F. D. Fernandes

Forage yield and nutritive value of Panicum maximum genotypes in the Brazilian savannah

The narrow genetic variability of grasslands and the incidence of new biotic and abiotic stresses have motivated the selection of new Panicum maximum genotypes for use as forage for beef cattle in the Brazilian savannah. This study aimed to evaluate forage yield and nutritive value of P. maximum genotypes including 14 accessions (PM30 to PM43), four intraspe- cifi c hybrids (PM44 to PM47) and six cultivars (Aruana, Massai, Milenio, Mombaca, Tanzania and Vencedor), examining 24 genotypes over two years (2003 and 2004). Milenio cultivar was the genotype with the highest dry matter yield (DMY) in both years (18.4 t ha -1 and 20.9 t ha -1 , respectively) although it presented a high proportion of stems (~ 30 %). Genotypes that showed higher Leaf DMY in both years were the accession PM34 (14.7 t ha -1 ) and the hybrid PM46 (14.0 t ha -1 ), while Mombaca and Tanzania yielded 12.5 and 11.0 t ha -1 , respectively. Leaf organic mat- ter digestibility and leaf DMY for PM40 and PM46 genotypes exceeded the mean (> 656 g kg -1

BRS Japonesa: new sweet cassava cultivar for the Distrito Federal region

The sweet cassava cultivar BRS Japonesa was selected by the cassava breeding program of Embrapa Cerrados in 25 participatory evaluations conducted in the region of the Distrito Federal, Brazil. The cultivar was well-accepted by producers, and the probability of being ranked among the top four cultivars is 80 %.

Avaliação de genótipos de mandioca industriais em área de Cerrado do Noroeste de Minas Gerais

A avaliacao agronomica de cultivares e passo inicial para a determinacao do potencial de cultivo de uma cultura em determinado local. Entretanto, ainda nao foram desenvolvidos estudos sistematicos visando a determinacao do potencial produtivo de diferentes genotipos de mandioca para industria, na regiao de Unai, Minas Gerais. Por isso, o objetivo deste estudo foi avaliar, por duas safras, 12 genotipos-elite de mandioca para industria de farinha e fecula, em area de Cerrado da Regiao Noroeste de Minas Gerais, no municipio de Unai. Os experimentos foram conduzidos entre novembro de 2010 e maio de 2012 (safra 2010/2012) e entre novembro de 2011 e maio de 2013 (safra 2011/2013), em area experimental da Escola Agricola de Unai. Aos 12 meses apos o plantio, nas duas safras, efetuou-se a poda da parte aerea, a 10 cm do solo, de todos os genotipos. Aos 18 meses apos o plantio dos experimentos, os genotipos foram avaliados quanto aos caracteres peso da parte aerea, produtividade de raizes, percentagem de amido nas raizes e foi estimado o rendimento de amido. Os dados foram submetidos a analise de variância individual e conjunta e ao teste de agrupamento de medias. Os resultados revelaram que os genotipos diferiram quanto aos caracteres avaliados, sendo que todos apresentaram caracteristicas com potencial para cultivo, nas condicoes locais de avaliacao, como elevada produtividades de raizes, elevado peso da parte aerea, elevados teores de amido nas raizes e elevado rendimento de amido, com destaque para o acesso BGMC 996.

Forage yield and nutritive value of Arachis spp. genotypes in the Brazilian savanna.

Forage yield, nutritive value, ground cover and mineral concentration of 10 genotypes of Arachis spp. were evaluated over 3 years in Planaltina, Federal District, Brazil. Experimental plots were arranged in a randomized complete block design with 4 replications. Treatments were 5 genotypes of A. pintoi (accessions 2, 4, 5, 6 and 8), 2 genotypes of A. repens (accessions 1 and 7), 1 hybrid A. pintoi × A. repens (accession 3) and 2 A. pintoi cultivars, BRS Mandobi and Belmonte. All genotypes established well and achieved good ground cover in the first year. Cultivar Belmonte and accessions 2 and 4 produced the highest DM yields (means of 8.8, 8.5 and 8.8 t DM/ha/yr, respectively) throughout, while cv. BRS Mandobi and accession 6 were the worst (5.7 and 5.6 t DM/ha/yr). Most genotypes maintained ground cover above 80% throughout the study but cv. BRS Mandobi plus accessions 6 and 8 had declined to 60% or less by the third year. Mean crude protein concentration overall was 166 g/kg with a range of 154‒182 g/kg among genotypes. There was no major genotypic variation in mineral concentrations, which in all cases were considered marginal to adequate for tropical forage legumes. In conclusion, genotypes 2 and 4 (accessions BRA-039799 and BRA-039187, respectively) of A. pintoi are considered the most promising forage peanut options under the edaphoclimatic conditions of the experimental site. More effort is needed to improve seed set in these accessions to increase adoption by farmers. Their persistence under grazing and impact on production should also be demonstrated. Keywords : Arachis pintoi , Arachis repens , crude protein, digestibility, minerals.