Combining Ability in Mixtures of Prairie Grass and Clovers

Miguel Jacinto Arturi,Oscar Ansín,Mónica Beatriz Aulicino,Rodolfo Signorio,Gustavo Gallinger

doi:10.4236/ajps.2012.310163

Miguel Jacinto Arturi, Oscar Ansín + Show 3 more

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https://doi.org/10.4236/ajps.2012.310163

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Abstract

Our objective was to evaluate the combining ability among cultivars of forage species, commonly sown in temperate regions of Argentina using a short rotation system. Three genetically diverse cultivars of prairie brome grass (Bromus catharticus, cv Copetona, cv ?andu and cv Tango), a white clover cultivar (Trifolium repens, cv Lucero) and a red clover cultivar (T. pratense, cv Tropero) were evaluated. A randomized complete block design experiment was established in 2005. The treatments included five monocultures and ten binary mixtures. The experiment was harvested 6 times over an 18-month period. Cumulative dry matter yield (kg?ha–1) was calculated as the sum of the six individual harvests. Diallel analysis provided estimates of the general combining ability (GCA) and specific combining ability (SCA). Red clover in monoculture and mixtures produced the highest yields, with significant positive GCA effects (P P P P < 0.01). Given the short-term nature of this study, we must limit our inference to short-term pastures (<2 years). Under these conditions, red clover had the best combination with prairie brome grass.

Highlights

Sowing grass/legumes mixtures, as pasture for livestock, is a common practice in the temperate regions including most of the renovated prairies in the Argentinean pampas
Grass/grass mixtures and the legume/legume mixture showed non-significant specific combining ability (SCA) effects, while the grass/legume mixtures generally had higher yield than either component sown as a monoculture (P < 0.01)
The aim of this study is to evaluate the combining ability among cultivars of three species recommended for agricultural soils in the valley of the Salado river, prairie brome grass (Bromus catharticus Vahl.) and two legumes, white clover (Trifolium repens L.) and red clover (T. pratense L.)

Summary

Introduction

Sowing grass/legumes mixtures, as pasture for livestock, is a common practice in the temperate regions including most of the renovated prairies in the Argentinean pampas. Acceptance of these forage mixtures is based on the apparent advantages offered by the association of different genotypes or species that influence the performance temporal stability of yield and forage quality [1,2,3,4]. The yield of grass/legume mixtures is more stable under changing environmental conditions than monocultures. This results in higher mean biomass production in comparison to their components grown in monoculture. Biomass yields in mixtures are rarely lower than the poorer component [1]

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