Yellow serradella

Yellow serradella
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NOTE: The information in this Agnote must be read in conjunction with Introduction to selecting and using pastures in NSW, which covers information on areas of adaptation, sources of variability, species mixtures, and important issues related to animal health and the conservation of native vegetation.

Pasture type and use	Annual hard-seeded legume, with main growth in autumn, winter and spring. Mainly used as a pasture plant, and suited for grazing, hay or silage. Particularly tolerant of acid soils, and a deeper rooting system than that of sub clovers makes it more productive on deeper light soils.
Area of adaptation	North and Central Western Plains, North West Slopes, Central West Slopes, South West Slopes, Northern Tablelands, Central Tablelands, Southern Tablelands, and in well-drained light soil in coastal districts.
Min. average annual rainfall	400 mm (northern NSW) to 350 mm (southern NSW). Also suited (given suitable soils) to medium and high rainfall areas.
Advantages	A nutritious, palatable, persistent legume. Deep-rooted, able to root much more deeply than sub clover. Low bloat risk. Extremely tolerant of aphids (unlike sub clover). Can tolerate heavy grazing; however, it is important not to graze too hard during flowering, especially until seed reserves have built up. A very high level of hard seed, ensuring protection against false summer and early autumn breaks. Compatible with summer-growing perennial grasses such as consol lovegrass, Premier digit grass and Rhodes grass. Can compete well with weeds. Makes good quality hay and silage. Contributes to soil nitrogen. Reasonable seedling vigour, and some tolerance to redlegged earth mites and blue oat mites. Tolerates high levels of soil-available aluminium, and low pH (however, will respond to lime in very acid soil conditions). There are a number of suitable herbicides for weed control.
Disadvantages	Not suited to clay or clay loam soils. If autumn breaks are late, early growth can be slow. Does not suit heavy grazing following a long rest period if plants have grown to 10 cm or so in height. Being an annual, requires companion summer-growing species for all-year-round paddock production. Requires good soil fertility for best production. Early establishment can be slow if sowing with ‘hard seed’ and conservative sowing rates. Does not suit prolonged waterlogged conditions. Susceptible to pests such as lucerne flea and heliothis.
Soil requirements	Best on deep (> 60–80 cm) well-drained lighter to medium loam soils. Can tolerate aluminium up to 35% of CEC (cation exchange capacity) — some variety differences. Will also grow on soil with pH up to 7.0, but beyond that, not known. Soils that set hard (e.g. sodic) don’t particularly suit serradella. For adequate growth, soil fertility deficiencies such as phosphorus, sulfur and molybdenum need correction.
Varieties	Select on the basis of maturity, hard-seed levels and tolerance to soil aluminium. Mid–late season, high hard-seed levels: Avila Early–mid season, high hard-seed levels: Elgara — seed may be in short supply. Madeira Early season, medium hard-seed levels: King Early season, high hard-seed levels: Santorini * Charano * Very early season, high hard-seed levels: Yelbeni * * Denotes that this variety is protected by Plant Breeder’s Rights.
Sowing rates:	Often sow serradella with other legumes (e.g. sub clover), because of soil type variability over a paddock. Generally sow two or more varieties to cater for variable seasons and conditions. Seed is of variable quality. High quality dehulled seed, sow at 1–3 kg/ha. Partially dehulled seed (enhanced), sow at 2–6 kg/ha.
Sowing time	Autumn, late March through to early June.
Companion species	Other winter legumes on variable soil paddocks, and a summer-growing perennial species (e.g. consol lovegrass).
Inoculation	Group G. Lime pelleting is desirable.
Major nutrient deficiencies	Phosphorus, sulfur, molybdenum, and occasionally potassium.
Main insect pests	Blue oat mite (some tolerance), redlegged earth mite (some tolerance), lucerne flea, vegetable weevil, jassids, Heliothis punctigera (native bud worm).
Main diseases	Very few disease problems yet observed. Potential diseases include brown leaf spot (Pleiochaeta setosa), grey mould (Botrytis cinerea), anthracnose, and cercospora fungus.
Management	Suited to moderate set stocking, as well as various rotational grazing practices. However, is often severely damaged if heavily grazed following a long period of regrowth resulting in rank growth. It is important to graze down dry summer material by early autumn to around 1–1.5 t/ha dry matter to encourage good autumn germinations.
Livestock disorders of particular note	No problems reported.
Additional tips	Establishment is possible from a variety of techniques, including topdressing, direct drill, and full seedbed preparation. Placed seed, shallow in the soil where weeds are controlled, will generally ensure faster establishment.
Further information	Agfact P2.5.23 Serradella. Weed Control in Lucerne and Pastures 1998/99.

Acknowledgments

Advice on livestock health disorders was provided by Dr Chris Bourke, Principal Research Scientist, NSW Agriculture, Orange. His contribution is gratefully acknowledged.

Photo: Warren McDonald, Former Technical Specialist (Pastures), NSW Agriculture, Tamworth.