Production and flowering of Babiana ringens corms was assessed in three experiments. Flowering performance of nine corm weight grades (0.03, 0.12, 0.24, 1.0, 3.1, 5.2, 7.0, 9.1, 11.0 g), corm production from seed sown in a greenhouse and outdoors from December to May was assessed, as well as the effect on corm growth of three planting densities (112, 224, and 336 corms/m(2)) in the greenhouse, or outdoors. All corms >= 1 g flowered. The time to flowering for plants grown from corms >= 3 g averaged 153 days. However, the time to flowering increased for lower corm weights. The minimum corm planting weight for consistent forcing was >= 3 g. Seed germination was high for sowing dates from December to April, with an average germination rate of 75%. Corm weights were higher for plants grown from outdoor than greenhouse-grown seed, with corms reaching 2.4-2.9 g in the first year. When seed-derived corms were grown for a second season, all plants reached a flowering size. For outdoor grown plants a mean lifted corm weight of 10.4 g was achieved across all densities.

The effects of bulb storage duration and temperature on the flowering of greenhouse-grown Lycoris aurea were assessed in two experiments. In 2004/05 lifted bulbs were stored at 22, 25 or 28 degrees C for 92 days, or non-lifted bulbs were stored at 25 degrees C for 0, 40, 60, 80 or 100 days. Increasing storage temperatures of lifted bulbs delayed flowering by up to seven days and increased stem length by greater than 150 mm. Storage durations of non-lifted bulbs of 40-60 days advanced the flowering date by up to 10 days, and had no effect on cut stem length and yield.

The effects of wounding of calla (Zantedeschia spp.) tubers ('Black Magic'), inoculation of plants with Erwinia carotovora subsp. carotovora (Ecc), water-logging of plants, and temperature of planting media on the incidence of calla soft rot was investigated under controlled conditions in the greenhouse in two seasons. The highest disease scores occurred in plants at 28 degrees C that had been wounded, inoculated with Ecc, and water-logged, whereas the lowest disease scores occurred in plants at 24 degrees C that were not wounded, not inoculated with Ecc, and not water-logged. The major treatment effect was that of temperature with plants subjected to 28 degrees C having significantly (P<0.001) higher levels of rot than plants at 24 degrees C. Wounded plants had significantly higher mean disease scores than non-wounded plants, although wounding had less of an effect on disease severity than did temperature. Inoculating with Ecc and water-logging the soil also both increased the disease score but only to a small extent in comparison with the temperature and wounding treatments. The study clearly demonstrated that calla soft rot caused by Ecc was favoured by wounding of plant tissue, and infection was greatly enhanced under conditions that impaired host resistance (anerobic conditions caused by water-logging) and favoured bacterial development (28 degrees C that is optimum for bacterial multiplication).

The effects on the cut flower production of three populations of Sandersonia tubers with different storage durations (lifted 1 May, 1 July and 1 September) were assessed over seven planting dates (between 1 September and 30 March). Stem length declined with planting dates from 1 September to 15 December, but increased with subsequent plantings. Mean air temperature was greater in mid-summer and was the main cause of declining stem lengths in the September to December plantings. Time from planting to harvest declined with later planting dates from September right through to late March, and was not significantly influenced by differing storage durations for a given planting date. Carbohydrate concentrations in the tubers were analysed before and after storage; tuber sugar levels increased consistently during storage. The reasons for these changes are discussed.

Vase solutions of 2.5 or 5% (w/v) sucrose markedly reduced the abscission of all open florets and buds on cut Agapanthus praecox stems. Pulsing cut stems with these solutions was not as effective as continuous treatments. Pulse treatments with 10% sucrose for 4–24h were relatively ineffective at reducing floret and bud abscission but longer pulses of 48h reduced abscission. The relative ineffectiveness of sucrose pulse treatments appeared to be due to the low water uptake of the stems (1–3ml/day). Reducing the number of florets and buds on an inflorescence reduced abscission of florets and buds, and increasing stem length from 25 cm to 50 cm decreased bud abscission. This reduction in abscission is possibly due to the increased availability of assimilates for the remaining buds and florets or reduced competition for assimilates. Exogenous ethylene treatments (9µl/L for up to 24h) had no effect on abscission, although STS treatment (4mM, 4h) significantly reduced floret abscission when stems were held in vase solutions of sucrose. We conclude that postharvest floret abscission in A. praecox is influenced primarily by the availability of assimilates to the developing florets.

South Africa has a large number of indigenous geophytes and many of these have been developed as cut flower crops. Sandersonia aurantiaca Hook. is one of the geophytes to be developed in the latter half of the 20th century. Most of the development work leading "domestication" of sandersonia occurred in New Zealand, led by pioneer growers working closely with researchers. Test marketing of the cut stems in Japan quickly demonstrated the commercial potential of the crop that derived its popularity from its distinctively shaped, golden orange lantern-shaped flowers.Today we have a good understanding of the physiology of the plant and protocols have been developed for production of high quality tubers and flowers, and for all year round production. Sandersonia has been used as a model crop for studying senescence of anethylene-insensitive flower, and postharvest handling protocols have been developed for the cut stems. Sandersonia is a monotypic species with limited genetic variation and further expansion of the crop and related species will occur with the introduction of new characteristics. New characters are being introduced through hybridisation with related genera. (C) 2008 Elsevier B.V. All rights reserved.

The effects of two growing environments (a glasshouse and a sheltered outdoor site) and four planting dates (11 October and 22 November 2000, 3 January and 14 February 2001) on the cut flower production of Santonia ‘Golden Lights’ were assessed. Stem length, stem strength, flower colour and tuber weight were affected by growing environment and planting date. Stem length on outdoor grown plants was reduced by 280 mm, stem strength was improved and there was some reddening of flowers, but the number of flowers/stem was not affected. Results suggest that when Santonia is grown under suitable environmental conditions, stems that are acceptable as cut flowers can be produced. INTRODUCTION Sandersonia aurantiaca (Hook.) has been developed over the last 20 years by growers and researchers in New Zealand as a successful cut flower crop with export receipts of NZ$2.6M in 2002 (HortResearch, 2002). Countries such as Japan and South Africa are now producing Sandersonia so new cultivars are needed if New Zealand is to maintain its market share. The new hybrid Santonia ‘Golden Lights’ was released in 1998 by Sanza Ltd in New Zealand. It is a Sandersonia aurantiaca x Littonia modesta F1 hybrid (Morgan et al., 2001). With its ability to rapidly produce large tubers that produce long stems with a number of laterals and leaves with small tendrils, Santonia ‘Golden Lights’ was initially envisaged for the nursery market as a climber. Preliminary studies have indicated that in cooler conditions it may be possible to produce stems with the length, strength, flower colour and vase life to make Santonia suitable as a cut flower (Morgan et al., 2003; Eason et al., 2001). Studies on Sandersonia have shown that the time of planting and growing environment affect stem length and tuber production (Clark, 1994, 1995; Clark and Burge, 1997; Clark and Reyngoud, 1997). The objective of this study was to examine the effects of planting date and environment on Santonia ‘Golden Lights’ to determine whether production systems could be developed to produce cut flower stems of export quality. MATERIALS AND METHODS The effects of two growing environments (a glasshouse and an outdoor site sheltered with wind break cloth) and four planting dates at six-week intervals (11 October and 22 November 2000, 3 January and 14 February 2001) on cut flower production were assessed in a randomised block design with four replicates. Both growing sites were at the Pukekohe Research Centre, Pukekohe, New Zealand. At the first planting date a line of 10-15 g Santonia tubers that had been stored at 5°C for 4-5 months was assigned at random to one of four planting dates. The three groups assigned to later planting dates were transferred into three polystyrene boxes (100/box) where they were placed between layers of newspaper then returned to storage at 3°C (Morgan et al., 2003). Proc. IX Intl. Symp. on Flower Bulbs Eds.: H. Okubo, W.B. Miller and G.A. Chastagner Acta Hort. 673, ISHS 2005 266 On each planting date, a box was placed into a thermostatically controlled incubator at 20°C for 7 days to pre-sprout the tubers (Clark, 1994). The tubers were then divided and graded to give an even line of single growing point tubers for each replicate. Owing to losses in storage and non-viable growing points, the tuber numbers/replicate for plantings 1-4 were 22, 19, 19 and 12 respectively, with mean planted tuber weights of 6.1, 6.0, 5.5 and 6.0 g. Tubers were dipped in a fungicide mixture containing 0.5 g/litre benomyl and 2.0 g/litre thiram for 10 min prior to planting into polystyrene trays (595 x 420 x 190 mm) containing 25 litres of commercial (Yates NZ Ltd) nitrogen stabilised composted radiata pine bark fines (0-8 mm) with incorporated fertilisers. At planting, the water soluble nutrient content of the bark medium was measured in a 1:1.5 media:water (v:v) extract using colorimetry and atomic absorption methods. Media nutrient levels were pH 5.3, Ca 68 ppm, K 63 ppm, P 19 ppm, Mg 43 ppm and N 70 ppm. All trays were mulched with 10 mm of sawdust. The crop was supported with netting and watered daily at a rate of 2.5 litres/m. The glasshouse was unheated and vented at 25°C. Air temperatures were measured at 500 mm above soil level, soil temperatures at a depth of 75 mm, and both were logged at 1 min intervals using a Campbell CR10 data logger. Daily solar radiation (MJ/m) was recorded by a National Institute of Weather and Atmospheric Research automatic weather station sited 100 m away from both growing environments. The stems were harvested just above the second leaf when the second flower had reached anthesis. Harvest date, stem length and weight, the number of laterals, flower number/stem and per lateral, flower size (length and width), stem strength and flower colour (Table 1) were measured. For all treatments, watering was stopped 18 weeks after planting, and tubers were lifted and weighed 2 weeks later. Data were analysed using analysis of variance (GENSTAT 2002). RESULTS AND DISCUSSION The time to flower harvest was significantly (P=0.002) affected by both planting date and environment (Table 2). It was, on average, 13 days longer for the tubers planted outdoors than for those in the glasshouse. This period gradually decreased over the first three planting dates before increasing for the fourth. This pattern matched changes in mean temperature during the season (Table 9). Similar seasonal patterns of flower harvest times have been found in Sandersonia (Clark, 1994, 1995; Clark and Reyngoud, 1997). Davies et al. (2002a) found a strong correlation between temperature and the time to flower harvest in Sandersonia in controlled environment studies. There was a significant interaction between planting date and growing environment (P=0.001) on stem length. Stems were on average 280 mm longer in the glasshouse than outdoors. Stems were longest for planting times 1 and 2 in the glasshouse and shortest for the outdoor planting at time 2 (Table 3). Internode and stem length in many ornamental plants increase with increasing DIF (day/night temperature differential) (Moe and Heins, 1990). Although Sandersonia stems were shorter in greenhouses in the hot summer months, they were still longer than stems produced by plants grown outdoors (Clark, 1994; Clark and Reyngoud, 1997). Controlled environment studies with Sandersonia have found that stem length increases at temperatures up to 24°C, at low light intensities and at higher DIF (Davies et al., 2002a, b). Stem length of Santonia is probably influenced by an interaction of these three factors. It was cooler outdoors than in the glasshouse (Table 9). Outdoor DIF values (Table 9) would have been less than glasshouse values as daily maximum glasshouse temperatures are on average 3-5°C greater than ambient in the best ventilated greenhouses and drop to ambient outdoor temperatures at night. Light intensities were 22% higher outdoors in January than in the glasshouse (measured using a Licor quantum sensor). These factors would reduce stem length outdoors compared to the glasshouse, and combine to produce the longest stems in the glasshouse and the shortest stems outdoors from planting date 2. This would suggest that a DIF value of 8.0-9.0°C is optimal for Santonia production.

Bacterial soft rot, caused by Erwinia carotovora subsp. carotovora, is the most important disease affecting callas grown in New Zealand. The aim of this experiment was to determine the effects of chemical drench treatments on the incidence and severity of soft rot in callas grown in soil and in sawdust. There were four drench treatments: (1) no drench; (2) one drench application immediately after planting; (3) drench applied after planting, then at 28-day intervals; (4) drench after planting, then at 28-day intervals from the first visible occurrence of soft rot plot. The soil drench was an aqueous solution of 0.05% Kocide ® (350 g/kg copper), 0.05% Terrazole ® (350 g/kg etridiazole), and 0.15% Terrachlor ® (750 g/kg quintozene). Five litres of drench solution per plot was applied to the soil around the base of each plant. More calla plants died when grown in soil than in sawdust for each drench treatment. For both growing media, drenching plants at 28-day intervals resulted in the lowest numbers of dead plants during crop growth and rots in lifted tubers.

The effects of combinations of duration of bulb storage, storage temperature, and leaf and root pruning regimes before storage on flower production in Cyrtanthus elatus were studied in three experiments. In the first experiment, bulb viability was 93% after 49 days and declined at 98 and 147 days of storage at 1 degrees C to 3%. Storage at 5 degrees C for 147 days did not affect viability but flowering date was delayed 24 days. In subsequent experiments storage at 5 degrees C did not delay flowering after 50 days, but after 100 days flowering was up to 23 days earlier and produced stems 17-22% shorter. Increasing severity of leaf and root pruning reduced the number of flower stems/bulb 46-60%, but did not affect stein length. With storage at 5 degrees C it may be possible to spread the flowering season.

Hypericum is developing as a significant export cut foliage crop in New Zealand, but of concern to growers has been a leaf purpling disorder. The effects of berry removal, four soil potassium (K) levels (0.42, 1.33, 1.89, and 2.59 meq/100 g), and 10 soil K/Mg ratios (from 0.26 to 1.78) on the leaf purpling disorder in hypericum were studied in three experiments. Leaves from a growers property with the disorder had hi-her K and lower magnesium (Mg) concentrations than leaves without the symptoms. There was no effect of berry removal or retention on the incidence or severity of the disorder. Increasing soil K levels increased leaf purpling scores. The leaves had significantly higher concentrations of K and lower levels of Mg. There is a strong relationship between leaf purpling and the soil K/Mg ratio, and this disorder can be reduced to acceptable levels at ratios less than 0.30.

The effects of two soilless media (peat/ pumice and bark), three nitrogen (N) rates (25, 100, and 500 g N/m(2)), three potassium (K) rates (12.5, 50, and 200 g K/m(2)), and media pH (4.4, 4.8, 5.5, and 5.9) on tuber russeting in Sandersonia aurantiaca were assessed in two experiments. Russeting scores were less in the bark medium and increased with N rate and with increasing pH. Tuber weight and secondary tuber numbers were less in the bark medium than in the peat/pumice medium and increased with increasing N rate and pH, but declined at the highest rates. Tuber numbers were greater in the peat/ pumice medium and with increasing N rate. Tuber N concentrations increased markedly with increasing N rate. There was no effect of K rate on tuber quality. To maximise production of export quality tubers with low secondary tuber numbers and an acceptable level of russeting, N rates of up to 33 g N/m2 in a peat/pumice medium are recommended at pH levels of less than 5.0. Using a bark medium will reduce tuber russeting, secondary tuber numbers, and weight.

In the current study two Cyrtanthus cultivars (one red flowered and one orange flowered) were grown at three locations in New Zealand. Flowering stems were harvested when the florets were in tight bud, pulsed for 24 h at 5-7degreesC with commercially available postharvest solutions or water, then packaged and stored to simulate transport before assessment of postharvest performance. In two experiments the vase life of the orange flowered cultivar was 15 and 18 days in water, whereas in other experiments the maximum vase life of the red flowered cultivar in water was 11 days. The majority (>90%) of the florets on the orange cultivar were fully open before the initiation of floret senescence on the same stem, whereas 40% of the florets of the red cultivar were starting to senesce when only 80% of the florets on the stem were open. In addition, bud abortion was more prevalent for the red flowered cultivar, which had an average rate of 9.2% bud abortion for stems treated with water compared to 0.1% for the orange flowered cultivar. Chrysal-SVB was the only effective solution tested for extending the vase life of these cultivars, giving an extension of 2 days for both the orange and red Cyrtanthus flowers. Treatment of less mature stems of the orange flowered cultivar with a double rate of Chrysal-SVB increased the vase life by 4 days. Stems were held in water after harvest and cool stored for up to 72 h before packing without affecting the subsequent vase life. In addition, we have shown that the orange flowered cultivar can be held dry in a cool store for up to 4 days after packaging with a subsequent vase life of 15 days in water.

The size of apical growing points on four grades of sandersonia tuber (3–5, 5–7, 7–10 and >10g) increased with increasing tuber weight (R2=0.71). These tubers were divided in two separate experiments to provide weights of 16.7, 33 and 50% and 50, 75 and 100% of the original grade size weights. Tubers were grown in the main season under standard forcing conditions. Harvested stem length was significantly greater with increasing tuber size, but declined with increasing severity of cutting treatment. Similar results also occurred with stem weight, flower number and vase-life. Regression analysis of stem length versus planted tuber size for the combined data from both experiments produced a significant relationship (R2=0.83), with the fitted line being: L=673.5−336.9×0.7626T (where L is the stem length, T the tuber planted weight and 673.5 is the upper asymptote). Stem size and flower number were influenced by tuber weight rather than by apical growing point size.

The effects of three tuber planting dates (I September, 1 November and 1 January) and three planting densities (192, 256 and 320 tubers/m(2)) on tuber production in Sandersonia aurantiaca were assessed. Tubers were grown in a commercial peat:pumice media in polystyrene trays located in an unheated glasshouse and using standard growing methods. Tuber numbers, weights (by grade size - 1-3, 3-5, 5-7, 7-10 and 10+ g) and numbers with secondary tubers were measured. Tuber numbers, weights and the number of secondary tubers decreased with planting date and with increasing planting density. Tubers were mainly in the 10+ g weight grade in the first planting, but were more evenly distributed across all grade sizes in the two later plantings. These results show that planting density can be manipulated along with planting time to maximize tuber numbers in the larger grade sizes and reduce secondary tuber numbers.

The effects of five tuber lifting dates (16, 18, 20, 22, and 24 weeks after planting), with and without curing (20degreesC for 7 days), and of three storage temperatures (4, 6, and 8.5degreesC) for three storage durations (90, 120, and 150 days) on subsequent tuber sprouting and stem quality of Sandersonia aurantiaca (Hook.) were investigated in two experiments. Tuber weight increased up to 18 weeks after planting. Tuber moisture loss in storage was greater for tubers lifted 16 weeks after planting (20.9%) than for tubers lifted subsequently (6.5-10.1%). Stem weight, stem length, and flower number per stem were lowest in the tubers lifted earliest (after 16 weeks). Week 18 from planting (sterns showing leaf yellowing/senescence) is probably the earliest time tubers should be lifted. There were no benefits from curing the tubers. Percent tuber sprouting decreased slightly with increasing storage duration. Tuber sprouting time decreased with increasing storage duration, and at the longer storage duration with increasing storage temperatures. Stem length and weight increased with storage duration. Stem length was greater following storage at higher temperatures. Results indicate that temperatures around 8.5degreesC in combination with short-term storage periods of 90-150 days could improve the production of tubers stored until mid August.

Abstract The effects of six target media pH levels (4.5,5.0,5.5,6.0,6.5) on cut‐flower (glasshouse) and tuber production (outdoor) in Sandersonia aurantiaca (Hook.) were compared in two experiments. The effects of these pH levels on tuber storage and subsequent cut‐flower production were assessed in a third experiment in a glasshouse. Actual media pH levels achieved varied from 4.1 to 6.1 in the glasshouse and from 4.4 to 6.5 outdoors. The pH levels in the glasshouse produced small differences in stem length but no significant differences in stem weight, flower number, or vase life. At the highest pH level, the number of stems harvested was less and the number of rejected flowers greater than at lower pH levels because of decreased stem length or physiological disorders, such as leaf chlorosis and leaf tip browning on the lower leaves. Leaf concentrations of S, Mn, and Zn declined with increasing pH level whereas Mg increased in the cut‐flower experiment. The number of tubers lifted outdoors was least at the highest pH level but there was no difference in mean tuber weight. Tuber nutrient concentrations of N, Ca, Mn, Zn, and Cu declined with increasing pH level whereas Mg increased. There were no production differences at forcing with the lifted tubers. For sandersonia cut‐flower production a media pH range of 4.4–5.3 appears to be suitable, whereas for tuber production pH levels of 4.4–6.1 were best. As sandersonia production usually involves both growth phases, a range pH of 4.4–5.3 would be suitable with a target pH of 5.0–5.3 recommended for growth in peat‐pumice media. This will ensure mid‐range tuber and leaf nutrient concentrations and optimised production.

The effects of bulb grade sizes (24-30, 31-37, 38-44 and greater than or equal to45 mm) and light intensity (+/-40% shade) on the cut flower production of Crytanthus elatus bulbs were assessed over two seasons. In a second experiment the effects of bulb storage treatments (0, 72 and 132 days storage at 4 and 10degreesC) and growing environment (a glasshouse or sheltered outdoor site) were assessed. Stem length and weight, flower numbers/stem and stem numbers/bulb increased with bulb size. Shade delayed flowering by 14.6 days and decreased the number of stems/bulb in the first season. In the second season shade further decreased the number of stems/bulb. In the second experiment storage delayed flowering in the greenhouse in the first season by up to 75 days. Stems were longer in the glasshouse compared to outdoors, but stem numbers/bulb were similar. In the second season stem numbers/bulb were fewer from the longer storage duration bulbs. There were no significant differences in flower production or flowering time between the two bulb storage temperatures.

The effects of three planting media (50:50 peat:pumice, Pinus radiata bark, and soil) at two nutrient rates (1.0 and 4.0 kg/m(3) Nutricote) were assessed on sandersonia (Sandersonia aurantiaca (Hook.)) tuber production, the incidence of tuber russeting, and subsequent performance of tubers. Tuber weights were greater at the higher nutrient rate. Lighter tubers were produced in the bark medium than in the peat:pumice or soil. Tuber russeting was less, and commercially acceptable, at the low nutrient rate in all media. At the high nutrient rate russeting was greater in tubers grown in peat:pumice and soil compared to those grown in bark. At the high nutrient rate tissue concentrations of K, N, S, and P were greater. Tubers grown in bark had lower concentrations of N and S compared to tubers grown in soil and peat. At the high rate of nutrition tuber sprouting in the subsequent season was less in the tubers grown in soil and peat:pumice compared to the bark-grown tubers. Stem length, stem weight, flower number, and vase life from tubers produced in bark at the high nutrient rate were similar to those produced in the soil and peat:pumice media at the low nutrient rate. There was no improvement in production indices for the tubers grown in soil or peat:pumice at the high nutrient rate. These findings show that if grown in peat:pumice or soil, sandersonia tubers should be produced at low nutrient levels to reduce the incidence of tuber russeting and to improve subsequent forcing. If grown in bark media, higher nutrient rates can be used to maintain forcing quality without causing high levels of russeting.

The effects of five nitrogen (N) application rates-14.2, 28.4, 56.8, 113.6, and 227.2 g N/m(2) (equivalent to 37.5, 75, 150, 300, and 600 ppm of N as a daily liquid feed), on greenhouse cut flower production and outdoor tuber production in Sandersonia aurantiaca (Hook.) were compared in two experiments using a peat pumice medium. Stem length and weight declined with increasing N rate. Tuber weight declined slightly along with tuber quality with increasing N rate. High N rates resulted in an increased incidence of tuber disorders including secondary tuber formation and tuber rots. Leaf N concentration increased with N rate to a maximum of 56.8 g N/m(2), but tuber N continued to increase (from 0.68 to 2.01% dry weight) with increasing N rate. The effects of the N rates on tuber storage and subsequent cut flower production were assessed at two N rates (28.4 and 113.6 g N/m(2)) in a third experiment. Leaf nutrient concentrations were not affected when tubers were forced at the two N rates in the third experiment nor was vase-life of stems. This study indicates that sandersonia requires low-medium amounts of nitrogen and that an N rate of c. 28.4 g/m(2) would optimise both tuber quality and stem production for sandersonia grown in a soil-less medium. Tuber and leaf nutrient concentrations at this N rate could be used for crop cultural guidelines for both flower and tuber production.

The effects of four nitrogen (N) application rates (5, 10, 20, 40 g N/m(2)) and four potassium (K) soil levels (0.4, 0.8, 1.8, 3.2 me/100 g) on soil-grown Sandersonia aurantiaca (Hook.) stem and tuber production were evaluated. Leaf concentrations of N and K declined with plant age but were greater at the higher N and K levels, respectively. Small increases in some stem production indices (flower number, percentage side laterals) occurred with increasing N but declined with increasing K (stem length). Tuber weights declined with increasing levels of N and K with the largest tubers, 7.9 g produced at 10 g/m(2) N and 1.8 me/100 g K. This study indicates that moderate N and K nutrition rates should be used for soil-grown sandersonia to optimise both stem production and tuber weights.