Defoliation frequency effects on winter forage production and nutritive value of different entries of Agropyron cristatum (L.) Gaertn

Abstract

The objective of this study was to evaluate the effect of different defoliation frequencies on winter forage production and nutritive value of improved population of Agropyron cristatum (L.) Gaertn. Four entries, a) base population, b) selected plants from mass honeycomb selection (MHS), c) selected plants from pedigree honeycomb selection (PHS) and d) selected plants from pedigree honeycomb selection using the combined criterion CC = x 2 (1 -CV) / CV [PHS (CC)] were tested under four defoliation frequencies: 1) frequent, 2) moderate, 3) infrequent and 4) control. Dry matter production under moderate defoliation treatment was 9% and 107% respectively higher than frequent and infrequent the first harvest year, while the second harvest year the corresponding percentages were 26% and 44%. The selected populations of A. cristatum consistently exceeded in herbage production the base population under all defoliation treatments during winter. Among the selected entries, [PHS (CC)] had consistently higher DM production compared to MHS and PHS for the two experimental years. The CP content was significantly higher, while NDF, ADF and ADL contents were lower in the increased defoliation frequency compared to the control in both harvest years. There were no significant differences of the nutritive value among the entries (P > 0.05). Generally, herbage production of the moderate defoliation frequency was more stable through the years with relatively high nutritive value.Additional key words: cool-season grasses, cutting frequencies, forage quality, sward management. ResumenEfectos de la frecuencia de defoliación en la producción y el valor nutritivo de forraje de invierno de diferentes entradas de Agropyron cristatum (L.) Gaertn El objetivo de este estudio fue evaluar el efecto de diferentes frecuencias de defoliación sobre la producción y el valor nutritivo de poblaciones mejoradas de Agropyron cristatum (L.) Gaertn. Se examinaron cuatro entradas: a) población base y plantas seleccionadas mediante b) selección masal en diseño «panal de abejas» (MHS), c) selección pedigree en diseño «panal de abejas» (PHS) y d) selección pedigree en diseño «panal de abejas» usando el criterio combinado CC = x 2 (1 -CV) / CV [PHS (CC)] bajo cuatro frecuencias de defoliación: 1) frecuente, 2) moderada, 3) infrecuente y 4) control. La producción de materia seca (MS) en el tratamiento de defoliación moderada fue un 9% y un 107% respectivamente más alta que en frecuente e infrecuente durante el primer año de recolección, mientras que durante el segundo año, los porcentajes correspondientes fueron 26% y 44%. Las poblaciones seleccionadas de A. cristatum sistemáticamente excedieron la producción de hierba de la población base en todos los tratamientos de defoliación durante el invierno. Entre las entradas seleccionadas, [PHS (CC)] presentó sistemáticamente una mayor producción de MS comparada con MHS y PHS en los dos años experimentales. El contenido de PB fue significativamente más alto, mientras que los de FND, FAD y LAD fueron más bajos...

Yield, Quality, and Other Characteristics of Selected Lines of Crested Wheatgrass

“…Similarly, Jefferson and Coulman (2008) and Rahmani et al (2009) reported that genotypes of crested wheatgrass showed significant differences in DMY. Moreover, significant differences were observed in DMY among 30 clonal lines of crested wheatgrass by Asay and Johnson (1997) and among four entries of crested wheatgrass by Abraham et al (2010). Conversely, Ciftci (2006) found that DMYs of crested wheatgrass per clone among 30 different clones presented no significant differences.…”

“…There were no significant differences in terms of CPC among the selected crested wheatgrass lines in this study. Also, Ciftci (2006) found no differences in CPC for 30 clones of crested wheatgrass, nor did Abraham et al (2010) for four entries. On the other hand, Ray et al (1996) determined that there was variation in CPC among 30 families of crested wheatgrass.…”

“…Crested wheatgrass is self‐incompatible and shows great variability in morphological characteristics (Mellish and Coulman, 2002; Ciftci, 2006; Jensen et al, 2009), dry matter yield (DMY) (Jefferson and Coulman, 2008; Rahmani et al, 2009; Abraham et al, 2010), seed yield (SY) (Serin et al, 2003; Rahmani et al, 2009), and quality characteristics (Mayland and Asay, 1989; Vogel et al, 1989).…”

Grazing as a Management Tool in Mediterranean Pastures: A Meta-Analysis Based on A Literature Review

“…The halting of the encroachment of grasslands by those plants is a key management problem in the Eastern Mediterranean grasslands [52]. Interventions such as fire and grazing have been recorded as insufficient or having little effectiveness at halting encroachment [53], even though a wildfire can have an effect on the cover, at least for a short period of time [54]. Finally, for four studies there was no comparison of the results between the application and lack of application of grazing after other structural interventions [55][56][57][58].…”

Effects of mowing regimes on forage yield and crude protein of Leymus chinensis (Trin.) Tzvel in Songnen grassland

“…mowing management. Regarding impact of mowing frequency on DM yield, Agropyron cristatum (L.) Gaertn had 49% and 78% more DM yield when mowed three or five times yearly, respectively, compared to mowing once yearly (Abraham et al, 2010). In contrast, mowing once yearly provided the highest annual DM yield of Leymus chinensis (Trin.)…”