ABSTRACT
In forage-plants breeding, the selection of superior genotypes has been undertaken through successive harvests in previously established intervals. However, this process involves many steps, the evaluation of many traits, and a great spending with costs and labor. Thus the estimate of the repeatability is essential in improvement of perennials, it allows predicting genotypic value of the individual, the minimum number of evaluations in the selection of genotypes and minimizes resources and time in the selection of promising individuals. The objective of this study was to estimate the repeatability coefficient for morphological traits in elephant grass and determine the number of evaluations needed for phenotypic selection more efficient. The experimental randomized block design with 53 genotypes and two replications. The repeatability coefficients were estimated for variables plant height, number of tillers, stem diameter and dry matter yield, using the methods of Anova, Principal Components and Structural Analysis. We observed significant differences between genotypes (P <0.01) for all variables. The main components provide larger estimates of repeatability when compared to other methods. Estimates of the repeatability coefficients are of high magnitude average for the variables plant height (0.44) number of tillers (0.44) and stem diameter (0.63) and low magnitude for dry matter production (0.27). The Principal Components method requires five, five, two and eleven measurements for plant height, number of tillers, stem diameter and dry matter yield, respectively, with 80% reliability.
No melhoramento de plantas forrageiras, a seleção de genótipos superiores tem sido realizada mediante a realização de cortes sucessivos em intervalos previamente estabelecidos. Entretanto este processo envolve muitas etapas, avaliação de muitos caracteres e um grande dispêndio de custos e mão-de-obra. Assim, a estimativa da repetibilidade é essencial no melhoramento de plantas perenes, pois permite predizer o valor genotípico do indivíduo, o número mínimo de avaliações na seleção de genótipos e minimiza recursos e tempo na seleção de indivíduos promissores. O objetivo deste trabalho foi obter estimativas do coeficiente de repetibilidade para caracteres morfoagronômicos em capim-elefante e determinar o número de avaliações necessárias para seleção fenotípica com maior eficiência. Utilizou-se delineamento experimental de blocos casualizados com 53 genótipos e duas repetições. Foram estimados os coeficientes de repetibilidade para as variáveis altura de plantas (ALT), número de perfilhos (NP), diâmetro de colmo (DC) e produtividade de matéria seca (PMS), utilizando-se os métodos da Anova, Componentes principais e Análise estrutural. Observaram-se diferenças significativas entre os genótipos (p<0,01) para todas as variáveis avaliadas. Os componentes principais proporcionam maiores estimativas de repetibilidade em relação aos demais métodos. As estimativas dos coeficientes de repetibilidade são de média a alta magnitude, para as variáveis ALT, NP e DC e de baixa magnitude para PMS. Com base no método dos Componentes Principais são necessárias cinco, cinco, duas e onze medidas para altura da planta, número de perfilhos, diâmetro do caule e rendimento de matéria seca, respectivamente, com 80% de confiabilidade.
Subject(s)
PennisetumABSTRACT
Objetivou-se avaliar o potencial de silagens de ramas de diferentes clones de batata-doce para alimentação animal. O trabalho foi realizado na Fazenda Forquilha localizada no Distrito de Batatal, município de Diamantina MG, no período de 23/12/2007 a 23/06/2008. O experimento foi conduzido no esquema de parcelas subdivididas em delineamento de blocos completos casualizados. Foram avaliadas a produtividade de matéria verde e matéria seca das ramas e a composição químico-bromatológica, além do perfil fermentativo de suas silagens, em três idades de colheita (120, 150 e 180 dias), em oito clones de batata doce. A produtividade de matéria seca não variou com a época de colheita das ramas, obtendo-se média de 6,01t ha-1. Os teores de matéria seca nas ramas aumentaram com o ciclo da cultura, verificando-se teores médios de 11,94; 12,16 e 19,62 por cento, aos 120, 150 e 180 dias após o corte, respectivamente. As silagens das ramas de batata-doce apresentaram altos teores protéicos e energéticos e adequado perfil fermentativo, portanto, apresentam potencial para utilização na alimentação animal, independentemente dos clones.
The objective was to evaluate the potential of silage derived from different clones of sweet potato for animal feed. The study was conducted at Forquilha Farm located in Batatal district, MG Diamantina in the period from 23/12/2007 to 23/06/2008. The experiment was conducted in split plot design in a randomized complete block. It was evaluated the green and dry matter yield, the chemical composition and the fermentative profile of silage harvested on three dates (days 120, 150 and 180), of eight clones of sweet potato. The dry matter yield did not vary according to the harvest time of the branches, resulting in an average of 6.01t ha-1. The dry matter content in the stems increased with the growth cycle, and there are average levels of 11.94, 12.16 and 19.62 percent on days 120, 150 and 180 after cutting, respectively. The raw potato silage showed high protein content and adequate energy fermentation and therefore, potential for use in animal feed, regardless of clones.
ABSTRACT
Five medicinal plants viz. Abelmoschatus moschatus Linn., Clitoria ternatea L., Plumbago zeylanica L., Psorolea corylifolia L. and Withania sominifera L. were grown in a polypot experiment in five soils representing coal mine soil, copper mine soil, fly ash, skeletal soil and forest soil with and without mycorrhizal inoculations in a completely randomized block design. Dry matter yield and mycorrhizal root colonization of plants varied both in uninoculated and inoculated conditions. The forest soil rendered highest dry matter due to higher yield of A. moschatus, P. zeylanica and P. corylifolia while fly ash showed lowest dry matter without any inoculants. P. cernatea were best in coal mine soil and W. sominifera in copper mine soil without mycorrhizal inoculation. The mycorrhiza was found to enhance the dry matter yield. This contributed minimum 0.19% to maximum up to 422.0% in different soils as compared to uninoculated plants. The mycorrhizal dependency was noticed maximum in plants grown in fly ash followed by coal mine soil, copper mine soil, skeletal soil and forest soil. The mycorrhizal response was increased maximum in W. sominifera due to survival in fly ash after inoculation followed by P. corylifolia and P. cernatea. Percent root colonization in inoculated plant was increased minimum of 1.10 fold to maximum of 12.0 folds in comparison to un-inoculated plants .The native mycorrhiza fungi were also observed to colonize 4.0 to 32.0% roots in plants under study. This study suggests that mycorrhizal inoculation increased the dry matter yield of medicinal plants in all soils under study. It also helps in survival of W. sominifera in fly ash.