Available resistance in alfalfa (Medicago sativa L.) cultivars is currently inadequate to control the alfalfa weevil, Hypera postica (Gyllenha), or potato Ieafhopper, ErnpoascaJabae (Harris), the two most injurious arthropod pests of alfalfa in North America. Resistance to both insects has been documented in other Medicago species having erect, glandular hairs. These hairs have been transferred to alfalfa. A field trial in 1985 was to determine the effects of erect, glandular hairs and their exudates on forage quality of several perennial Medicagos. Glandular and eglandular plant populations were selected from each of the diploids, M. prostrata Jacq. and M. glandulosa David., and tetraploids, M. glutinosa Bieb., M. sativa (MS4n) x M. glutinosa (KS160) and MS4n x M. prostrata (KS159). Eglandular M, sativa cv. Riley and diploid M. sativa ssp. caerulea (Less ex Ledeb.) Schmal. were included as controls. In vitro dry matter disappearance and CP concentration were determined for four harvests in 1985 and one in 1986. Leaves were separated from stems to obtain leaf percentage for three harvests in 1985 and one in 1986. The presence of erect, glandular hairs on the wild Medicago species or hybrids did not significantly affect dry matter disappearance, CP, or leaf percentage. Glandular- haired entries were similar in forage quality to alfalfa. Data from this study indicate that plant breeders may utilize erect, glandular hairs to improve pest resistance in alfalfa without affecting forage dry matter disappearance, CP, or leaf percentage.
- Medicago sp.,
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