Narrative
Medicago sativa
LUCERNE, ALFALFA
'Rapide'
Application No: 1997/294 Accepted: 12 Nov 1997.
Applicant: Seedco Australia Co-operative Limited, Hilton, SA.
Characteristics (Table 33, Figure 44) Plant: perennial, habit narrow, upright, height medium, very winter active (dormancy rating 10). Stem: green, anthocyanin absent, internodes medium, pubescent to sparsely pubescent. Leaf: trifoliate, central leaflet on pronounced pedicel, leaflet oblong-cuneate, sometimes denticulate at summit, moderately glabrous lower surface, sparsely glabrous upper. Inflorescence: oblong raceme to 30mm in length of 10 to 30 florets. Flower: blue to (mostly) purple, pea type, standard approximately 3mm in length. Seed: typically 4 to 8 borne in coiled pod of 3-5 coils to 5mm length, bright yellow to khaki, 4 to 500/gm.
Origin and Breeding Recurrent Phenotypic Selection: 'Rapide' is a 139 plant synthetic variety derived from recurrent phenotypic selection for resistance to spotted alfalfa aphid. The 139 selections derived from two very non-dormant breeding lines which were selected for persistence, rate of regrowth and resistance to silverleaf whitefly. One of the breeder's lines was developed from the cultivar 'Hassawi', while the other (designated WL 86-292) had parentage that traces to Pioneer 5929 and WL 605. Selection criteria: very high winter activity, increased seed yield. Propagation: by seed. Breeder: staff of SeedCo, Hilton, SA.
Choice of Comparators 'CUF 101' and 'Hassawi' were chosen for the comparative trial, as 'CUF 101' is a benchmark cultivar for highly winter active types such as 'Rapide', and 'Hassawi' is the major parent used to develop 'Rapide'. The other parent, WL 86-292 is a breeding line that is quite different to 'Rapide'. In particular, it is not as winter act ive. The other highly winter active (dormancy rating 9) lucerne cultivars of common knowledge, such as 'Pioneer L 90', 'Sceptre', 'Sequel', Sequel HR', 'WL 612', 'Siriver' were all considered as comparators, but all have significantly different pest and di sease resistance profiles, and were therefore excluded from the trial.
Comparative Trial Comparators: 'CUF 101', 'Hassawi'. Location: Currency Creek 75km SSE of Adelaide, between Aug 1999 and Mar 2000. Conditions: trial conducted in the field. The soil was a moderately fertile, free draining sandy loam of approximately pH 6. The trial was irrigated as required throughout the testing period. No chemical or fertiliser treatments were used and plots were hand weeded as required. Trial design: a randomised complete block with 4 replicates. Plants were seeded and raised in Jiffy 7 pellets in a shadehouse, and then transplanted into the field at approximately 5 weeks of age in Sep 1999. Each replicate was comprised of 20 plants in 4 rows, with 20 cm between plants and 50 cm between rows. Measurements: from all plants, or from whole rows as indicated.
Prior Applications and Sales Nil.
Description: Andrew W.H. Lake, Pristine Forage Technologies, Daw Park, SA.
Table 33 Medicago varieties
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'Rapide' 'Alpha Express' *'CUF 101' *'Hassawi'
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AVERAGE DAYS TO FIRST 25% PLANTS FLOWERING - from harvest on 2/1/00
mean 15.95b 16.15b 16.55b 12.95a
std deviation 0.46 0.39 0.78 0.50
(LSD at P0.01=0.94)
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NUMBER OF PLANTS/REP FLOWERING 16 DAYS AFTER CUTTING - from harvest on 2/1/00
mean 9.73b 7.23a 6.73a 11.48b
std deviation 0.63 1.57 1.74 0.77
(LSD at P0.01=2.23)
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NUMBER OF PLANTS/REP WITH MEDIUM OR STRONG STEM PUBESCENCE
(- data quoted is log transformed; ln (x +1))
mean 2.10c 0.58a 1.31b 2.36c
std deviation 0.179 0.524 0.142 0.193
(LSD at P0.01=0.607)
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PRESENCE OF PLANTS WITH STRONG STEM PUBESCENCE
present absent very rare present
(indicative %) (~10%) (<1%) (~1%) (~15%)
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