Evaluating Temperate Species in the Subtropics. 3. Irrigated Lucerne

Tropical Grasslands (2010) Volume 44, 1-23 1

Evaluating temperate species in the subtropics. 3. Irrigated lucerne

K.F. LOWE1, T.M. BOWDLER1, N.D. CASEY1 in individual experiments was larger (1.1–5.7 t/ and P.M. PEPPER2 ha), taking into account the range from dormant 1Queensland Primary Industries and to highly active material. Fisheries, Mutdapilly Research Station, Peak Disease played a significant role in defining Crossing, Queensland, Australia production levels until the drought years of 2Queensland Primary Industries and 2001–2006, when the effects of colletotrichum Fisheries, Animal Research Institute, crown rot (CCR), phytophthora root rot (PRR) Brisbane, Queensland, Australia and the leaf disease complex of Stemphylium vesicarum and Leptosphaerulina trifolii were reduced. Trifecta was consistently in the group Abstract of cultivars showing most resistance to these diseases, while Hunter River showed equal or better Performance of lucerne cultivars and breeding resistance to colletotrichum crown rot and the lines, when grown under irrigation in the Queens- leaf disease complex. land subtropics in individual experiments and On average, only 12 – 20% of the original pop- when averaged over the 25 years from 1981 to ulations survived until the end of the third year, 2006, is presented. In the overall analyses, only with Hallmark, Trifecta and Sequel consistently cultivars which were entered in at least 2 exper- the most persistent cultivars. There was a wide iments were included. Entries were evaluated range in persistence between experiments (gen- in small plot cutting experiments over 3-year eral mean of 29% in 1984 compared with 5% in periods. Seasonal, annual and total dry matter 1995), with environmental conditions appearing yields were recorded, along with field disease to play as important a role as disease resistance. assessments and persistence. The best performing cultivars under sub- Highest seasonal, annual and total (60–64 t/ tropical conditions were winter-active (7 and 8) ha) yields were produced by highly winter-active or highly winter-active (9 and 9+) ones, that had cultivars (activity levels 8 and 9) with little dif- either been specifically bred for the region or ferences between Sequel, Sequel HR, Hallmark, undergone screening for disease resistance, par- Sceptre, Aquarius and Pioneer L90, although ticularly for CCR and PRR, which are recog- yields of a number of Queensland-bred cultivars nised as a problem in the region. Cultivars with with lower activity levels (<8) were not signifi- lower winter activity levels were generally lower- cantly lower. Individual experiments were more yielding, even though in some instances they discriminating, with the Queensland-bred culti- showed good persistence. vars Sequel and Trifecta producing the highest (P<0.05) or equal to the highest yields in 8 of 10 and 9 of 14 experiments in which they were Introduction included, respectively. Other high-yielding cultivars included Aquarius, Aurora, Genesis, Hall- Lucerne (Medicago sativa) remains one of the mark, Pioneer L55, Sceptre and UQL-1. Average most important forages for the Australian grazing winter yields ranged from 1.7 t/ha for Hunter industries. Over 200 000 ha are gown annually in River to 3.2 t/ha for Hallmark, while the range Australia to provide hay for the dairy, beef and horse racing industries (Irwin et al. 2001), with Correspondence: Kevin F. Lowe, Queensland Primary around 1.1 Mt of hay produced (Peace 2007). Industries and Fisheries, Mutdapilly Research Station, MS 825, Peak Crossing, Qld 4306, Australia. In 1997 in eastern Australia, aphids devastated E-mail: [email protected] lucerne stands, which were based on the single 2 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper cultivar, Hunter River. Cultivars imported from Treatments and design USA to fill the gap displayed a wide range in performance under irrigated (Lowe et al. 1985; Experiments were conducted when sufficient new 1987a) and raingrown conditions (Lloyd et al. cultivars or breeders’ lines were available. All were laid out as randomised blocks with 3 or 4 1985). While insect resistance was important, replicates. The number of treatments per experi- resistance to local diseases was equally critical ment varied from 4 to 35, with the lower treatment (Irwin 1977), particularly in the subtropical areas numbers associated with 4 replicates. Treatments of Australia. Breeding programs were begun in included elite breeders’ lines of lucerne, selected Australia to develop cultivars with better adap- by public and commercial plant breeders from tation to the region (Irwin et al. 2001). Most of their programs, together with newly released these early Australian-bred lines were based on and standard (benchmark) commercial cultivars. CUF 101 to provide aphid resistance (Lowe et Experiments also contained cultivars and experi- al. 1987a; Irwin et al. 2001) and the most winter- mental lines from USA. Generally, the standards included Hunter River, Trifecta or Sequel, but active (activity levels 8 and 9) cultivars have other standards were included when requested by proved the highest-yielding types in the sub- seed companies. tropical environment under both irrigated and raingrown conditions (Irwin et al. 2001). The advantage gained from better persistence from Techniques less dormant cultivars in cooler environments (Humphries et al. 2008) does not appear to hold In July or August, seed was sown at 15 kg/ha by hand into weed-free seedbeds, which were then in the subtropics, where a range of acute dis- rolled and irrigated. Plot size was 5 m x 2 m. eases actively reduce plant populations (Lowe et Experimental seed was hand-scarified but it was al. 1985; Lloyd et al. 1985; D.L. Lloyd, personal assumed that mechanical harvesting provided communication). sufficient scarification for commercially- pro This paper, the third in the series to eval- duced seed. uate temperate species in the Queensland subtropics, reports the performance, under irrigation, For the first 4 weeks, 12.5 mm of irriga- of the cultivars produced by the Australian tion was applied weekly but subsequently plots received 50 mm every 2 weeks using a fixed, lucerne breeding industry since 1977, along with solid-set layout with overhead sprinklers to imported cultivars from USA. Total and sea- ensure DM yields were not limited by soil mois- sonal yield, persistence and disease resistance of ture stress. Irrigation schedules were maintained around 220 breeders’ lines and released cultivars unless more than 25 mm of rainfall was received are reported for the period 1981–2006. in the week prior to application. Superphosphate, to provide 18 kg/ha P and 22 kg/ha sulphur (S), was applied during the second and third spring Materials and methods periods to satisfy a known sulphur deficiency at the sites. Swards were sprayed when necessary Site (usually once or twice a year) with Fluazifop-p at a rate of 2 L/ha to control the invasion of grasses. Seventeen field evaluations were conducted at Harvesting of each experiment commenced Gatton Research Station (27o 34’ S, 152o 20’ E; around 10 weeks after sowing. Regrowth was elevation 95 m) in south-east Queensland from assessed over a 3-year period every 4 weeks except in winter, when the interval was extended 1981 to 2006. The soils are deep, alluvial black to 6 weeks. DM yield was measured by cut- clays (black earth, Stace et al. 1972; Ug 5.15 ting, to 5 cm above ground level from the cen- and 5.16, Northcote 1971) with pH of 7.8–8.3 tral section of each plot, a quadrat of 2.25 (before (H2O) and containing 128–134 mg/kg P (Colwell 1997) or 5.85 (1997–2006) m2 using a recipro- extraction), 0.87–1.0 mmole/100 g potassium (K) cating mower. When weeds were present, the and 67–70% clay. botanical composition of the harvested herbage Evaluating irrigated lucerne in the subtropics 3 was determined by sorting a sub-sample into and annual rainfalls in the second period (1994– legume and weed components. Samples were 2006) were below average, subsequently referred dried in a forced-draught oven at 80oC for 24 h. to as the ‘dry’ period. Maximum temperatures in The remaining pasture residues on each plot were the ‘normal’ period were around the long-term removed using a forage harvester. average and autumn and winter minimum tem- Seasonal yields were calculated by summing peratures were above average. Maximum and individual yields from the samplings that fell minimum temperatures for all seasons in the dry within the following periods: Autumn – 1 March period were similar to the long-term average. to 31 May, Winter – 1 June to 31 August, Spring Relative humidity and radiation differences – 1 September to 30 November and Summer – between the 2 periods were small. Minimum rel- 1 December to 28/29 February. A sampling was ative humidity showed greater variation between deemed to fall into a season if more than half the seasons than the maximum. growth period occurred in that season. Rainfall was very low in 1993 (345 mm), Incidences of the diseases phytophthora root 1994 (486 mm), 2000 (459 mm) and 2002 (387 rot (PRR) (Phytophthora medicaginis), anthra- mm), as was relative humidity in summer. On the cnose (Colletotrichum trifolii) and the leaf spot other hand, rainfall exceeded 1000 mm in 4 of complex (Stemphylium vesicarium and Lept- the 13 years (1981–1993) but only once between osphaerulina trifolii) were scored visually using 1994 and 2006 (1037 mm, 1996). Summer tem- a scale of 0-5, described in Anon. (2007) but peratures were well above average in 1984–1986 with modifications described by Gramshaw et al. (32.3ºC), 1990 (32.0ºC), 1997 (32.6ºC), 2001 (1985) and Lowe et al. (1987a; 1987b). Anthra- (32.8ºC) and 2003 (32.4ºC), peaking in 2005 cnose was scored on lesions evident on stems. (33.3ºC). Winters were coldest in 1982 (5.1ºC), Colletotrichum crown rot (CCR), which invades 1994 (5.1ºC), 2000 (5.8ºC) and 2002 (5.8ºC), and the crown (Irwin 1974), was not assessed in were mild in 1983 (8.1ºC), 1988 (8.4ºC), 1993 these experiments. All assessments were carried (8.4ºC), 1998 (9.0ºC) and 1999 (8.0ºC). out only when epiphytotics occurred. No disease assessments were conducted between 2001 and 2006 because symptoms of disease were min- Statistical analyses imal, owing to prevailing dry conditions. Counts were recorded in a 2 m x 0.25 m per- Data for DM yields, persistence and disease manent quadrat, positioned approximately in the effects were subjected to analysis of variance centre of each plot, 6 weeks after sowing and using the statistical package ‘GenStat’ (Payne again in May and October of each year. Plant sur- et al. 2007). Weighted, modified joint regres- vival at each count was assessed as a percentage sion analyses (Digby 1979) were undertaken of the initial population. Persistence was defined on 3-year total yields, yield in Year 1, seasonal as the number of plants remaining at the end of yields, % of yield in winter, % of yield in Year the experiment, expressed as a percentage of the 3, final persistence and disease scores. The tech- initial density. nique has been described in Lowe et al. (2007); however, in this instance, ‘environment’ was defined as different 3-year periods. Results for Climate any cultivar or breeders’ line, which appeared in only one environment, were not used in the Seasonal and total rainfall and seasonal maximum analysis. For some cultivars/breeders’ lines, the and minimum temperatures, relative humidity iterative process did not converge and it was nec- and radiation received for years 1984–2005 have essary to drop those which appeared only a few previously been published in Lowe et al. (2007; times to attain convergence. The sensitivities of 2008). Seasonal rainfall and temperatures varied each cultivar to environmental effects are plotted considerably between years, with winter temper- against the final estimates of the cultivar means. atures the most variable. Over the first 13-year Cultivars with a large mean (or a small mean period (1981–1993), autumn and total rainfalls in the case of disease scores) and a sensitivity were well above the long-term average, subse- of around 1.0 should indicate a reliable cultivar quently referred to as the ‘normal’ period (Table under variable conditions, as proposed by Finlay 1). On the other hand, autumn, winter, summer and Wilkinson (1963). Cultivars with a high sen- 4 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper

Table 1. Seasonal and total rainfall averages (mm), seasonal average maximum and minimum temperatures (ºC) and relative humidity (%) and seasonal daily radiation received (MJ/m2) at Gatton Research Station from 1981 to 2006. Long-term average is over 66 years for temperature and 98 years for rainfall. Averages for relative humidity and radiation are not available.

Mean 1981–1993 (+ s.e.) Mean 1994–2006 (+ s.e.) Long-term average

Rainfall Autumn 236+39 138+33 178 Winter 117+22 64+9 111 Spring 171+17 179+21 176 Summer 292+33 274+26 313 Annual1 826+63 662+52 778 Maximum temperature Autumn 26.5+0.3 27.0+0.2 26.9 Winter 21.0+0.7 21.7+0.6 21.2 Spring 27.6+0.3 28.1+0.3 28.0 Summer 31.2+0.3 31.4+0.3 31.2 Minimum temperature Autumn 14.5+0.3 14.0+0.2 13.8 Winter 7.1+0.3 6.9+0.3 6.6 Spring 12.6+0.2 13.1+0.2 12.7 Summer 18.9+0.2 19.0+0.2 18.8 Maximum relative humidity Autumn 97.1+0.3 96.8+0.3 - Winter 96.0+0.3 96.5+0.5 - Spring 93.4+0.4 94.0+0.7 - Summer 95.1+0.6 94.2+0.7 Minimum relative humidity Autumn 52.4+1.4 48.9+0.7 - Winter 46.1+0.9 45.0+1.1 - Spring 41.9+0.9 42.5+1.2 - Summer 48.7+0.7 48.1+0.7 Radiation Autumn 16.2+0.3 16.9+0.1 - Winter 14.3+0.2 14.4+0.2 - Spring 22.0+0.3 22.0+0.3 - Summer 22.8+0.2 23.0+0.1

1 Annual rainfall - based on a calendar year. sitivity have below average stability and are spe- Results cifically adapted to favourable environments, while those with sensitivities below 1.0 are spe- Total yields cifically adapted to unfavourable environments (Finlay and Wilkinson 1963). Overall performance. The performance of the To assess the potential for reducing the assess- top-yielding cultivars was not significantly dif- ment period for lucerne in this environment, ferent, averaged over the 25 years of experi- simple and multiple correlations were calculated. The data for these analyses were split into mentation (Figure 1). As a result of the differing 2 periods, 1981–1996 and 1997–2003 as the number of times cultivars were included in exper- ’normal’ and ‘dry’ periods, respectively. For the iments (resulting in large standard errors for culti- period 1981–1996, field disease rankings were vars with few occurrences), the analysis failed to also included as explanatory variables. distinguish between Hallmark (average 64.0 t/ha) Evaluating irrigated lucerne in the subtropics 5

Figure 1. The relationship between cultivar adaptation (regression coefficient = sensitivity) and cultivar mean total DM yield over 3-year evaluation periods for cultivars (+) and experimental lines (*) of lucerne. A new experiment was sown annually for 25 years over the period 1981–2005 at Gatton in south-east Queensland, although the 2006 experiment was not included in this data as it had not been completed at the time. Cultivars with the same superscript are not significantly different at P=0.05. and Aurora (59.7 t/ha) or Maxidor II (56.4 t/ha). other cultivar (P<0.05). Trifecta was the top- Hunter River yielded significantly less than all yielding cultivar or was not significantly different other cultivars except L34HQ, WL 516, Sirosal from the top-yielding cultivar in 9 of 14 experi- and DK 187. Cultivars such as Sequel, UQL-1, ments. The best experimental line produced the Sceptre and Trifecta are likely to perform well highest yield (P<0.05) or was not significantly under most environmental conditions (i.e., they different from the highest-yielding entry in 12 produced good yields with a sensitivity around 1). On the other hand, Eureka, Sequel HR and experiments. Other top-performing cultivars were Hallmark should perform best in more favour- Aquarius (1995 and 1997), Aurora (1996, 1999 able environments, while Aurora, Granada and and 2003), Genesis (1989 and 2003), Hallmark Venus are likely to perform relatively better than (1995, 1997, 2003 and 2005), Sceptre (1986, other cultivars under unfavourable conditions. A 1989 and 2000) and UQL-1 (1997, 1998 and number of experimental lines performed as well 2000). Cultivars, which reached the top-yielding as the top cultivars. group on one occasion, included CUF 101, Gra- Individual experiment performance. Sequel pro- nada, Pioneer 5929, Pioneer L52, Pioneer L55, duced the highest cultivar yield (P<0.05) or was not significantly different from the highest cul- Pioneer L69, Pioneer L90, Queensland 11, Rippa, tivar yield in 8 of the 10 experiments in which it SARDI 5, Sequel HR and WL 516. Hunter River was included (Table 2). In one of the other exper- produced the lowest yields in all but 2 of the 8 iments (1982), Sequel outyielded all except one experiments in which it was included. 6 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper 59.9 65.7 2005 58.8 58.1 59.5 59.8 58.8 2003 55.8 59.8 2001 51.0 50.6 50.1 43.5 43.6 50.7 46.8 2000 48.1 51.9 1999 40.0 52.2 1998 50.9 50.7 51.6 41.6 1997 67.7 70.5 1996 5 54.2 53.4 56.5 42.2 1995 DM yields (t/ha) 4 53.2 42.7 50.3 52.5 1995 64.0 65.4 60.6 46.5 63.5 1993 58.9 66.7 56.9 1989 76.7 81.7 59.9 1986 63.0 64.6 52.2 62.5 54.2 1984 3 61.7 52.4 35.1 56.1 53.9 58.3 55.5 32.5 56.8 57.7 1982 3 48.6 52.4 48.3 52.4 48.0 45.8 48.9 56.4 49.8 33.8 53.3 49.6 53.8 53.3 52.6 44.8 39.4 45.9 48.7 1981 2 6 9 3 5 4 5 5 8 9 8 6 9 4 6 9 8 6 9 9 6 6 7 9 8 9 9 5 6 9 8 9 9 9 6 4 5 8 9+ Activity level 1 Country of origin NSW NSW USA USA USA USA USA USA USA USA SAust NSW SAust NSW USA Qld USA USA Aust SAust USA USA USA USA USA NSW USA USA USA USA USA USA USA USA USA USA USA USA Total DM Total yields of lucerne cultivars over 3-year periods from sowings made annually from 1981 to 2005. Best and worst experimental lines provide the range of performance of breeding Cultivar Aquarius Aurora Baron Cimarron Condura 73 CUF 101 Diamond DK 167 DK 185 DK 187 Eureka Falkiner Generation Genesis Granada Hallmark Haymaker Haymaker II Hunter River Hunterfield Matador Maxidor I Maxidor II Megluce I Megluce II Nova Pioneer 532 Pioneer 555 Pioneer 577 Pioneer 581 Pioneer 5929 Pioneer L34HQ Pioneer L52 Pioneer 54Q53 Pioneer L55 Pioneer L56 Pioneer L69 Pioneer L90 Table 2. Table lines and differ from year to year. Evaluating irrigated lucerne in the subtropics 7 1.7 64.3 58.0 64.2 61.4 62.1 56.3 62.5 47.7 60.5 2005 2.1 57.0 52.6 58.2 56.5 57.6 55.3 57.3 2003 3.5 62.1 55.6 65.0 56.4 58.7 2001 2.2 53.4 54.1 54.1 51.9 53.5 55.3 51.8 50.9 2000 2.4 49.3 50.2 52.6 42.3 49.3 1999 5.0 56.2 58.4 56.2 40.4 51.1 1998 3.6 51.6 51.9 53.0 47.3 54.9 43.4 50.5 1997 ns 70.7 69.9 72.2 70.4 70.3 1996 5 3.6 53.3 57.2 52.7 55.3 56.3 51.5 53.6 1995 DM yields (t/ha) - - 4 2.9 49.7 1995 4.7 59.3 65.0 66.5 68.5 59.5 72.8 58.6 63.2 1993 4.2 51.3 63.5 61.4 42.6 63.5 66.5 53.4 60.4 1989 4.8 84.1 86.7 74.8 84.8 72.1 81.5 75.0 75.2 85.1 73.8 79.0 1986 3.4 67.3 73.0 72.0 69.1 60.2 64.3 1984 3 2.9 64.7 49.6 68.1 59.6 48.1 54.3 1982 3 6.4 42.3 46.2 50.5 47.5 45.9 60.9 38.2 45.2 42.9 46.9 35.8 34.8 47.6 1981 2008). 2 7 9 9 7 5 7 9 9 6 9 9 9 5 6 7 7 9 7 4 5 6 3 5 6 8 9 3 10 9+ et al. Activity level (1987a). 1 et al. Country of origin Qld USA USA USA SAust SAust SAust SAust Qld Qld SAust ACT ACT ACT ACT SAust USA Qld USA Qld USA NSW SAust USA USA USA USA USA USA 6 Different experiments conducted in the same year. Cultivar Quadrella Queensland 11 Rippa Sapphire SARDI 5 SARDI 7 SARDI 10 Sceptre Sequel Sequel HR Sheffield Siriver Siro Peruvian Sirosal Siro Tasman Springfield Stargrazer Trifecta UC Cibola UQL-1 Validor Venus Wakefield WL 320 WL 515 WL 516 WL 525HQ WL 605 WL Southern Special Best exp. exp. Worst General mean LSD (P=0.05) USA – USA United States America, of NSW – New SAust South – Wales, Aust Australia, South – Qld natural – Australia. ACT Australian selection, Queensland, – Capital Territory, Based Anon. on (2007) where 1 = completely winter-dormant and 9 = highly winter-active. Note: New material from Arabia Saudi now suggests that there is a further category – 10, which is more Data reproduced from Lowe Best experimental line. 1 2 active than the original 9 category (Irwin 3 4, 5 6 8 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper

First-year yields was most evident after 1995 (Table 3). Sequel was equal to the top-yielding entry in all but 2 Overall performance. Sequel HR was the of the experiments in which it was included. Tri- highest-yielding cultivar in the first year (23.3 fecta was the top-yielding or equal top-yielding t/ha) in absolute terms but it was not different cultivar from 1981 to 1997 (except for the 1993, (P>0.05) from 15 other winter-active or highly 1995 and 1996 experiments) but after 1998 it was winter-active cultivars (Figure 2). Pioneer 581 never in the top-yielding group. Other cultivars to yielded significantly less than Sequel HR,- Pio fall into the top-yielding group included Sceptre neer L69, Hallmark, Sequel, UQL-1, Sceptre, (1986, 1989 and 1995), Sequel HR (1993, 1995 SARDI 10 and Trifecta. Hunter River yielded and 2000), UQL-1 (1997 and 1998), Hallmark less (P<0.05) than all except Cimarron, Pioneer (1995, 1997 and 2005), Genesis (1989 and 1997) L34HQ, Pioneer L52, SARDI 7 and WL 516. and Aquarius (1995 and 1997), while Baron, CUF Sequel HR, Pioneer L69 and Pioneer L90 were 101, Granada, Generation, Maxidor II, Pioneer superior under favourable conditions and SARDI L69, Queensland 11 and WL 516 were equiva- 10, Maxidor II and Granada were superior under lent to the best entry on one occasion. Many of less favourable conditions. A number of experi- these high-performing entries were equal to the mental lines performed as well as the best culti- second highest-yielding entry on further occa- vars in the first year. sions. Hunter River produced low yields in every Individual experiment performance. In contrast experiment, always being lower than the general to the 3-year totals, the best experimental line experimental mean. was usually the top-yielding (P<0.05) or equal The best entries yielded 17–29 t/ha DM, top-yielding entry in the first year; this trend depending on the seasonal conditions experi-

Figure 2. The relationship between cultivar adaptation (regression coefficient = sensitivity) and mean first-year DM yield for cultivars (+) and experimental lines (*) of lucerne. The 2006 experiment was included in this analysis. Cultivars with the same superscript are not significantly different at P=0.05. Evaluating irrigated lucerne in the subtropics 9 enced. Most were highly winter-active and were foregoing groups but were not different (P>0.05) bred in Queensland or, if bred elsewhere, have from the highly active lines. had strong selection pressure for CCR and PRR.

Disease Seasonal yields Overall performance. Disease played a signifi- Overall performance. Winter production of semi- cant role in the performance of cultivars before dormant and dormant cultivars (activity levels very dry conditions commenced in 2001. Sub- below 7) such as Pioneer L34HQ, Cimarron, sequent to this, little disease was evident and no Pioneer 581 and Hunter River was significantly assessments were conducted (Table 5). There- (P<0.05) lower than that of winter-active and fore, the overall analyses have been conducted highly winter-active cultivars (except for the only for the period 1981–1998 for PRR and the poorly performing DK 187 and Sirosal). Within leaf disease complex and 1981–2000 for anthrac- the winter-active and highly winter-active culti- nose. Trifecta showed the best (P<0.05) or equal vars, there were no significant differences (Table best resistance to all 3 diseases among the cul- 4). Spring yields of the majority of cultivars tivars (Table 4). It was significantly better than were similar, although Hunter River, DK 187 and Pioneer 581, DK 187, WL 516, Sirosal and Hay- Sirosal produced less (P<0.05) than most other maker I for resistance to anthracnose. A ranking cultivars. of 2 or less indicated that these cultivars would Apart from significant differences between be expected to show symptoms no worse than Pioneer L55 and Hallmark and a group including small dark lesions on the stems and little damage SARDI 10, CUF 101, Quadrella, Aurora, Cima- in the plant crown under moderate disease attack. rron, Hunter River, DK 187 and Sirosal, there Trifecta was also more (P<0.05) resistant to PRR were no significant differences (P>0.05) in than Granada, Haymaker I, Hunter River, Quad- summer yield between the majority of the culti- rella and Sirosal. Under moderate PRR infec- vars. Hallmark yielded more (P<0.05) in autumn tion, most plants would show only small lesions than Aquarius, CUF 101, Sceptre, UQL-1, Pio- on the roots with this level of resistance. Damage neer L69, Pioneer L52, Pioneer L34HQ, Hunter was greater from the leaf disease complex, with River and DK 187. Again there was little dif- none of the cultivars showing ‘resistance’ and all ference between most of the remaining winter- cultivars recording levels of 3 or more. In 1989, active and highly winter-active cultivars. Quadrella, which had been selected from Trifecta for Stemphylium resistance, showed significantly more resistance (2.04) than Trifecta (2.64) (Table Percentage of yields produced in winter 5). Generally, Quadrella, Trifecta, Cimarron and Hunter River showed the least damage from the Overall performance. Despite some cultivars leaf spot complex among cultivars, although dif- being included in only a small number of years, ferences were generally not significant (P>0.05). the data in Figure 3 for percentage of total yield Individual experiment performance. Trifecta and produced in winter agreed well with the activity Hunter River were generally the most (P<0.05) levels presented in Table 2. Highly winter-active resistant cultivars to anthracnose infection (or cultivars such as Pioneer L90, Granada, Max- equal most resistant) (except in 2000) (Table 5). idor II, SARDI 10, CUF 101, Sequel and Sequel The best experimental line showed similar resist- HR were not significantly different. The anal- ance to the best cultivar in individual experi- ysis generally did not distinguish between these ments except in 2000. Other cultivars showing and winter-active lines such as Hallmark, Pio- good resistance were Pioneer 532, Pioneer 577 neer L69, UQL-1, Aurora, Aquarius, WL 516 and and Wakefield (1981), Sequel, Haymaker and Quadrella. However, the semi-dormant and dor- Hunterfield (1982), Sequel (1984), WL 320 mant cultivars such as Pioneer L34HQ, Cimarron (1986), Eureka and Sequel HR (1995) and Pio- and Pioneer 581 were distinguished as inferior neer L34HQ, Pioneer 54Q53 and UQL-1 (2000). (P<0.05). Venus, Pioneer L55 and Pioneer L52 In 2000 Trifecta showed as much damage as the were intermediate in performance between the worst affected cultivar, which may have been due 10 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper 2006 23.4 23.4 24.3 20.4 22.3 23.4 21.2 2005 25.6 25.9 2003 22.1 22.6 23.2 22.8 24.3 2001 22.4 22.2 2000 18.4 19.8 16.7 15.9 15.6 19.1 19.1 1999 18.4 18.6 1998 17.0 20.3 1997 17.1 17.4 17.5 13.6 1996 27.3 27.2 DM yields (t/ha) 2 1995 21.3 19.5 21.4 13.8 1 1995 17.1 14.6 15.7 16.5 1993 23.2 22.8 22.8 24.5 17.7 26.2 1989 15.8 19.7 16.4 1986 23.2 16.2 24.1 1984 23.6 25.1 17.3 20.6 22.2 1982 21.5 19.1 21.4 20.3 19.2 11.8 13.8 20.5 21.0 20.2 1981 11.0 10.8 16.2 10.7 11.6 10.6 16.4 13.3 4.9 14.3 14.1 16.3 15.0 14.9 11.2 8.9 10.5 10.5 12.8 First-year DM yields of lucerne cultivars from sowings made annually from 1981 to 2006. Best and worst experimental lines provide the range of performance of breeding lines and differ Cultivar Aquarius Aurora Baron Cimarron Condura 73 CUF 101 Diamond DK 167 DK 185 DK 187 Eureka Falkiner Generation Genesis Granada Hallmark Haymaker Haymaker II Hunter River Hunterfield Matador Maxidor I Maxidor II Megluce I Megluce II Nova Pioneer 532 Pioneer 555 Pioneer 577 Pioneer 581 Pioneer 5929 Pioneer L34HQ Pioneer L52 Pioneer 54Q53 Pioneer L55 Pioneer L56 Pioneer L69 Pioneer L90 Table 3. Table from year to year. Evaluating irrigated lucerne in the subtropics 11 2006 24.6 22.4 22.7 24.0 22.1 22.4 22.5 21.5 26.4 19.3 23.4 1.6 2005 24.4 24.6 26.0 24.2 25.1 23.0 26.1 23.4 25.0 1.0 2003 23.2 23.6 24.7 22.8 25.3 21.5 23.2 0.9 2001 25.6 20.5 26.6 22.1 23.4 1.7 2000 20.1 21.1 21.0 18.9 19.9 20.3 19.1 19.1 0.9 1999 17.6 17.8 20.5 16.3 18.3 1.4 1998 21.3 23.6 22.7 19.4 20.9 2.5 1997 16.7 17.1 16.8 18.5 18.4 14.4 17.0 1.8 1996 27.0 28.7 29.6 27.4 28.1 1.8 DM yields (t/ha) 2 1995 20.7 21.3 21.1 19.6 21.5 19.2 20.0 1.2 1 1995 - - 16.0 ns 1993 22.0 24.4 25.5 27.2 22.7 26.3 23.0 23.9 2.3 1989 15.3 19.4 18.4 15.0 19.1 20.1 15.3 17.8 1.8 1986 25.7 26.7 22.5 26.1 21.6 23.7 21.3 21.9 26.1 22.3 23.5 2.2 1984 25.9 27.4 29.0 26.7 22.9 24.7 1.5 1982 23.1 17.4 23.0 21.5 17.0 19.5 1.6 1981 8.0 10.9 13.3 13.4 11.5 17.2 10.5 12.1 9.0 13.1 12.7 10.7 12.1 2.1 3 Different experiments conducted in the same year. Cultivar Quadrella Queensland 11 Rippa Sapphire SARDI 5 SARDI 7 SARDI 10 Sceptre Sequel Sequel HR Sheffield Siriver Siro Peruvian Sirosal Siro Tasman Springfield Stargrazer Trifecta UC Cibola UQL-1 Validor Venus Wakefield WL 320 WL 515 WL 516 WL 525 WL 605 WL Southern Special Best exp. exp. Worst General mean LSD (P=0.05) Best experimental line. 1,2 3 12 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper Sens 3.06 1.03 0.38 0.9 2.87 0.38 3.12 0.52 1.12 7.61 1.43 1.02 0.65 0.51 1.10 2,3 Stemp. 3.34 3.28 2.91 3.44 3.79 2.92 3.44 3.13 3.55 4.6 3.55 3.03 3.36 2.86 3.72 Sens 0.43 0.37 0.53 1.21 2.03 1.46 -4.16 0.48 -2.87 0.99 4.75 0.56 0.8 3.04 1.17 0.84 2.42 1.81 1.04 0.91 1.06 hi h bcde cdefghi bcde bcdefg abc defghi ab a defghi abcdefghi eghi bc defghi ghi cdefgi bcd eghi fhi bcdef Disease ranking PRR 1.68 1.65 2.65 2.17 2.44 2.28 3.56 2.09 3.68 3.39 1.28 2.30 2.05 2.79 2.14 1.86 2.27 2.60 2.02 1.84 2.40 Sens 1.24 0.97 0.56 0.48 -0.85 5.96 1.14 1.29 0.15 0.89 0.85 0.83 0.73 2.02 0.86 2.83 0.66 1.59 bcdefgh fgh cdefgh b bcdefgh a gh abcdefgh bcdefgh cdefg defgh efgh gh bcde bcdef bcdef bc h CCR 2.61 2.21 2.35 3.14 1.68 5.00 2.14 2.74 2.22 2.41 2.29 2.29 1.93 2.60 2.11 2.52 2.54 2.75 Sens 1.09 0.58 2.4 0.81 1.73 1.4 0.82 0.97 1.26 0.63 1 0.84 -0.1 0.72 0.38 0.99 1.58 -1.51 1.18 0.83 1.39 0.69 0.45 1.5 1.29 2.09 Autumn efghi abcdegh abcdefghij fgi fik abcdegh abcde abcdefghij ac abcdefghij jkl abcdefghij abcdefghij cfghi jkl fhij efghij abcdefghij bdefgh abcd abcdegh abcdeh defghi abcdefghij ab abcdefghij Best experimental line. 4 Yield 3485 3787 3868 3462 2453 3784 3875 3856 4030 3284 2728 3542 3005 3465 2742 3253 3266 3139 3613 3863 3678 3754 3535 3286 4314 2474 Sens 1.11 0.75 -2.79 0.74 1.5 1.18 1.47 0.59 1.23 0.8 0.39 0.79 0.66 0.76 1.61 0.96 2.04 0.71 2.14 -0.14 1.53 1.06 1.12 1.03 1.63 1.13 1.12 -1.22 1.01 1.50 -5.67 de Summer abcde ce ghi fg ij abcdefg abcd abcdefg ad defghi hi defghi abcdefgh abcdefg abcdefghi abcdef ab abcdefghi abcde fghi ef abcde abcd abcdefgh j bce abcdef abcdef abcde abcdefghij 41abc Yield 7034 6786 5439 6206 4542 7090 7310 6712 7318 6185 5400 6139 6619 6857 7452 6750 8149 6342 7841 6039 6517 6807 7053 6956 3730 6866 69 7510 6928 7717 3175 No significant differences. 3 Sens 1.22 0.82 1.11 1.79 0.89 0.92 1.11 0.47 0.45 0.87 1.3 1.53 1.19 2 -0.27 0.74 0.89 1.08 0.8 1.2 0.99 1 0.76 0.85 0.93 0.71 Spring abcde abcd ce h abcdef abcd abcd fg bdef def abcde a abcd ab abcdefgh abcd abd abcdef abcd ab abcd abcdef abcde abcdef def eg leaf spot complex. Yield 6493 6456 6064 3681 6370 6551 6590 5401 6021 5994 6376 7002 6562 6969 5240 6011 6377 6565 6120 5311 6467 6705 6545 6313 6571 6261 1 Sens 1.03 0.72 0.26 0.84 1.07 1.41 0.91 1.2 0.56 0.44 1.6 3.58 0.47 1.3 0.64 1.1 1.27 1.13 1.13 1.57 1.05 0.97 1.02 1.05 0.66 1.29 1.43 Leptosphaerulina / Winter def efg j de abcdefghij bcdefg bcde bd ij h abcdefghij cefg abcdefg cefg fgh abcdefg bcd b bcde ghi ce bcdef bcdefgh abcdefgh a bcdefg j Yield 2805 2670 1052 2826 1989 2795 2856 3200 1654 2095 1165 2677 2647 3177 2714 2317 3052 3051 3167 3005 2138 2837 2841 2471 3059 3850 2776 Stemphylium

2 4 The relationship between cultivar adaptation (regression coefficient=sensitivity) and mean seasonal yield and disease ranking for lucerne cultivars at Gatton. Best and worst experimental r Sens –sensitivity. Sens –sensitivity. Cultiva Aquarius Aurora Cimarron CUF 101 DK 187 Eureka Genesis Granada Hallmark Haymaker I Hunter River Matador Maxidor II Pioneer 581 Pioneer L34HQ Pioneer L52 Pioneer L55 Pioneer L69 Pioneer L90 Quadrella SARDI 10 Sceptre Sequel Sequel HR Sirosal Trifecta UQL-1 Venus WL 516 Best exp. exp. Worst Table 4. Table lines provide the range of performance of breeding lines and differ from year to Cultivars year. with the same superscript are not significantly different at P=0.05. 1 Evaluating irrigated lucerne in the subtropics 13 Sens 3.06 1.03 0.38 0.9 2.87 0.38 3.12 0.52 1.12 7.61 1.43 1.02 0.65 0.51 1.10 2,3 Stemp. 3.34 3.28 2.91 3.44 3.79 2.92 3.44 3.13 3.55 4.6 3.55 3.03 3.36 2.86 3.72 Sens 0.43 0.37 0.53 1.21 2.03 1.46 -4.16 0.48 -2.87 0.99 4.75 0.56 0.8 3.04 1.17 0.84 2.42 1.81 1.04 0.91 1.06 hi h bcde cdefghi bcde bcdefg abc defghi ab a defghi abcdefghi eghi bc defghi ghi cdefgi bcd eghi fhi bcdef Disease ranking PRR 1.68 1.65 2.65 2.17 2.44 2.28 3.56 2.09 3.68 3.39 1.28 2.30 2.05 2.79 2.14 1.86 2.27 2.60 2.02 1.84 2.40 Sens 1.24 0.97 0.56 0.48 -0.85 5.96 1.14 1.29 0.15 0.89 0.85 0.83 0.73 2.02 0.86 2.83 0.66 1.59 bcdefgh fgh cdefgh b bcdefgh a gh abcdefgh bcdefgh cdefg defgh efgh gh bcde bcdef bcdef bc h

CCR 2.61 2.21 2.35 3.14 1.68 5.00 2.14 2.74 2.22 2.41 2.29 2.29 1.93 2.60 2.11 2.52 2.54 2.75 Cimarronhm Sens 1.09 0.58 2.4 0.81 1.73 1.4 0.82 0.97 1.26 0.63 1 0.84 -0.1 0.72 0.38 0.99 1.58 -1.51 1.18 0.83 1.39 0.69 0.45 1.5 1.29 2.09 Autumn efghi abcdegh abcdefghij fgi fik abcdegh abcde abcdefghij ac abcdefghij jkl abcdefghij abcdefghij cfghi jkl fhij efghij abcdefghij bdefgh abcd abcdegh abcdeh defghi abcdefghij ab abcdefghij Best experimental line. 4

Yield 3485 3787 3868 3462 2453 3784 3875 3856 4030 3284 2728 3542 3005 3465 2742 3253 3266 3139 3613 3863 3678 3754 3535 3286 4314 2474 Figure 3. The relationship between cultivar adaptation (regression coefficient = sensitivity) and the percentage of total yield produced in winter for cultivars (+) and experimental lines (*) of lucerne. Cultivars with the same superscript are not significantly different at P=0.05. Sens 1.11 0.75 -2.79 0.74 1.5 1.18 1.47 0.59 1.23 0.8 0.39 0.79 0.66 0.76 1.61 0.96 2.04 0.71 2.14 -0.14 1.53 1.06 1.12 1.03 1.63 1.13 1.12 -1.22 1.01 1.50 -5.67

to the presence of Race 4 of C. trifolii (Mackie Persistence de Summer abcde ce ghi fg ij abcdefg abcd abcdefg ad defghi hi defghi abcdefgh abcdefg abcdefghi abcdef ab abcdefghi abcde fghi ef abcde abcd abcdefgh j bce abcdef abcdef abcde abcdefghij et al. 2003). 41abc Overall performance. Hallmark, Pioneer L34HQ Yield 7034 6786 5439 6206 4542 7090 7310 6712 7318 6185 5400 6139 6619 6857 7452 6750 8149 6342 7841 6039 6517 6807 7053 6956 3730 6866 69 7510 6928 7717 3175

No significant differences. Sequel consistently showed good resistance 3 to PRR; it was either the most resistant (P<0.05) and Trifecta were significantly (P<0.05) more or equal to the most resistant on all occasions it persistent than CUF 101 and Hunter River, and Sens 1.22 0.82 1.11 1.79 0.89 0.92 1.11 0.47 0.45 0.87 1.3 1.53 1.19 2 -0.27 0.74 0.89 1.08 0.8 1.2 0.99 1 0.76 0.85 0.93 0.71 was assessed. Trifecta showed good resistance all other cultivars (Figure 4) were not different in 4 of 8 experiments. Other cultivars showing (P>0.05) from either of these groups. Hallmark,

Spring Aquarius, Aurora, Sceptre, Venus and Genesis abcde abcd ce h abcdef abcd abcd fg bdef def abcde a abcd ab abcdefgh abcd abd abcdef abcd ab abcd abcdef abcde abcdef def eg good resistance were: Pioneer 581 (1981, 1982 leaf spot complex. performed well under all environmental condi- and 1984), Sceptre (1986, 1989 and 1993), Hall- Yield 6493 6456 6064 3681 6370 6551 6590 5401 6021 5994 6376 7002 6562 6969 5240 6011 6377 6565 6120 5311 6467 6705 6545 6313 6571 6261 tions. WL 516, Pioneer L34HQ, UQL-1, Pioneer mark (1995) and Aquarius (1993 and 1995). The

1 581 and Sirosal could be expected to persist well best experimental line was at least equal to the only under favourable conditions while Pioneer Sens 1.03 0.72 0.26 0.84 1.07 1.41 0.91 1.2 0.56 0.44 1.6 3.58 0.47 1.3 0.64 1.1 1.27 1.13 1.13 1.57 1.05 0.97 1.02 1.05 0.66 1.29 1.43 best cultivar in all experiments except in 1981.

Leptosphaerulina L55, Hunter River, Pioneer L90, Pioneer L69 and / On the other hand, Hunter River always showed SARDI 10 handle unfavourable conditions better.

Winter little resistance to PRR. def efg j de abcdefghij bcdefg bcde bd ij h abcdefghij cefg abcdefg cefg fgh abcdefg bcd b bcde ghi ce bcdef bcdefgh abcdefgh a bcdefg j Individual experiment performance. Persist- Few cultivars showed resistance to the leaf ence varied substantially over the years, with the Yield 2805 2670 1052 2826 1989 2795 2856 3200 1654 2095 1165 2677 2647 3177 2714 2317 3052 3051 3167 3005 2138 2837 2841 2471 3059 3850 2776 Stemphylium disease complex of Stemphylium and Lept- 2 experimental general mean ranging from 29% osphaerulina. Aquarius, Quadrella, Trifecta and in 1984 to <5% for the 2 experiments in 1995 Hunter River were the most resistant. Condura (Table 6). Best persisting cultivars (i.e., culti- 4 r 73, Eureka, Pioneer 555, Stargrazer, UQL-1 and vars which have been either the most persistent Validor were equal to the best cultivar on the or equal to the most persistent entry) include Sens –sensitivity. Sens –sensitivity. Cultiva Aquarius Aurora Cimarron CUF 101 DK 187 Eureka Genesis Granada Hallmark Haymaker I Hunter River Matador Maxidor II Pioneer 581 Pioneer L34HQ Pioneer L52 Pioneer L55 Pioneer L69 Pioneer L90 Quadrella SARDI 10 Sceptre Sequel Sequel HR Sirosal Trifecta UQL-1 Venus WL 516 Best exp. exp. Worst

1 occasions they were assessed. Aquarius (twice from 5 experiments), Hallmark 14 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper 1998 2.66 3.10 1996 2.65 2.69 1995 2.78 2.64 3.18 2.81 1993 3.00 3.47 1989 2.81 2.50 2.78 Leaf disease complex ratings 1986 4.12 3.87 1 1981 3.39 3.50 4.59 4.06 4.40 4.07 4.53 4.39 3.29 4.23 4.29 4.22 4.40 4.36 3.93 4.18 3.76 4.31 4.04 1998 2.97 2.86 1995 1.86 3.29 2.29 3.62 1993 1.58 2.00 1.97 1.98 2.80 1.70 1989 1.76 2.72 2.39 1986 1.23 2.84 Phytophthora ratings 1984 1.31 1.78 1.00 2.39 1.30 1 1982 1.96 2.68 2.00 2.61 3.40 3.68 3.96 3.06 2.51 2.23 1 1981 2.78 3.33 2.45 2.47 3.16 2.58 2.54 2.98 3.83 2.44 2.47 2.44 2.42 2.73 2.26 3.16 3.15 3.65 2.31 2000 3.48 2.95 2.42 2.05 1.53 2.50 2.51 1996 2.07 2.18 1995 1.70 1.38 1.58 1.18 1989 2.03 2.01 2.47 1986 3.29 2.74 Colletotrichum ratings 1984 3.35 3.52 3.70 3.42 3.46 1 1982 1.87 1.93 2.23 1.55 2.10 1.57 1.67 1.90 2.12 1.92 1 1981 2.06 2.19 2.34 2.10 2.00 2.13 2.08 2.64 1.54 2.14 2.24 2.15 2.36 1.99 2.26 1.63 2.09 1.80 1.90 Level of damage caused by CCR (exhibited as anthracnose aerial lesions), phytophthora root rot and leaf disease complex, experienced during epiphytotics, at Gatton during 3-year Cultivar Aquarius Aurora Baron Cimarron Condura 73 CUF 101 Diamond DK 167 DK 185 DK 187 Eureka Falkiner Genesis Granada Hallmark Haymaker Haymaker II Hunter River Hunterfield Matador Maxidor I Maxidor II Megluce I Megluce II Nova Pioneer 532 Pioneer 555 Pioneer 577 Pioneer 581 Pioneer L34HQ Pioneer L52 Pioneer 54Q53 Pioneer L55 Pioneer L69 Pioneer L90 Table Table 5. experimental periods from sowings made between 1981 and 2000. Best and worst experimental lines provide the range of performance of breeding lines and differ from year to year. Evaluating irrigated lucerne in the subtropics 15 1998 2.15 2.39 2.00 2.90 2.63 0.44 1996 2.58 2.96 2.62 3.08 2.76 ns 1995 2.93 3.50 3.20 2.74 2.84 3.38 3.07 ns 1993 3.09 3.42 3.75 2.92 n/a n/a 3.25 0.25 1989 2.04 3.01 2.93 2.91 2.64 2.44 3.31 2.81 0.57 Leaf disease complex ratings 1986 3.65 4.26 4.62 3.61 3.32 3.84 3.99 2.75 3.18 4.54 3.80 ns 1 1981 3.82 4.24 3.90 4.31 3.22 4.35 4.46 3.75 3.80 4.11 3.13 4.46 4.05 0.63 1998 2.66 1.76 1.69 3.03 2.50 0.59 1995 2.76 2.14 3.29 2.55 2.24 3.24 2.75 0.58 1993 2.13 1.75 2.07 1.75 1.87 1.53 2.20 1.91 ns 1989 3.70 2.37 2.27 3.14 2.39 1.81 2.88 2.42 0.67 1986 1.29 1.07 1.19 1.08 1.25 1.30 1.21 1.80 1.05 1.46 1.27 0.61 Phytophthora ratings 1984 1.14 1.07 1.14 1.08 1.91 1.45 0.50 1 1982 2.00 3.22 2.65 1.82 3.46 2.69 0.60 1 1981 3.38 3.40 3.25 2.83 2.63 2.06 2.71 2.56 3.43 2.25 2.52 2.73 2.81 0.41 2000 3.08 3.08 2.44 2.87 1.55 2.31 3.31 2.58 0.68 1996 2.06 2.16 1.91 2.21 2.10 ns 1995 1.70 1.88 1.40 1.43 1.53 0.27 1989 2.04 2.06 2.08 2.17 1.99 1.88 2.75 2.26 0.32 1986 2.52 2.47 3.23 2.15 2.41 3.32 3.85 3.82 2.06 3.60 2.97 0.31 (1987a). Colletotrichum ratings 1984 3.61 3.29 3.15 3.27 3.90 3.53 0.32 et al. 1 1982 1.45 2.37 1.58 1.42 2.18 1.83 0.32 1 1981 2.28 2.53 2.41 2.29 2.43 1.74 1.99 1.88 2.13 1.75 2.10 2.10 0.35 2 Data reproduced from Lowe Best experimental line. Cultivar Quadrella Sapphire Sceptre Sequel Sequel HR Sheffield Siriver Siro Peruvian Sirosal Siro Tasman Springfield Stargrazer Trifecta UC Cibola UQL-1 Validor Venus Wakefield WL 320 WL 515 WL 516 WL 605 WL Southern Special Best exp. exp. Worst General mean LSD (P=0.05) 1 2 16 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper

Figure 4. The relationship between cultivar adaptation (regression coefficient = sensitivity) and cultivar mean persistence at the end of the 3-year evaluation periods for cultivars (+) and experimental lines (*) of lucerne. Cultivars with the same superscript are not significantly different at P=0.05.

(4 from 5), Hunter River (2 from 8), Pioneer 581 latter end of 3 years. Two older highly winter- (2 from 3), Pioneer L52 (2 from 2), Sceptre (2 active cultivars (Granada and Maxidor II) also from 6), Sequel (7 from 10), Trifecta (6 from 14) performed well in the third year, and were supe- and UQL-1 (2 from 4). The best experimental line rior to the better performing highly winter-active persisted as well as the best cultivar in 11 out of cultivars such as Sequel HR, Sequel, Sceptre, 15 experiments. Baron, Pioneer 54Q53, Queens- Pioneer L90, CUF 101 and SARDI 10, in some land 11, Sapphire and SARDI 7 were equal to the cases significantly so. best cultivar in the only experiment in which they appeared. Factors affecting 3-year yield and persistence

Percentage of total yield in the third year During the ‘normal’ period, environment accounted for 79% of the variation in 3-year Overall performance. Third-year performance yield. For the subset of data when PRR was is an indicator of how a cultivar performs at scored, the PRR rating explained 70% of varia- the end of the expected 3-year life of the stand. tion in yield over the 3 years. For the subset of Percentage of total yield in the third year was data when CCR was scored, CCR accounted for highest in Venus, Pioneer 581, Genesis, Pioneer 28% variation. Yield in Year 1 explained 36% of L55, Hallmark and Aurora (semi-winter-dor- the variation in Year 2 and yield in Year 2 only mant or winter-active cultivars) and these culti- 23% of that in Year 3. vars showed good long-term performance (Figure During the dry years, environment accounted 5). Hunter River showed yield improvement, rel- for 43% of the variation in 3-year yield. Yield ative to many better performing cultivars, at the in Year 1 explained only 16% of the variation in Evaluating irrigated lucerne in the subtropics 17

Figure 5. The relationship between cultivar adaptation (regression coefficient = sensitivity) and the percentage of total yield produced in the third year for cultivars (+) and experimental lines (*) of lucerne. Cultivars with the same superscript are not significantly different at P=0.05.

Year 2 and yield in Year 2 was not significantly Discussion correlated with that in Year 3. Persistence at the end of the third year in General the ‘normal’ period explained 23% of the variation in the percentage of total yield produced Australian-bred cultivars, particularly those selected specifically for the subtropical - envi in the third year, 17% of the variation in third- ronment of south-eastern Queensland, per- year yields and 17% of the variation in summer formed best. These are predominantly those bred yields. In the years when assessments were made, in Queensland [Trifecta, Sequel (Oram 1990), leaf disease rating explained 38.5% of the varia- Sequel HR (Bray and Irwin 1998), Hallmark tion in persistence, CCR (19%) and PRR (15%). (Bray and Irwin 1999) and UQL-1 (Irwin 2000)]; Multiple correlation including the factors Year 3 all were selected for disease resistance to CCR yields, spring yield and the leaf disease complex and PRR within the breeding programs. Aquarius accounted for 62% of the variation. In the dry (Waterhouse et al. 1993), Sceptre (Kobelt 1997), years, persistence was influenced by yield in Year SARDI 5 (Kobelt and Humphries 2007), SARDI 7 (Kobelt 2002), SARDI 10 (Kobelt 2006) and 1 (45% of the variation), % of yield in winter Venus (Williams 2003) came from other Aus- (36%), winter yields (32%) and % of the yield tralian programs but did have similar disease in the third year (25%). The multiple regression pressures exerted during selection. A number including summer and autumn yields and % of of cultivars imported from USA also performed yield in winter accounted for 68% of the varia- well. While many had been selected for disease tion. resistance, none was specifically tested against 18 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper 2005 7.7 21.1 2003 9.8 9.0 8.8 11.6 8.2 2001 7.1 5.2 2000 14.8 12.7 23.5 20.3 22.6 16.6 11.2 1999 22.8 16.8 1998 14.6 14.6 1997 25.9 24.6 31.3 27.9 1996 7.9 6.4 3 Persistence 1995 4.1 3.2 6.9 5.6 2 1995 3.3 4.6 8.5 4.5 1993 14.3 11.2 7.3 12.5 8.7 7.6 1989 11.1 12.6 14.0 1986 6.9 1984 24.9 25.8 25.3 18.2 32.6 1 1982 22.0 18.1 22.6 21.1 19.1 6.7 8.9 25.6 25.9 22.0 1 1981 29.1 25.2 21.1 18.2 21.0 23.1 21.4 18.4 11.7 20.4 16.6 20.6 19.4 17.1 22.1 16.7 16.0 20.7 23.4 Persistence (% occurrence), at the end of 3-year periods, of lucerne cultivars from sowings made annually from 1981 to 2005. Best and worst experimental lines provide the range of Cultivar Aquarius Aurora Baron Cimarron Condura 73 CUF 101 Diamond DK 167 DK 185 DK 187 Eureka Falkiner Generation Genesis Granada Hallmark Haymaker Haymaker II Hunter River Hunterfield Matador Maxidor I Maxidor II Megluce I Megluce II Nova Pioneer 532 Pioneer 555 Pioneer 577 Pioneer 581 Pioneer 5929 Pioneer L34HQ Pioneer L52 Pioneer 54Q53 Pioneer L55 Pioneer L56 Pioneer L69 Pioneer L90 Table Table 6. performance of breeding lines and differ from year to year. Evaluating irrigated lucerne in the subtropics 19 2005 31.2 9.6 11.3 20.5 13.6 13.7 21.6 2.2 14.5 7.3 2003 8.7 11.7 5.6 8.7 14.0 8.6 9.7 ns 2001 6.2 6.6 8.8 4.0 6.4 ns 2000 14.1 12.6 16.6 18.7 16.3 18.3 11.2 16.2 4.5 1999 19.3 24.2 30.8 8.9 20.4 4.7 1998 26.5 27.8 19.3 6.2 17.3 8.1 1997 13.3 28.6 31.8 34.8 26.1 16.9 23.6 7.0 1996 9.3 8.2 10.8 5.8 8.0 1.4 3 Persistence 1995 - - 4.9 1.2 2 1995 4.5 4.9 3.4 5.5 7.0 3.3 4.7 1.2 1993 10.5 12.7 12.6 9.5 12.9 15.0 6.4 10.0 4.4 1989 12.9 11.5 15.5 5.2 10.1 15.0 7.3 10.7 4.4 1986 15.7 26.3 14.7 15.4 14.1 20.5 17.4 10.8 28.9 12.8 18.6 9.8 1984 28.1 34.6 36.9 34.6 21.8 28.9 9.1 1 1982 26.5 17.6 26.0 26.5 18.3 20.7 4.6 (1987a). 1 et al. 1981 14.7 22.8 15.2 21.9 20.9 25.7 34.9 25.5 16.3 18.1 39.0 7.6 20.8 8.0 4 Different experiments conducted in the same year. Different Cultivar Quadrella Queensland 11 Rippa Sapphire SARDI 5 SARDI 7 SARDI 10 Sceptre Sequel Sequel HR Sheffield Siriver Siro Peruvian Sirosal Siro Tasman Springfield Stargrazer Trifecta UC Cibola UQL-1 Validor Venus Wakefield WL 320 WL 515 WL 516 WL 525 WL 605 WL Southern Special Best exp. exp. Worst General mean LSD (P=0.05) Data reproduced from Lowe Best experimental line. 1 2,3 4 20 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper

Australian races of the diseases before release. which were sprayed to control diseases (Irwin et Generally, the highly winter-active or winter- al. 2008). There was little evidence in our data active cultivars produced the highest yields in of any compensatory improvement in summer this subtropical environment in agreement with yields from less winter-active cultivars. Hum- other data collected in Australia (Humphries et phries et al. (2008) recommended that lucerne al. 2008; Irwin et al. 2008), although they did not growers continue to use highly winter-active cul- always persist as well as less winter-active mate- tivars in short-term (2–4 year) situations and our rial (Humphries et al. 2008; Boschma and Wil- data agreed with this recommendation for lucerne liams 2008). grown under irrigation in the subtropics.

Total yield Disease

The average production of the best cultivars While field assessment of lucerne disease is less (60–64 t/ha over a 3-year period) was similar reliable than laboratory measurements, because to that reported in central Queensland by Cam- it relies on severe epiphytotics which are rarely eron and Mullaly (1972) and central and southern evenly distributed across a lucerne stand, our data Queensland (Lowe et al. 1985; 1987a) and greater generally agree with the assessments of Irwin than that reported in southern states (Gault et al. (1974), Stovold and Francis (1988), Mackie and 1995). The decline in yield from 21 t/ha in the Irwin (1998) and Mackie et al. (2003). The dif- first and second years to 16 t/ha in the third year ferences between cultivars in field resistance contrasted with the increase in yields over time were greater for PRR than for anthracnose and recorded in more temperate areas (Gault et al. the leaf disease complex, which agrees with the 1995; Kelly et al. 2006). This suggests fewer above research. The lack of field data on many of diseases, lower disease pressures and therefore the newer cultivars is a limitation of this data set fewer plant losses in temperate areas relative to because epiphytotics did not occur from 2000 to subtropical conditions (Irwin 1977). 2006, owing to very dry conditions. Under such The proportion of total yield achieved in conditions, yield differences between susceptible the third year is important, especially in a sub- and resistant cultivars are much smaller, as dem- tropical environment, where most stands do not onstrated by the performance of the PRR-suscep- persist longer than 3 years. Generally in this tible line, Hunter River. Under minimal (2000) study, it was strongly related to persistence, few and moderate to high (1981–1993) disease pres- lines achieving more than 30%, with most highly sure, it yielded 96.5 and 65.7%, respectively, of winter-active cultivars below 28%. Such a meas- that of Trifecta. Generally, the data show that cul- urement may be less important in temperate tivars subjected to disease pressures during their regions, where plants survive longer than 3 years breeding and selection carry more resistance; for (Irwin et al. 2001). example, Trifecta has resistance to PRR and CCR, Sequel and Sceptre to PRR and Quadrella to the leaf disease complex. However, some appear to Seasonal performance have acquired resistance through natural selection pressures, i.e., the resistance of Hunter River Disease resistance is closely linked to the per- to anthracnose (Gramshaw et al. 1985) and the formance of a cultivar and it is often difficult to leaf disease complex (demonstrated from our distinguish between its effect and that of winter data), although it is susceptible to CCR (Irwin et activity level. For example, CUF 101 is as winter- al. 1980; Mackie and Irwin 1998). Differences in active as Sequel but its performance is reduced susceptibility to the leaf disease complex may be by susceptibility to anthracnose. Hallmark has an related to differential infection levels of the 2 dis- activity level of only 8 but performs as well as eases at the time of assessment; Quadrella was Sequel HR and SARDI 10, which are rated 9+. In selected for resistance to stemphylium leaf spot the subtropics, highly winter-active cultivars (8, and not to pepper spot (Leptosphaerulina trifolii) 9 and 9+) perform well in all seasons. This has (Bray and Irwin 1992). been demonstrated here and in a study of single Other factors can indiscriminately affect the crosses of disease-susceptible lucerne clones, performance of lucerne in the subtropics. While Evaluating irrigated lucerne in the subtropics 21 lucerne aphids (Therioaphis trifolii, Acyrthosi- better persistence as in other regions. Culti- phon kondai and A. pisum), leaf roller (Mer- vars such as Trifecta, Sequel, Hallmark, Sequel roophyas divulsana) and jassids did not cause HR and UQL-1 (activity levels 7, 9, 8, 9+ and major damage or were controlled by spraying, 7, respectively), demonstrated good resistance to the poorer performances in 1995 and 2005 were CCR and PRR, and appeared to also have added the result of white fringe weevil (Graphognathus resistance to unidentified factors in this environ- leucoloma) attack, which affected all entries and ment. Irwin (1977) and Irwin et al. (2004) sug- for which there was no effective control measure. gested that other root or crown diseases were Loss of most taproots resulted in little top growth present in eastern Australia and these cultivars following the attacks, although persistence was may inadvertently have been subjected to selec- less affected as adventitious roots replaced tap- tion pressures for these factors during field eval- roots. uation in their development. One such disease is aphanomyces root rot (Aphanomyces euthices), known to be present here (Othieno Abbo and Persistence Irwin 1990) and a major issue in the USA (Del- wiche et al.1987). Persistence is dependent on disease incidence and environmental conditions (abiotic stress) as well as activity level (Irwin 1977; Lowe et al. 1985; Techniques for evaluating lucerne under Humphries et al. 2008). The environmental effect subtropical conditions is explained in our study by the variation between years, in both the general mean and the perform- The long-term performance of lucerne under sub- ance of standard cultivars like Trifecta (Table 6). tropical conditions could not be reliably predicted In the worst year (1995), only 4.7% of the initial from our interrogation of factors affecting 3-year population survived for 3 years, which equated yield and persistence. However, the influence of to around 16 plants/m2, and, in the best year lucerne diseases (Irwin 1977) was strong; for (1984), 28.9% survived, equivalent to 55 plants/ the years between 1981and 1995 when we have m2. Although soils at the experimental site were PRR rankings, PRR explained 69.7% of the var- classified as black earths, there was some- var iation in the 3-year yield. CCR and the leaf dis- iation in clay content from site to site and this ease complex ratings influenced persistence more was reflected in the incidence of phytophthora strongly than yield (38.5 and 19.1%, respec- root rot. The best performance in 1984 was on tively). This agreed with research on American the lightest soil, in which there was little root dis- cultivars in Australia, which suggested that disease. ease had the greatest effect on persistence (Lowe The level of persistence after 3 years was et al. 1985). Aphids played no significant role in similar to experiences in other parts of Queens- the health of these aphid-resistant lucerne culti- land (Cameron and Mullaly 1972; Gramshaw vars. 1978) and southern Australia (Humphries et al. 2008). In most cases, the final population was about 20–40 plants/m2, suggested by Palmer and Future development of lucerne cultivars Wynn-Williams (1976) and Gramshaw (1978) as the minimum required before yield loss could be The performance of material from the gene pool expected. Cultivars with good resistance to CCR used to develop the current Queensland cultivars and PRR were most persistent in this subtropical appears to have reached a plateau with the per- environment. While cultivars with low activity formance of Sequel, and only very modest gains levels have normally been the most persistent in have been made with the more recently released other environments (Gramshaw 1978; Boschma cultivars. While UQL-1 has a very different and Williams 2008; Humphries et al. 2008), this genetic background from Trifecta and Sequel, was not evident under irrigated subtropical con- containing significant levels of M. sativa ssp. fal- ditions. Queensland-bred and tested cultivars cata in its genetic background (Irwin 2000), it were generally the most persistent in this envi- has not produced dramatic yield increases over ronment, although, in single experiments, cul- Trifecta and Sequel, as occurred when those cultivars with lower activity levels tended to show tivars replaced Hunter River. However, to date, 22 K.F. Lowe, T.M. Bowdler, N.D. Casey and P.M. Pepper we have utilised in Australian breeding programs Seeds Pty Ltd for both commercial seed and only a relatively small component of the world experimental lines. genetic variation that exists in lucerne (Irwin et al. 2001). Molecular genetics must play a role in the References future improvement of lucerne, with DNA Anon (2007) Standard tests to characterise alfalfa cultivars. markers linked to disease resistance and yield 3rd Edn. (Amended 2004). http://www.naaic.org/stdtests/ already identified in Queensland-adapted -mate index.html. Accessed 28/9/2007. (North American Alfalfa rial (Musial et al. 2005; 2006). We have worked Improvement Conference: Oklahoma, USA) Armour, D.J., Mackie, J.M., Musial, J.M. and Irwin, J.A.G. with the introgression of genes of M. sativa ssp. (2008) Transfer of anthracnose resistance and pod coiling falcata into M. sativa ssp. sativa (Mackie et al. traits from Medicago arborea to M. sativa by sexual repro- duction. Theoretical Applied Genetics, 117, 149–156. 2005) and single cross hybrids of M. sativa ssp. Boschma, S.P. and Williams, R.W. (2008) Using morpholog- falcata and M. sativa ssp. sativa (Irwin et al. ical traits to identify persistent lucernes for dryland agricul- 2008) with moderate levels of heterosis being ture in NSW, Australia. Australian Journal of Agricultural Research, 59, 69–79. obtained. While M. sativa ssp. falcata genes Bray, R.A. and Irwin, J.A.G. (1992) Register of Australian may have the potential to increase lucerne pro- herbage plant cultivars. b. Legumes 8. Lucerne (a) Medi- ductivity in this region, substantial breeding and cago sativa L. (lucerne) cv. Quadrella. Australian Journal of Experimental Agriculture, 32, 263. selection will be needed to achieve this. Such Bray, R.A. and Irwin, J.A.G. (1998) Register of Australian material is more likely to have a role in dryland herbage plant cultivars. b. Legumes 8. Lucerne (a) Medi- cago sativa L. (lucerne) cv. Sequel HR. Australian Journal grazing situations than under irrigation, where of Experimental Agriculture, 38, 209. biomass production is the major goal. Work is Bray, R.A. and Irwin, J.A.G. (1999) Register of Australian now in progress with crosses between Queens- herbage plant cultivars. b. Legumes 8. Lucerne (a) Medi- cago sativa L. (lucerne) cv. Hallmark. Australian Journal of land-bred material and highly winter-active Experimental Agriculture, 39, 643–644. lucerne material from Middle-eastern countries Cameron, D.G. and Mullaly, J.D. (1972) The performance and M. arborea (Irwin et al. 2008; Armour et al. of lucerne (Medicago sativa) lines in pure stands under irrigated and raingrown conditions in sub-coastal central 2008). These crosses are showing considerable Queensland. Australian Journal of Experimental Agricul- improvement (25% greater than Sequel) in yield, ture, 12, 646–652. Delwiche, P.A., Grau, C.R., Holub, E.B. and Perry, J.B. although they have large stems, poor leaf:stem (1987) Characterization of Aphanomyces eutiches isolates ratios and few branches per crown. With fur- recovered from alfalfa in Wisconsin. Plant Disease, 71, ther breeding, it should be possible to improve 155–161. Digby, P.G.N. (1979) Modified joint regression analysis for this material to create gains equivalent to those incomplete variety x environment data. Journal of Agricul- achieved by Sequel over Hunter River. tural Science (Cambridge), 93, 81–86. Finlay, K.W. and Wilkinson, G.N. (1963) The analysis of adaptation in a plant-breeding programme. Australian Journal of Agricultural Research, 14, 742–754. Acknowledgements Gault, R.R., Peoples, M.B., Turner, G.L., Lilley, D.M., Brockwell, J. and Bergersen, F.J. (1995) Nitrogen fixation The authors thank Mr Dave Schofield and the by irrigated lucerne during the first three years after establishment. Australian Journal of Agricultural Research, 46, staff at the Gatton Research Station for the day- 1401–1425. to-day management of the experiments and Mrs Gramshaw, D. (1978) A review of research on establishment, persistence and productivity of lucerne (Medicago sativa L.) Sandra Nolan for technical assistance. Funding to at Biloela from 1950 to 1975. Agriculture Branch Technical conduct the research has come from a number of Report No. 20, Queensland Department of Primary Indus- Rural Industry Research Funds through the South tries, Brisbane. Gramshaw, D., Langdon, P.W., Lowe, K.F. and Lloyd, D.L. Australian Research and Development Institute, (1985) Performance of North American and Australian The University of Queensland and the Depart- lucernes in the Queensland subtropics. 1. Field reaction to ment of Primary Industries and Fisheries and important root and crown diseases. Australian Journal of Experimental Agriculture, 25, 76–81. from various seed companies. The authors also Humphries, A.W., Zhang, X.G., McDonald, K.S., Latta, R.A. thank SARDI, the Department of Primary Indus- and Auricht, G.C. (2008) Persistence of diverse lucerne (Medicago sativa sspp.) germplasm under farmer manage- tries (NSW), CSIRO, Pioneer Seeds Pty Ltd, ment across a range of soil types in southern Australia. Aus- Pacific Seeds Pty Ltd, Wrightson Seeds Pty Ltd, tralian Journal of Agricultural Research, 59, 139–148. Seedmark Pty Ltd, Heritage Seeds Pty Ltd, Seed Irwin, J.A.G. (1974) Crown rot of lucerne in Queensland caused by Colletotrichum trifolii. Australian Journal of Genetics Australia, Australian Premium Seeds Experimental Agriculture and Animal Husbandry, 14, 197– Pty Ltd, Southedge Seeds Pty Ltd and Auswest 200. Evaluating irrigated lucerne in the subtropics 23

Irwin, J.A. (1977) Factors contributing to poor lucerne persist- in the subtropics. 2. Perennial grasses. Tropical Grasslands, ence in southern Queensland. Australian Journal of Exper- 42, 1–27. imental Agriculture and Animal Husbandry, 17, 998–1003. Mackie, J.M. and Irwin, J.A.G. (1998) The proportion of indi- Irwin, J.A.G. (2000) UQL-1. Plant Varieties Journal, 13 (1), vidual lucerne plants resistant to Phytophthora medicaginis 41–42. and Colletotrichum trifolii in Australian cultivars. Aus- Irwin, J.A.G., Lloyd, D.L., Bray, R.A. and Langdon, P.W. tralian Journal of Experimental Agriculture, 38, 41–44. (1980) Selection for resistance to Colletotrichum trifolii in Mackie, J.M., Musial, J.M., O’Neill, N.R. and Irwin, J.A.G. the lucerne cultivars Hunter River and Siro Peruvian. Aus- (2003) Pathogenic specialisation within Colletotrichum tri- tralian Journal of Experimental Agriculture and Animal folii in Australia, and lucerne cultivar reactions to all known Husbandry, 20, 447–451. Australian pathotypes. Australian Journal of Agricultural Irwin, J.A.G., Lloyd, D.L. and Lowe, K.F. (2001) Lucerne Research, 54, 829–833. biology and genetic improvement - an analysis of past activ- Mackie, J.M., Pepper, P.M., Lowe, K.F., Musial, J.M. and ities and future goals in Australia. Australian Journal of Irwin, J.A.G. (2005) Potential to increase yield in lucerne Agricultural Research, 52, 699–712. (Medicago sativa subsp. sativa) through introgression of Irwin, J.A.G., Mackie, J.M., Marney, T.S., Musial, J.M. and Medicago sativa subsp. falcata into Australian adapted Roberts, S. (2004) Incidence of Stagonospora meliloti and material. Australian Journal of Agricultural Research, 56, Acrocalymma medicaginis in lucerne crowns and roots 1365–1372. in eastern Australia, their comparative aggressiveness to Musial, J.M., Aitken, K.S., Mackie, J.M. and Irwin, J.A.G. lucerne and inheritance of reaction to S. meliloti in lucerne. (2005) A genetic linkage map in autotetraploid lucerne Australasian Plant Pathology, 33, 61–67. adapted to northern Australia, and the use of the map to Irwin, J.A.G., Pepper, P.M., Armour, D., Mackie, J.M. and identify DNA markers linked to resistance to Phytophthora Lowe, K.F. (2008) Use of single cross hybrids to measure megicaginis. Australian Journal of Agricultural Research, heterosis for yield in diverse lucerne genotypes growing in a 56, 333–344. subtropical environment. Australian Journal of Agricultural Musial, J.M., Lowe, K.F., Mackie, J.M., Aitken, K.S. and Research, 59, 999–1009. Irwin, J.A.G. (2006) DNA Markers linked to yield, yield Kelly, K.B., Stockdale, C.R. and Mason, W.K. (2006) The components, and morphological traits in autotetraploid productivity of irrigated legumes in northern Victoria. 1. lucerne (Medicago sativa L.). Australian Journal of Agri- Effect of irrigation interval. Australian Journal of Experi- cultural Research, 57, 801–810. mental Agriculture, 45, 1567–1576. Northcote, K.H. (1971) A factual key for the recognition of Kobelt, E. (1997) Sceptre. Plant Varieties Journal, 10 (2), 57. Australian soils. (Rellim Technical Publications: Glenside, Kobelt, E. (2002) SARDI Seven. Plant Varieties Journal, 15 South Australia). (2), 43–45. Oram, R.N. (1990) Register of Australian herbage plant culti- Kobelt, E. (2006) SARDI Ten. Plant Varieties Journal, 19 (3), vars. (CSIRO: Melbourne, Australia). 188–194. Othieno Abbo, E. and Irwin, J.A.G. (1990) Aphanomyces Kobelt, E. and Humphries, A.W. (2007) SARDI Five. Plant eutiches, a possible cause of poor lucerne establishment in Varieties Journal, 20 (1), 254–259. Queensland. Australian Journal of Experimental Agricul- Lloyd, D.L., Gramshaw, D., Hilder, T.B., Ludke, D.H. and ture, 30, 361–364. Turner, J.W. (1985) Performance of North American and Palmer, T.P. and Wynn-Williams, R.B. (1976) Relationships Australian lucernes in the Queensland subtropics. 3. Yield, between density and yield of lucerne. New Zealand Journal plant survival and aphid populations in raingrown stands. of Experimental Agriculture, 10, 71–77. Australian Journal of Experimental Agriculture, 25, 91–99. Payne, R.W., Harding, S.A., Murray, D.A., Soutar, D.M., Lowe, K.F., Gramshaw, D., Bowdler, T.M. and Ludke, D.H. Baird, D.B., Welham, S.J., Kane, A.F., Gilmour, A.R., (1985) Performance of North American and Australian Thompson, R., Webster, R. and Tunnicliffe Wilson, G. lucernes in the Queensland subtropics 2. Yield and plant (2007) The Guide to GenStat Release 10, Part 2: Statistics. survival in irrigated stands. Australian Journal of Experi- (VSN International: Hemel Hempstead). mental Agriculture, 25, 82–90. Peace, C. (2007) Australian fodder production by year. In: Lowe, K.F., Gramshaw, D., Bowdler, T.M., Clem, R.L. and (Copyright © 2002 Australian Fodder Industry Association Collyer, B.G. (1987a) Yield, persistence and field disease Inc. http://www.afia.org.au/information/statistics/, Updated assessment of lucerne cultivars and lines under irrigation in 1 March 2005, Accessed 28/9/2007) the Queensland sub-tropics. Tropical Grasslands, 21, 168– Stace, H.C.T., Hubble, G.D., Brewer, R., Northcote, K.H., 181. Sleeman, J.R., Mulcahy, M.J. and Hallsworth, E.G. Lowe, K.F., Langdon, P.W. and Bowdler, T.M. (1987b) Com- (1972) A handbook of Australian soils. (Rellim Technical bined effects of leaf spot diseases caused by Stemphylium Publications: Glenside, South Australia) vesicarium (Wallr.) Simmons and Leptosphaerulina trifolii Stovold, G.E. and Francis, A. (1988) Incidence of Colletotri- (Rostr.) Petr. on lucerne cultivars, and the efficacy of some chum trifolii on lucerne in New South Wales, its host range fungicidal control methods. Australian Journal of Experi- and reaction of lucerne cultivars to inoculation. Australian mental Agriculture, 27, 59–65. Journal of Experimental Agriculture, 28, 203–210. Lowe, K.F., Bowdler, T.M., Casey, N.D., Lowe, S.A. and Waterhouse, D.B., Williams, R.W. and Oram, R.N. (1993) Pepper, P.M. (2007) Evaluating temperate species for the Register of Australian Herbage Plant cultivars. b. Legumes subtropics. 1. Annual ryegrasses. Tropical Grasslands, 41, 8. Lucerne (a) Medicago sativa L. (lucerne) cv. Aquarius. 9–25. Australian Journal of Experimental Agriculture, 33, 257– Lowe, K.F., Bowdler, T.M., Casey, N.D., Lowe, S.A., White, 258. J.A. and Pepper, P.M. (2008) Evaluating temperate species Williams, R.W. (2003) Venus. Plant Varieties Journal, 16 (3), 43–45.

(Received for publication January 19, 2009; accepted February 12, 2009)