Protected Solidago Production

Transcription

1 Cut Foliage Fact Sheet No Protected Solidago Production Protected Solidago Introduction Production Solidago or golden rod (Family Asteraceae) is a common herbaceous perennial, widely distributed which grows as a wild flower in North America, Asia and Europe. It also makes an excellent cut flower/filler in mixed flower bouquets and is demanded all year round by flower bouquet processers. Trial work was carried out on the species in Kildalton Horticultural College, Co. Kilkenny in 2012 both under protection and out of doors. The following note describes production experience with the species under protection to date. Varieties & continuity Early season -Tiara Main crop -Tara Gold Late - Autumn Glow In protected production, continuity is achieved by varying the cultivar and time of pinching (taking out the leading shoots). By later pinching you extend the season. Trials conducted on the cultivar Tara Gold in Kildalton College during 2012 resulted in 2 crops produced under protection in a cold glasshouse. Long day length (16 hrs) is necessary during the vegetative phase. By manipulation of lighting and by adding heat, further crops are possible. Further trials work on continuity of production and season extension will take place during 2013.

2 Page 2 Propagation of plant material Traditionally, propagation is carried out by division. This may be done in autumn or spring and small plants of 2 or 3 growths are suitable for use in bulking up stocks. Propagation can also be made through tip cuttings in the late spring/early summer period. The cultivars used for commercial production are generally supplied from specialist propagators in Holland and are available year round and are subject to payment of royalties. Soil Solidago is easily cultivated and has no major special requirements. A good free draining medium or sandy loam soil is ideal. Ph 5-7 Planting Experience to date suggest the crop should be planted in the spring of the year to allow it to get well established so that good crops are produced in the second and third year. Depending on planting date, a partial crop can be harvested in the first year with at least up to 2 crops possible annually thereafter. Continuity of production late May to late September is possible. The plants should produce for at least 3 years after which time they are generally replaced. Plant density A spacing that will give 12 plants m² or 90,000/ha (37,000 /acre) allowing room for paths to facilitate operations such as spraying and harvest is recommended. A layout with closer spacing in the outside rows is ideal (see picture). Support wires are recommended to help maintain stem quality as the crop grows.

3 Page 3 Irrrigation & Nutrition Even watering is very important. Be careful with watering in flowering phase as too much may cause side shoots to grow and overtake the flower spike. On the basis of a soil analysis, apply a base dressing to ensure Phosphorus & Potash levels are adequate. Responses occur if Nitrogen is added. A standard foliar feeding regime of is usually adequate. Feeding is necessary 1-2 times per week when the crop is actively growing provided via layflat drip irrigation system. The crop is susceptible to Magnesium deficiency. Epson salts as a liquid feed maybe necessary if the inter-veinal chlorotic symptoms begin to show on the older leaves. Weed Control While there are residual herbicides safe to use on the crop, it is recommended that the soil is sterilised prior to planting or alternatively plant through a light guage plastic mulch or other similar barrier. Pest & Disease Control The standard pests of protected crops such as thrips, whitefly and spider mite need to be watched for. Monitoring using sticky traps is recommended and action should be taken if necessary. Caterpillars and slugs can occasionally be problematic. Solidago can be susceptible to powdery mildew & rust so a spray programme must be implemented. This programme should commence early as powdery mildew (pictured) can spread very quickly, from lower leaves to upper parts and also through the crop. Avoid prolonged periods of high humidity to lessen the risk of rapid disease development. A number of fungicides are recommended for disease control including Systhane, Bumper & Signum. Contact your adviser for up to date control measures and the recommended pesticides.

4 Page 4 Harvesting The first flush of stems are normally ready for harvest in late May/early June depending on the variety. Sequential harvests can take place weekly thereafter until late Autumn. It usually takes weeks from start of growth to harvest stage. Picture shows the crop close to harvest with the ideal harvesting stage being when the first few flower buds are just beginning to open. The spikes of flowers should be cut as soon as ready as browning of the flowers occurs soon after they are fully opened and this spoils the appearance of the spikes. Aim to complete harvesting of scheduled beds within a week to 10 days. Bunching can be done either directly as the crop is harvested or alternatively in a separate operation where spikes can be rough cut and graded and bunched in the shed. A treatment of at least 4 hours with a bactericide (Florissant 200: 2 mls /lit of water) will increase the post harvest durability. Ideally cold storage of stems to maintain quality after harvest and prior to transport to market is necessary. Cutting back As the plants get older, they tend to produce more stems per plant, though the stems are thinner and of lower quality. After harvest, ensure you cut back to within a few cm s of ground level, leaving 3-4 pairs of leaves. Any loose leaves and stems should be removed and discarded. Costs & Returns Table 1 shows the likely costs and returns from an indoor crop based on 2 main harvests per year. At a planting density of 12 plants per sq metre. a yield of at least 1.44 million stems/ ha per year (at 8 stems per plant) is achievable from the second year onwards. From an initial investment of approximately 30,000 per ha, a gross return of 100,800 per ha is

5 Page 5 achievable. Net return depends on growers involvement as most of the cost is labour for harvest. When labour for harvest and maintenance is included, a net return of over 40,000 per ha per annum is achievable. Table1. Costs and returns of 1 ha of Solidago cut filler Establishment Year 1 per ha Ground Preparation 500 Base Fertiliser 300 Plants 30ct) Planting 2000 Weed Control 400 Total Establishment cost Return from Year 2 Annual yield/ha million ct Harvest/cold 4 ct/stem ct/stem 2880 (weed, pest & disease control, nutrition, cutting back/clearing) Net annual return/ha Assumptions - Irrigation & support framework systems in place. With thanks to Grainne Mc Mahon & staff at Teagasc, Kildalton Horticultural College, Piltown, Co. Kilkenny for help with trials work. For further information contact Andy Whelton Teagasc Horticultural Development Unit. Tel: