Performance of Lotus corniculatus L. genotypes submitted to cutting interval: subsidies to a breeding program

Abstract

-The objective of this work was to evaluate the response of five birdsfoot trefoil populations (Lotus corniculatus L.), selected under severe and intense grazing (P38, P37, P9 and P3) or cutting (population Corte), one rhizomatous population from Morocco and two cultivars, São Gabriel (Brazil) and ARS 2620 (USA), to different cutting intervals (20 and 40 days). The trial was carried out in a greenhouse for 224 days. The plants were submitted to the treatments during four months, when it was made four and two cuttings for the 20 and 40 day intervals, respectively. In the following months, aerial part of the plants was totally removed and after 70 days of regrowth, evaluation of roots and aerial section were performed. Analysis of variance and multivariate analysis was performed, obtaining the Mahalanobis distance (Md), dendogram by UPGMA method and the relative contribution of the characters for genetic divergence. There was no genotype × cutting interval interaction and the genotypes presented a reduction on dry matter yield of roots, crown and aerial sections, number of stems and plant height when submitted to frequent cuttings. The most divergent genotypes were Marrocos and P9 (Md = 108.7) and the most similar ones were São Gabriel and P37 (Md = 7.8). The results suggest exclusion of the population P9 because of its weak performance and the utilization of the populations Corte and P37 as progenitors in the birdsfoot trefoil breeding program. Root dry matter accumulation and plant height were the characters that contributed most to genetic divergence and they can be used for selection works.

Acumulación de forraje de Lotus corniculatus L., en función a diferentes estrategias de cosecha

“…Las temperaturas favorables se presentaron en primavera (Figura 1), lo cual benefició el crecimiento y producción de la especie. Esto concuerda con lo reportado en cinco poblaciones de L. corniculatus, al utilizar un intervalo de pastoreo severo y uno intenso de 20 y 40 días, respectivamente (17) . Por lo tanto, los cambios estacionales en el rendimiento de una especie forrajera, pueden ser atribuidos a las condiciones ambientales presentes en cada estación del año (18) .…”

“…Estos resultados están relacionados con la edad de la pradera, ya que, en parcelas cosechadas en función del porcentaje de luz interceptada, la planta tuvo más días de rebrote con 70 días respecto al corte fijo con 33 días, promedio de ambos periodos (Figura 2). En el corte fijo, la edad de la planta fue menor, con cortes más frecuentes, reflejándose en un rendimiento de forraje menor (17) . Al respecto, se ha señalado que a una altura mayor corresponde un rendimiento mayor de forraje (15) y en el caso de Lotus corniculatus, el rendimiento y la altura, también se ha relacionado con los hábitos de crecimiento erectos y postrados (3) .…”

Objectives and approaches in the breeding of perennial legumes for use in temporary pasturelands

“…Furthermore, the legumes in the pasture are assigned the function to prolong the grazing season, to increase the yield and quality of grazing in the second half of summer and autumn. In this aspect, major breeding criteria prove to be productivity in secondary growth and rate of regrowth -in birdsfoot trefoil (Blumenthal and McGraw, 1999;Radović et al, 2008;Scheffer-Basso et al, 2011) and sainfoin (Martiniello, 2005), drought tolerance -in white clover (Caradus et al, 1995) and sainfoin (Demdoum et al, 2010), late beginning of fall dormancy and aftergrass character in combination with winter survival -in red clover and lucerne (Bouton, 2012).…”

Yield and Botanical Composition of Bird's-Foot-Trefoil Cultivars in Two-Component Mixture With Kenthucky Bluegrass

“…The overall sustainability and durability of cultivars is a function of the interaction between environmental conditions and their use. The genotypic results of this interaction are the cultural eco-types (7) suitable for joint cultivation in a specific region, using a specific agronomic practice (8,9). They are of significant in the consolidation of gene plasm with hay-mowing tolerance, stamping during grazing, high yield and forage quality (10).…”