Etnobotânica e diversidade genética de mandioca (Manihot esculenta Crantz.): a manutenção da agrobiodiversidade em comunidades tradicionais de Jangada, Mato Grosso, Brasil
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Data
2017-11-06
Autores
Oler, Juliana Rodrigues Larrosa [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Sabe-se que os agricultores de pequena escala que praticam agricultura de modo tradicional desempenham um importante papel na manutenção da agrobiodiversidade, podendo complementar o trabalho de conservação ex situ. Um dos cultivos mais presentes na agricultura tradicional tropical é a mandioca (Manihot esculenta Crantz.), base alimentar de mais de 800 milhões de pessoas no mundo. No Brasil, encontra-se elevada diversidade intraespecífica da referida tuberosa, sobretudo entre os agricultores da Baixada Cuiabana, Mato Grosso, que ainda praticam agricultura nos moldes tradicionais por meio de técnicas que não apenas mantêm, mas também amplificam essa diversidade. O presente estudo teve como objetivo caracterizar a dinâmica de cultivo das variedades locais de mandioca das comunidades tradicionais contíguas Mutum (Mt), Vaquejador (Vq), Ribeirão das Pedras Acima (Ra) e Quilombo (Qb), localizadas no município de Jangada-MT e analisar a influência dos aspectos socioeconômicos, culturais e genéticos na manutenção da agrobiodiversidade local, bem como analisar as relações entre as comunidades estudadas e suas influências sobre o manejo da agrobiodiversidade. Os capítulos que compõem este trabalho consistem em: 1) Apresentação da problemática, área de estudo, métodos e análises utilizados; 2) Caracterização socioeconômica das comunidades estudadas e dos agricultores; 3) Descrição dos espaços de cultivo, técnicas de manejo e produção de farinha de mandioca; e 4) Levantamento etnobotânico e análise genética das variedades de mandioca cultivadas. Em linhas gerais, o perfil dos agricultores foi semelhante, sendo a atividade agrícola praticada principalmente por homens com idade mediana de 56 anos. Quanto à manutenção dos jovens no campo, a comunidade Mt foi a que apresentou maior saída de jovens da zona rural (63,9 %), enquanto que Ra exibiu a maior quantidade de novas unidades familiares no mesmo local (64,3 %). Falta de infraestrutura, de acesso à educação e a serviços de saúde, assim como a busca por melhores oportunidades profissionais destacaram-se entre os motivos para que os jovens deixassem as comunidades. A agricultura era praticada em quintais e roças nas quatro comunidades. O modo de fazer agricultura foi similar em todas elas, mesclando técnicas tradicionais e modernas, sendo que a mandioca constituía uma importante espécie para alimentação. A principal dificuldade para o cultivo da mandioca foi a escassez de mão de obra e de assistência técnica. A manufatura de farinha de mandioca era mais importante para as comunidades Ra e Vq. Os agricultores citaram a presença do atravessador como o maior entrave para a comercialização da farinha produzida. Foram catalogadas 31 variedades locais, sendo Mt a comunidade mais diversificada (H’ = 2,64). Elevada diversidade genética também foi observada, evidenciando o potencial das comunidades como mantenedoras da agrobiodiversidade. A rede de circulação de propágulos mostrou-se complexa e pode ser responsável pela semelhança genética das comunidades mais próximas entre si geograficamente. A existência de outras comunidades e até cidades abarcadas pela rede de circulação de propágulos indica a necessidade de uma abordagem regional em futuros estudos para melhor compreensão da dinâmica de conservação da agrobiodiversidade.
Small-scale farmers who perform agriculture in a traditional manner are known to play an important role in maintaining agrobiodiversity and, therefore, they may complement ex situ conservation work. Cassava (Manihot esculenta Crantz.) is one of the most important crops in traditional tropical agriculture, being considered as staple food for more than 800 million people in the world. There is a high intraspecific diversity in Brazil, especially among farmers located in the region of Baixada Cuiabana, Mato Grosso, which still cultivates it in a traditional way, using techniques that contribute not only to maintain but also to expand the diversity. Thus, this study aimed to characterize the dynamics of cultivation of local cassava varieties, given its relevance to small scale farmers, of four contiguous traditional communities located in the municipality of Jangada, State of Mato Grosso, Brazil; Mutum (Mt), Vaquejador (Vq), Ribeirão das Pedras Acima (Ra), and Quilombo (Qb); and it also aimed to analyze the influence of socioeconomic, cultural and genetic aspects in the maintenance of agrobiodiversity, as well as the relations between studied communities and their influences on the agrobiodiversity management. The chapters of this work consist of: 1) Problem presentation, study area, methods and adopted analysis; 2) Socioeconomic characterization of studied communities and farmers; 3) Description of crop spaces, management techniques and production of cassava flour; and 4) Ethnobotanical survey and genetic analysis of cultivated cassava varieties. In general, the farmers profile was similar, with agricultural activity being performed mainly by men with median age of 56 years. Regarding the maintenance of the youth in the countryside, Mt community presented the largest rural youth drop out (63.9 %), as Ra community showed the largest number of new local family units (64.3 %). The deficiency in infrastructure as well as in education and health services access, and the seek for greater job opportunities composed the main reasons why young people would leave the countryside. In the four communities, agriculture was being practiced in backyards and gardens. The way they used to perform it was similar in all of them, mixing traditional and modern techniques, with cassava being a fundamental species as for feeding. The main difficulty as to cassava cultivation was the lack of both labor force and technical assistance and its flour production was more relevant for Ra and Vq communities. Farmers mentioned the middleman presence as the major obstacle in marketing the produced flour. Thirty-one local varieties were surveyed, with Mt community being the most diversified (H’ = 2.64). The communities also presented high genetic diversity, revealing their potential as agrobiodiversity maintainers. Propagules circulation network has proved to be complex and may be responsible for the genetic resemblance of nearby communities. The existence of other communities and even towns within the propagules circulation network indicates the need for a regional approach in future studies in order to improve the comprehension about the dynamics of agrobiodiversity conservation.
Small-scale farmers who perform agriculture in a traditional manner are known to play an important role in maintaining agrobiodiversity and, therefore, they may complement ex situ conservation work. Cassava (Manihot esculenta Crantz.) is one of the most important crops in traditional tropical agriculture, being considered as staple food for more than 800 million people in the world. There is a high intraspecific diversity in Brazil, especially among farmers located in the region of Baixada Cuiabana, Mato Grosso, which still cultivates it in a traditional way, using techniques that contribute not only to maintain but also to expand the diversity. Thus, this study aimed to characterize the dynamics of cultivation of local cassava varieties, given its relevance to small scale farmers, of four contiguous traditional communities located in the municipality of Jangada, State of Mato Grosso, Brazil; Mutum (Mt), Vaquejador (Vq), Ribeirão das Pedras Acima (Ra), and Quilombo (Qb); and it also aimed to analyze the influence of socioeconomic, cultural and genetic aspects in the maintenance of agrobiodiversity, as well as the relations between studied communities and their influences on the agrobiodiversity management. The chapters of this work consist of: 1) Problem presentation, study area, methods and adopted analysis; 2) Socioeconomic characterization of studied communities and farmers; 3) Description of crop spaces, management techniques and production of cassava flour; and 4) Ethnobotanical survey and genetic analysis of cultivated cassava varieties. In general, the farmers profile was similar, with agricultural activity being performed mainly by men with median age of 56 years. Regarding the maintenance of the youth in the countryside, Mt community presented the largest rural youth drop out (63.9 %), as Ra community showed the largest number of new local family units (64.3 %). The deficiency in infrastructure as well as in education and health services access, and the seek for greater job opportunities composed the main reasons why young people would leave the countryside. In the four communities, agriculture was being practiced in backyards and gardens. The way they used to perform it was similar in all of them, mixing traditional and modern techniques, with cassava being a fundamental species as for feeding. The main difficulty as to cassava cultivation was the lack of both labor force and technical assistance and its flour production was more relevant for Ra and Vq communities. Farmers mentioned the middleman presence as the major obstacle in marketing the produced flour. Thirty-one local varieties were surveyed, with Mt community being the most diversified (H’ = 2.64). The communities also presented high genetic diversity, revealing their potential as agrobiodiversity maintainers. Propagules circulation network has proved to be complex and may be responsible for the genetic resemblance of nearby communities. The existence of other communities and even towns within the propagules circulation network indicates the need for a regional approach in future studies in order to improve the comprehension about the dynamics of agrobiodiversity conservation.
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Palavras-chave
Mandioca, Agricultura tradicional, Conservação on farm, Diversidade genética, Cassava, Traditional agriculture, On farm conservation, Genetic diversity