Botanical name: Leptospermum rotundifolium Cultivar: Lavender Queen Quality specifications for Australian wildflowers
Botanical name: Leptospermum rotundifolium Cultivar: Lavender Queen Leptospermum is an attractive feature filler from the Myrtaceae family, to which waxflower belongs. It has similar postharvest handling requirements to waxflower. Stems bear numerous flowering branchlets, each with dense masses of 5-petalled flowers 20 to 25 mm across, with a nectar-filled central hypanthium (the floral structure consisting of the bases of the sepals, petals and stamens fused together). Lavender Queen flowers are a striking mauve. The reddish-brown buds are another attractive feature. The small rounded leaves are an attractive, fresh, mid green. As they mature, flowering stems bear a range of flowers of different maturities, ranging from the youngest at the top to the oldest at the base. For optimum quality, it s important to pick stems to suit the buyer s requirements. For export, pick with most of the buds about to open and fewer than 25% of flowers open at the base of the stem. For domestic sales, stems with up to 50% of the flowers open are preferred. Rapid postharvest handling and marketing are critical. Vase life is extended if stems are recut and placed in deep water (20 cm) by the end user to maintain good water uptake. Several breeding programs have produced a range of superior new cultivars with flower colours ranging from white through pale to hot pink to red and purple and bicolours. Many of these are protected by Plant Breeder s Rights. Of the new selections, Cherish, Tickled Pink, Rhiannon, Outrageous, Aphrodite and Rudolph are available now, and others will become available in the near future. The flowering season of each Leptospermum selection is generally 2 weeks. These new selections will extend the overall flowering season from late August until early January. Plants will produce marketable yields after 18 months. Regular irrigation will promote long stems. Flowers are borne on the current season s growth. Heavy pruning after flowering promotes long stems for the next year and minimises problems such as woodiness and the incidence of pests such as borers and leafwebbing caterpillars. It is important to prune off stems with seed capsules from the previous year s flowers so they are not on next season s flower stems. Different Leptospermum species and selections seem to be variable in their postharvest life and the degree to which they suffer from petal drop and flowers drying out. For example, L. scoparium hybrids have only a few days vase life. This may be related to their sensitivity to external and possibly internal ethylene, which causes petals, individual flowers and leaves to drop, or makes petals close up or dry up. Flower drop appears to be most obvious if flowers are in high humidity, e.g. in a package. These effects can make the product unsaleable. Lavender Queen is susceptible to petal drop, both naturally and in response to ethylene, as are L. morrisonii (green-leaved Queensland form), L. petersonii and L. scoparium hybrids. Sources of external ethylene include engine exhaust fumes, ripening fruit and vegetables, and some flowers, especially if they are stressed or diseased (e.g. infected with botrytis). Anti-ethylene treatments during postharvest processing are effective at reducing flower loss. Some selections of Leptospermum are marketed for their attractive foliage of varying shades of green and red, and some are used when in bud. Flowering season: September October (but soon to be extended). Typical vase life: 7 10 days. Export can greatly reduce the vase life, especially if the transport conditions are not cold, the product dries out, or transport takes too long. Other products to which this specification can be generally applied: Selections and cultivars of Leptospermum. New cultivars of Leptospermum are becoming available; for example Cherish.
STAGes of OPenING The stages shown apply to the product at market entry. Pay attention to the weather, time of year, and mode and duration of transport, because the flowers will continue to open during transport. You must consult with your target market to ensure that the flowers arrive at the desired stage. Stage 1 Immature stage flower buds cracking but no colour visible: unacceptable to markets Stage 2 Slightly immature most flower buds cracking and <25% of flowers open: early stage, preferred by only a few markets (e.g. export) Common defects Common defects to avoid at market entry: n Overmature flowers n Presence of insects n Nuts on marketed stems n Yellow foliage n Bent stems n Sparsely flowering stems n Grow-through n Excessive foliage in relation to flowers Overmature flower (close up) avoid marketing stems with senescing flowers Nuts from previous season present on stem (remove when bunching) Yellow foliage avoid by managing crop nutrition before harvest Webbing caterpillar do not harvest (avoid by managing insect pests before harvest) Too much grow-through and excessive foliage in relation to flowers (cultivar other than Lavender Queen shown)
Stage 3 Prime stage for domestic markets 50% 75% of flowers open Stage 4 Mature stage all flowers open: suitable for immediate retail use, as lowest flowers are already starting to shrivel Stage 5 Overmature stage most flowers fully open and some shrivelling: not accepted by markets Series of flower buds from fully closed to overmature (maximum stage of any flower on a marketed stem is 3 4 for export and 5 6 for domestic markets) 1 2 3 4 5 6 7 8 Stem too bent do not harvest Sparsely flowered stem do not harvest (cultivar other than Lavender Queen shown) Top of bunch not protected by sleeve (cultivar other than Lavender Queen shown) Typical bunches look like this
FLOWERS Appearance When to harvest Colour clear and uniformly mauve; true to type of Lavender Queen. Flowers clustered densely and evenly along and around the flowering branchlets on the stem. Stem well branched (bearing many flowering branchlets) and balanced. Not dull or dried out. No wilting. No flower drop. When lower flower buds are cracking and mauve is visible, and up to 25% of flowers are open (stage 2) for export, or when 50% 75% of flowers are fully open (stage 3) for domestic markets. Avoid harvesting when flowers are wet. RECOMMENDED HANDLING AT HARVEST During harvest, minimise drying out and exposure to heat. Preferably pick into deep (20 cm) postharvest or hydrating solution. Transport to a cool, shaded packing shed in <1 hour. Hold flowers under conditions of high humidity and avoid too much air movement over the flowers (to avoid petals shrivelling). Handle stems carefully, as petals fall off easily. GRADING AND BUNCHING Grading Reject any contaminated stems. Remove seed capsules from the previous year s flowers. Sort stems according to flower maturity, length and thickness. Damage Contamination Pests and diseases LEAVES Appearance <5% of flowers deformed or damaged (including mechanical damage and discoloured petals). No shrivelling or curling of petal margins, which indicates overmaturity. Product free of grit and soil, weeds or weed seeds, living or dead insects, and signs of insects or spiders, such as webbing. No insects, insect damage or disease. Fresh, crisp appearance; uniformly mid green; no yellowing. No leaf drop. Stem length Bunching Stems per bunch 50 80 cm (measure from base to the top flower). Flowering stems are marketed in bunches. Bunch size depends on market demand. The number of stems per bunch varies, and is determined by their length and by market and buyer requirements. Presentation is important. Stay consistent for the grade and make all bunches the same. Use 2 ties, 1 near base (3 cm from bottom) and another 12 cm from the base. Two ties make it easier to pack. Especially for export, stems should be approximately the same diameter within a bunch, with the ends aligned. Different markets require different bunches broadly: Stem length Av. no. of stems per bunch At harvest There is no need to remove leaves from the lower stem. 80 5 Damage STEMS Appearance Length <5% of leaves damaged. Minimum evidence of pests, such as webbing or borers, and disease. Other blemishes <5%. Free of visible chemical residues. Rigid and strong enough to support blooms, without being too woody and bulky. Bend <30. No awkwardly branched stems. No significant grow-past, where the shoots at the stem tip grow through the flowers: maximum 3 5 cm soft tip growth beyond flowers (soft tips will wilt after harvest). No seed capsules from the previous year s flowers. Free of disfiguring trim marks or other blemishes. Neatly cut end. According to market demand. Sleeves HOLDING AND STORAGE Cooling 60 70 cm 5 50 cm 5-10 Use sleeves to protect the product. A tight sleeve holds the bunch together and makes flowers easier to pack. Effective cooling soon after harvest is important to retaining quality and maximising vase life. There are two options: Cool, process, cool for example, remove field heat by cooling flowers immediately on entry into shed to 10 C in buckets of solution, process flowers (bunch, grade), and then cool to 2 4 C by either forced-air cooling (if boxed) or holding overnight in a cool room. Process within 1 hour of cutting, and then cool to 2 4 C by either forced-air cooling for 20 30 minutes (if boxed) or holding overnight in a cool room (if in buckets). Forced-air cooling of packed flowers is the preferred option to achieve rapid cooling and marketing.
HOLDING AND STORAGE cont d Temperature and humidity Anti-ethylene treatment Postharvest solutions Longer-term storage PACKAGING If necessary, hold in a high-humidity cool room (95%) at 2 4 C until ready to process. Another way of achieving high humidity is to cover the flowers with plastic sleeves or plastic sheeting. Anti-ethylene treatment is recommended for Lavender Queen. There are two alternatives: 1. Use a commercial anti-ethylene silver solution, e.g. Chrysal AVB. Prepare solutions according to the manufacturer s instructions (for more details, refer to the Postharvest Manual*. Treat bunches according to the product label (concentration, temperature and duration of treatment). Uptake may be less effective if flowers are poorly hydrated before pulsing. Check uptake by your flowers as described in the Postharvest Manual* and do your own trials to optimise the procedure: over-pulsing can have adverse effects (e.g. rapid closing and shrivelling of flowers). 2. Alternatively you can add EthylBloc anti-ethylene sachets to cartons when the flowers are packed (see Packaging below). Postharvest solution: If necessary, hold the flowers in deep (20 cm) clean water with a reputable commercial postharvest or hydrating solution or a registered biocide. If the flowers have dried out after harvest it may be necessary to recut the stems (5 cm) before placing them in postharvest solution. Holding solution: Same as postharvest solution. For longer storage seek professional advice, and test in the market before committing product. Pack bunches of similar size (stem number, weight or thickness) together. Put bunches of similar length together, and ensure all bunches meet this specification. Pack boxes according to customer requirements. Pack bunches firmly but springy so the product will not move and be damaged. But packing too tightly can damage flowers during transit. Pack bunches head to tail. Use boxes with holes to allow forced-air cooling if necessary. Do not line boxes with plastic, as this will increase humidity and the risk of botrytis. Use paper if desired. Leave ventilation holes open to reduce humidity, ethylene build-up, botrytis growth and flower drop. If EthylBloc anti-ethylene treatment is required, add the sachets to the cartons according to the manufacturer s instructions when the flowers are packed (efficacy may vary depending on packing situation). Cool flowers to 2 4 C before transport. LABELLING AND DOCUMENTATION Label boxes or buckets as recommended in Postharvest Manual* or as required by customer. Ensure that box contents are exactly the same as specified in the documentation and on the end of the box. TRANSPORT Refrigerated vehicle, preferably at 2 4 C, but not 0 C. Preferably don t transport with ripening fruit. COMMON POSTHARVEST PROBLEMS Refer to Postharvest Manual* for general advice. Fungal decay in storage due to botrytis (grey mould) Insects (for export) Ethylene sensitivity and antiethylene treatment Because flowers infected with botrytis can produce ethylene, effective preharvest management with fungicides is essential, especially within the 2 weeks before harvesting. Effective management of insect pests before harvest is essential, especially within the 4 weeks before harvesting. Use preharvest insecticide sprays to reduce the pest population at harvest. Dip flowers that are to be packaged and held for any significant length of time (e.g. exported) in a registered fungicide and insecticide solution with added wetting agent for not less than 1 minute, then dry naturally for 2 hours to ensure thorough disinfestation. Alternatively, fumigate with a registered insecticide with stems in water containing a postharvest or hydrating solution or registered biocide. Lavender Queen is highly sensitive to external and possibly internal ethylene, which causes flower drop, and anti-ethylene treatment is required. See Anti-ethylene treatment opposite. Messages for importers and wholesalers n Recut stems and place into deep (20 cm), fresh water containing a reputable commercial postharvest solution, registered biocide or flower food. n Cool product before marketing or sending on and keep it cool and dry. n Maintain good hygiene and keep containers clean. Messages for retailers n Recut stems and place into deep (20 cm), fresh water containing cut-flower food or a registered biocide. n Use clean buckets and containers for displays. n Do not display flowers in areas that are exposed to full sun, draughts, high temperatures or vehicle exhausts, and preferably do not display near fruit and vegetables. Use refrigerated displays if possible. n Tell the customer how to care for the flowers and emphasise the need for cut-flower food in solutions. Give the customer a sachet of cut-flower food to take home. Messages for consumers n Keep vase filled with the correct solution of cut-flower food. Check daily, as flowers can use a lot of water. If-flower food is not used, change the water at least every second day. Always use clean vases and clean water. n Do not display in areas that are exposed to full sun, draughts or high temperatures. Keep as cool as possible without freezing. JN:9991 Layout by Wild Poppy Design Edited by Matthew Stevens, ScienceScape Editing, Sydney SUPPORTING INDUSTRY PARTNER: Authors: Bettina Gollnow and Dr John Faragher. Photographs by: Dr Ross Worrall and Lowan Turton. This publication is one of a series of Quality Specifications for Australian Wildflowers. ISSN 1440-6845. ISBN 978-1-74254-016-0. RIRDC Publication No. 10/043. www.rirdc.gov.au *The Postharvest Manual is the manual Postharvest Handling of Australian Flowers from Australian Native Plants and Related Species, 2nd edition, 2010. ISBN 978-1-74254-000-9. RIRDC Publication No.10/027. Both publications were developed by RIRDC Project No. PRJ-000331. The information contained in this publication is intended for general use to assist public knowledge and discussion and to help improve the development of sustainable regions. You must not rely on any information contained in this publication without taking specialist advice relevant to your particular circumstances. 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