Avaliação da produtividade e valor nutritivo de acessos de Paspalum spp. em Botucatu - SP para uso como planta forrageira
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Data
2020-11-06
Autores
Gomes, Vinicius Carreteiro [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
É crescente a demanda por diversificação de forrageiras tropicais que possam contribuir para a redução das extensas áreas de monocultivo. O objetivo deste estudo foi caracterizar e possivelmente indicar para uma próxima fase do programa de melhoramento de forrageiras 25 acessos do gênero Paspalum que tiveram características desejáveis (e.g.; elevado valor nutritivo, alta capacidade produtiva). Os tratamentos corresponderam a frequência de corte representado por intervalos de 28 e 70 dias conforme as estações chuvosas e secas respectivamente de 2017 e 2018, totalizando 2 anos de avaliação. Os acessos foram alocados em unidades experimentais (parcelas de 2,5 m²) seguindo um delineamento de blocos completos casualizados, com 4 repetições. Cada parcela era representada por um acesso e composta por 5 plantas. O corte foi realizado a uma altura de 10 cm do solo como forma de padronização e a cada ciclo foram avaliados: indicativos agronômicos e indicativos do valor nutritivo. Dentre os acessos e as características avaliadas existe uma grande variabilidade genética e que sendo separados em 3 grupos elucida e ajuda programas de melhoramento a definir critérios para cruzamentos futuros, seleção e lançamento de novas cultivares. Os acessos de BGP-15, BGP-98, BGP-308 e BGP-298 (P. atratum) e BGP-341 (P. regnellii) despontam pelo seu potencial produtivo mesmo sendo estacionais e os acessos BGP-298 e BGP-308 podem ser indicados pela elevada relação lâmina foliar:colmo e grande porcentagem de folha. Os acessos BGP-341 e BGP-344 (P. regnellii) pela alta concentração de PB, os acessos BGP-15, BGP-98, BGP-308, BGP-298, BGP-93 e BGP-492 (P. atratum), BGP-205 (P. guenoarum) e BGP-6 (P. malacophyllum) pelo baixo teor de FDN e o BGP-293, BGP-6 (P. malacophyllum) pela maior DIVMS.
There is a growing demand for diversification of tropical forages that can contribute to the reduction of extensive monoculture areas. The objective of this study was to characterize and possibly indicate, for a next step of the forage breeding program, 25 accessions of Paspalum spp. genus that has a desirable characteristic (e.g., high nutritional value and high productive capacity). The treatments corresponded to the cutoff frequency represented by intervals of 28 and 70 days according to the rainy and dry seasons for 2017 and 2018, totaling 2 years of evaluation. The accesses were allocated in experimental units (plots of 2.5 m²) following a complete randomized block design, with 4 replications. Each plot was represented by an access and composed of 5 plants. The cut was made at a height of 10 cm from the ground and at each cycle were evaluated: agronomic indications and indicative of nutritional value. Among the accessions and the evaluated characteristics there is a great genetic variability and separated into 3 clusters, clarifies, and helps forage breeding programs to define criteria for future crosses, selection and launch of new cultivars. The accessions of BGP-15, BGP-98, BGP-308 and BGP-298 (P. atratum) and BGP-341 (P. regnellii) stand out for their productive potential even though they are seasonal and the accessions BGP-298 and BGP-308 can be indicated by the high leaf/stem ratio and large percentage of leaf. The accessions BGP-341 and BGP-344 (P. regnellii) due to the high concentration of crude protein, accessions BGP-15, BGP-98, BGP-308, BGP-298, BGP-93 and BGP-492 (P. atratum), BGP-205 (P. guenoarum) and BGP-6 (P. malacophyllum) for low neutral detergent insoluble fiber content and BGP-293, BGP-6 (P. malacophyllum) for the highest in vitro dry matter digestibility.
There is a growing demand for diversification of tropical forages that can contribute to the reduction of extensive monoculture areas. The objective of this study was to characterize and possibly indicate, for a next step of the forage breeding program, 25 accessions of Paspalum spp. genus that has a desirable characteristic (e.g., high nutritional value and high productive capacity). The treatments corresponded to the cutoff frequency represented by intervals of 28 and 70 days according to the rainy and dry seasons for 2017 and 2018, totaling 2 years of evaluation. The accesses were allocated in experimental units (plots of 2.5 m²) following a complete randomized block design, with 4 replications. Each plot was represented by an access and composed of 5 plants. The cut was made at a height of 10 cm from the ground and at each cycle were evaluated: agronomic indications and indicative of nutritional value. Among the accessions and the evaluated characteristics there is a great genetic variability and separated into 3 clusters, clarifies, and helps forage breeding programs to define criteria for future crosses, selection and launch of new cultivars. The accessions of BGP-15, BGP-98, BGP-308 and BGP-298 (P. atratum) and BGP-341 (P. regnellii) stand out for their productive potential even though they are seasonal and the accessions BGP-298 and BGP-308 can be indicated by the high leaf/stem ratio and large percentage of leaf. The accessions BGP-341 and BGP-344 (P. regnellii) due to the high concentration of crude protein, accessions BGP-15, BGP-98, BGP-308, BGP-298, BGP-93 and BGP-492 (P. atratum), BGP-205 (P. guenoarum) and BGP-6 (P. malacophyllum) for low neutral detergent insoluble fiber content and BGP-293, BGP-6 (P. malacophyllum) for the highest in vitro dry matter digestibility.
Descrição
Palavras-chave
Capacidade produtiva, Pastagem nativa, Variabilidade genética, Genetic variability, Productive capacity, Native pasture