Desempenho de cultivares de feijoeiro (Phaseolus vulgaris L.) em Rio Pomba, Minas Gerais, no sistema org?nico de produ??o, a partir da co-inocula??o das sementes com Rhizobium tropici e Azospirillum brasilense

• Ano de defesa: 2016
• Autor(a) principal: Louren?o, Fagner Jos? de Carvalho
• Orientador(a): Ribeiro, Raul de Lucena Duarte , Guerra, Jos? Guilherme Marinho
• Banca de defesa: Rumjanek, Norma Gouv?a, Fernandes, Maria do Carmo de Ara?jo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural do Rio de Janeiro
• Programa de Pós-Graduação: Programa de P?s-Gradua??o em Agricultura Org?nica
• Departamento: Instituto de Agronomia
• País: Brasil
• Palavras-chave em Português: Agroecologia; Feij?o; Gen?tipos; Inoculantes bacterianos
• Palavras-chave em Inglês: agroecology; bean; genotypes; bacterial inoculants
• Área do conhecimento CNPq: Agronomia
• Link de acesso: https://tede.ufrrj.br/jspui/handle/jspui/1330

A fild plot was carried out in Rio Pomba, MG state, dealing with beans (Phaseolus vulgaris L.) from March to May 2015. Six cultivars were compared under organic farming from seeds inoculated or not inoculated (= control) with commercial biological products based upon N2 fixing bacteria (Rhizobium tropici) and plant growth promoting bacteria (Azospirillum brasilense). Two of the cultivars, ?Ouro Vermelho? and ?BRSMG Madrep?rola?, are recommended and have been developed for Minas Gerais bean growing regions. They are both characterized by a high grain yield potential and belong to ?vermelho? and ?carioca? groups, respectively, which are of known preference by state consumers. On the other hand the cultivars ?Bola?, ?Kaboon?, ?Constanza?, and ?Manteig?o? represent introduced genotypes producing grains considered of special types on account of tegument color, size (= mass) and / or shape differing from the most commonly planted beans in Brazil. Such differential traits have been associated to an aggregate value because of their higher prices in the organic market of Brazilian southeast large cities. The study aimed at evaluating the introduced cultivars in comparison with the regional cultivars relating agronomic performance under organic farming as well as the respective response to seed inoculation with the cited bacterial species having a potential for contributing to beans organic management system by favoring crop yields. The research concept was based on the perspective of agrobiodiversity gains in organic farming units and on the possibility to improve farmer?s family income by means of expanding foods variety offered to consumers, specially focusing on beans, a major daily component of Brazilian?s diet due to its high nutritional quality. The experiment followed a randomized block design in a six x two factorial scheme with four replicates. Results referring data on marketable grain yields pointed out the viability of beans organic farming under Rio Pomba soil and weather conditions. The special grains introduced cultivars yields were close or, in certain cases, comparable to those of the two Minas Gerais recommended cultivars. The overall average of cultivars yields, independently of seed treatments, in which co-inoculation did not differ from the control (= non treated seeds), widely surpassed regional and national mean yields reported for the bean crop. The N2 stock ready to be utilized by the plants present in the soil of the experimented plant and a possible significant contribution fron biological fixation were able to fulfill crop requirements since no inputs have been made as nitrogen fertilizers. Root nodulation otherwise indicated the relevant contribution of local soil bacterial communities already stablished in the experimental plot and responsible for beneficial interactions with the bean plants. On the basis of the average between seed treatments the highest nodulation rates in terms of total number of nodules per root dry matter linked to the cultivars ?Ouro Vermelho? and ?BRSMG Madrep?rola? which also had the higher grain yields. Statistical analysis of the agronomic attributes considered in the study demonstrated significant differences among cultivars, including: number of pods per plant, number of grains per pod, and weight (= mass) of 100 grains (approx. 12% moisture). The first of such traits positively correlated with grain yield. Data also indicated that the number of grains per pod was inversely proportional to the 100 grains / mass. The last index (100 grains / mass weight) represented an estimative of the differences in grain sizes. With no exceptions, those introduced cultivars producing larger ? sized grains also revealed higher 100 grains mass values. The discarded levels of grains not reaching market standards again varied among cultivars and had influence on commercially suitable grain yields. This result leads to the need of adjusting bean organic farming in order to reduce yield losses.