be due to the confusion with PanicumPanicum
Panicum is a large genus of about 450 species of grasses native throughout the tropical regions of the world, with a few species extending into the northern temperate zone...
, leading different authors to exchange species between the two genera, supporting a growing idea that Brachiaria evolved from Panicum. There has also been some taxonomic confusion with this genera and Urochloa
Urochloa
Urochloa is a genus of grass in the Poaceae family.-External links:*...
. A recent phylogenetic analysis concluded that Brachiaria and Urochloa are a monophyletic group (along with Eriochloa and Melinis) and that further molecular and morphological work is needed to establish clear relationships.
These are annual or perennial grasses, most having rhizomes absent. The inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
has panicle
Panicle
A panicle is a compound raceme, a loose, much-branched indeterminate inflorescence with pedicellate flowers attached along the secondary branches; in other words, a branched cluster of flowers in which the branches are racemes....
branches composed of racemes and the entire plant usually gets no higher than 1 m. The flowers are fleshy with 3 anthers and the plants are bisexual. Some members of the genus have a prominent vein in the center of the leaf whereas others do not. Brachiaria are C4 plants which allows them to tolerate drier conditions and more light exposure than many other plants.
Ecology and Conservation
To date, relatively few ecological or natural history investigations of Brachiaria in either the native or introduced range have been completed. Brachiaria can grow in environments from swamps to light forest shade to semi desert, but generally do best in savannas and other open tropical ecosystems such as in East Africa1. In Angola, Brachiaria brizantha does especially well on termite mounds and along the ecotone between grasslands and woodlands. In the Kora National Reserve in Kenya, Brachiaria dominates the ground layer along with Aristida. In India, the native Brachiaria ramosa is an important food source for the Indian Ring Dove, Streptopelia decaocto and Brachiaria species serve as forage for other herbivores within its native range.In North America, the native Brachiaria platyphylla (broadleaf signalgrass, an important agricultural pest) grows after heavy rains and then reproduces prodigiously and quickly.
Wide expanses of the tropics have been converted to Brachiaria pasture in order to support livestock, especially the Neotropics. In Brazil 80 million hectares of native habitat have been converted to Brachiaria pasture, using exotic species from Africa. This directly contributes to habitat loss and degradation, the leading global driver of the current global extinction crisis.
Besides direct loss of habitat through land conversion, introduced Brachiaria can degrade habitat my competing with native species. In North Australia, the exotic Brachiaria decumbens competes with the native tree Alphitonia petriei
Alphitonia petriei
Alphitonia petriei known as the White Ash is a rainforest tree in the Buckthorn family. It grows in eastern and northern Australia. Other common names include Red Ash, White-leaf, Pink Almond and Pink Ash. It was originally collected from the Johnston River near Kuranda, and named in 1925 by K.W....
by inhibiting the growth of seedlings, frustrating the conversion of old pastureland to natural forest. In the Paragominas region of Brazil, however, where much of the native forest has been replaced with Brachiaria and other exotic forage grasses, native forest naturally outcompetes the exotc pastureland and ranchers struggle to maintain pasture cover. Native species may also utilize exotic Brachiaria as a food resource. In the caatinga
Caatinga
Caatinga is a type of vegetation, and an ecoregion characterized by this vegetation in the northeastern part of Brazil. The name "Caatinga" is a Tupi word meaning "white forest" or "white vegetation"...
of Brazil the native rodent Kerodon rupestris uses the exotic Brachiaria mutica as a food resource.
There has also been some research done showing that Brachiaria inhibits nitrification. This could be an amazing find since this it’s the most widely grown grass in South America on the same land as cattle. The cattle can eat this highly nutritious grass and it helps to keep down nitrous oxide (a greenhouse grass) levels in the atmosphere.
Human Use
Brachiaria is the single most important foraging grass for pastures in the tropics. Brachiaria is indigenous to African Savannas, but can be found throughout the world in the tropical ecoregions. Brachiaria cultivars have impacted the economy of various countries found in the tropics because of its ability to grow in infertile soil with high acidity levels. One of the best attributes to Brachiaria is that it can grow so well in low-fertility acid soils and still be able to produce highly nutritious forage for many ruminants. In the past 25-30 years Brachiaria cultivation and export has become a major component of sown pastures. In the America’s, Brasil represents the leading user and producer of Brachiaria seeds.In Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
has in the recent decades made great strides to improve their Brachiaria cultivar economy Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
has the highest volume of marketed seed, which has greatly improved their milk and beef industry. Other Central American countries have also reached high volumes of seed sold and area planted. The annual growth rate of seed sales was very high during the study period, reaching 32% in Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, 62% in Honduras
Honduras
Honduras is a republic in Central America. It was previously known as Spanish Honduras to differentiate it from British Honduras, which became the modern-day state of Belize...
, 45% in Nicaragua
Nicaragua
Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...
, 39% in Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
, and 54% in Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
. The area planted with Brachiaria species during this period totaled 6.5% of the total surface of permanent grasses in Mexico, 12.5% in Honduras, 1.0% in Nicaragua
Nicaragua
Nicaragua is the largest country in the Central American American isthmus, bordered by Honduras to the north and Costa Rica to the south. The country is situated between 11 and 14 degrees north of the Equator in the Northern Hemisphere, which places it entirely within the tropics. The Pacific Ocean...
, 18.7% in Costa Rica
Costa Rica
Costa Rica , officially the Republic of Costa Rica is a multilingual, multiethnic and multicultural country in Central America, bordered by Nicaragua to the north, Panama to the southeast, the Pacific Ocean to the west and the Caribbean Sea to the east....
, and 0.1% in Panama
Panama
Panama , officially the Republic of Panama , is the southernmost country of Central America. Situated on the isthmus connecting North and South America, it is bordered by Costa Rica to the northwest, Colombia to the southeast, the Caribbean Sea to the north and the Pacific Ocean to the south. The...
.