The Bedding and Pot Plant Centre New product

The Bedding and Pot Plant Centre New product opportunities for bedding and pot plant growers AHDB Horticulture funded project PO 019 a Dr Jill England Chloe Whiteside www. adas. uk

Overview • Baginton Nurseries • Summary of Year 3 (2017/18) • Year 4 trials (2018) • Further information

Baginton Nurseries • Established in 1981 • 5 minutes drive from Stoneleigh Park • Wholesale nursery producing bedding and pot plants, hanging baskets and planted containers • 6 -acre site • Supply: local authorities, landscapers, pubs, restaurants and • 3 acres of protected structures commercial premises • 4000 m 2 outside beds

Year 3 (2017/18) – summary 1. 2. 3. 4. 5. 6. 7. Improving cutting success Verbena leaf spot and chlorosis Evaluation of PGRs on bedding and pot plants Evaluation of PGRs on Poinsettia Pre-Christmas production of Hellebore White Hellebore performance in shelf life Overwintered perennials

1. Improving cutting success To investigate the use of a range of products to increase the success rate and decrease rooting time when striking un-rooted cuttings Products Omex SW 7 (0. 5 L/ha) Signum (1. 35 L/ha) Rhizopon AA (6 tablets/L) Serenade ASO (10 L/ha) Water Treatments Spray Quick dip (5 secs) Long dip (30 min submersion) Water only (control) Pelargonium ‘Bianca’ (Copyright Dümmen)

1. Improving cutting success • • Pelargonium Green Leaf Series ‘Bianca’ Three days in transit, then cool storage Set up: • Batch 1 - 03 March 2017 • Batch 2 - 06 March 2017 72 -cell plug tray (half), 15 cuttings / tray 29 treatments, products applied alone and combinations Growing medium: Peat + 20% perlite propagation medium, p. H 5. 8 – 6. 2 Heated glasshouse, heated bench White propagation film cover

1. Conclusions • Rooting significantly improved compared with untreated and QD controls: • Rhizopon AA (QD) • Rhizopon AA + Signum (QD) • Rhizopon + Serenade ASO (QD) • Rhizopon + Omex SW 7 + Signum (QD) • Quick dip treatments more effective than long dips and sprays • Quick dip in water alone will improve rooting • Omex SW 7 + Signum (LD) – all cuttings failed by 7 DAT

2. Verbena chlorosis & leaf spot To investigate plant nutrition, water quality and environment as possible causes of necrotic spotting and associated symptoms in Verbena Woodlands Nursery Quartz Blue (seed) Transplant week 19 Standard 6 -pack p. H: 4. 5 and 6. 5 Environment: ambient and humid Water quality: borehole, rainwater, 50: 50 blend • Watering: standard and wet • •

T 1. Wet, borehole, humid, low p. H (4. 5) T 3. Wet, borehole, ambient, low p. H (4. 5) T 11. Wet, 50/50 blend, ambient, low p. H (4. 5 )

2. Summary • Fewer symptoms in humid than ambient treatments. Exception: dry borehole, low p. H treatment and dry, 50: 50 blend (both p. Hs). Smaller differences between dry treatments. • Symptoms more severe in wet treatments than dry. • Plants generally stretched in humid treatments compared with ambient; taller in wet than dry. • Root quality poorer in humid, wet treatments. • Plant quality: none marketable.

3. Evaluation of PGRs on bedding and pot plants - 2017 To evaluate a range of PGRs either approved in the UK or in other European Countries for use on bedding and pot plants Zantedeschia • Zantedeschia potted wk 18 at Lovania, delivered to Bagintons wk 20 • 12 varieties • 1 L pots • Sprays applied 30 May & 09 June • Drenches applied 17 May, 30 May and 09 June Bedding • Bedding transplanted wk 21 • Begonia Semperflorens Heaven Mixed, Dianthus Festival Mixed, Geranium Horizon Mixed and Pansy Matrix Mixed • Standard 6 -packs • Sprays and drenches applied 30 May & 09 June

3. Evaluation of PGRs on bedding and pot plants - 2017 New Guinea Impatiens • • Potted wk 22 Divine Cherry Red 1 L pots Sprays and drenches applied 09 June and 19 June

3. Treatment list Product Active ingredient Dose rate Approval status Untreated N/A N/A Dazide enhance daminozide 6 g/L Full approval – spray only Medax Top mepiquat chloride + 2. 25 ml/L prohexadione-calcium Moddus – 1 app only trinexapac-ethyl Primo Maxx II trinexapac-ethyl Regalis Plus – 1 app only prohexadione Terpal + Activator 90 (non-ionic wetter) ethephon + mepiquat 2 L/ha + 0. 4 ml/L chloride Not approved EAMU 3062/10 – spray only. 1 application only permitted per crop. Not approved. Based on Cutaway EAMU 2 L/ha 2140/16 EAMU 0181/15. 3 weeks between 1. 25 kg/ha applications. 0. 6 L/ha • Applied in 300 L/ha water. • Experimental permits used where necessary. • All treatments applied as sprays and drenches. Not approved

3. Bedding phytotoxicity week 25 Dianthus Unt. vs Terpal + Act. 90 - drench Unt. vs Regalis Plus - drench Unt. vs Medax Top - drench

3. Bedding phytotoxicity week 25 Geranium Unt. vs Terpal + Act. 90 - drench Unt. vs Regalis Plus - drench Unt. vs Medax Top - drench

3. Bedding phytotoxicity week 25 Pansy Unt. vs Terpal + Act. 90 - drench Unt. vs Moddus - drench Unt. vs Primo Maxx II - drench

3. Pot plant phytotoxicity week 29 New Guinea Impatiens Unt. vs Terpal + Act. 90 - drench Unt. vs Primo Maxx II - drench Unt. vs Regalis Plus - drench • No phyto seen in the Zantedeschia

3. Summary - 2017 • Bedding: drenches generally more phytotoxic than sprays. • Begonia and Geranium appear to be more sensitive than Dianthus and Pansy. • Terpal + Activator 90 drench too strong, causing some plant death, particularly in the Geraniums. • Impatiens: Drench treatments were all too strong and with varying degrees of phytotoxicity. • No phytotoxicity recorded in the Zantedeschia. • Zantedeschia varieties most responsive to Terpal + Activator 90 drench.

Evaluation of PGRs on bedding and pot plants – 2018 Aim: To evaluate a range of PGRs for use on bedding and pot plants (efficacy and phytotoxicity) • Refine 2017 treatments • Medax Top, Terpal, Regalis Plus, Primo Maxx II, Pirouette • Dianthus Festival, Geranium Horizon, Osteospermum ‘ Akila’ and Pansy Matrix • Standard 6 -packs (bedding) and Jumbo 6 -packs (Osteospermum ) • Sprays and drenches

4. Evaluation of PGRs and fungicides on Poinsettia - 2017 To evaluate a range of PGRs and fungicides either approved in the UK or in other European Countries for use on Poinsettia • Infinity (Dummen), 13 cm pots • Potted: week 31, pinched: week 33 • Treatments: from week 39 • Two trials: • Main trial: 5 applications, full and half rate (fully replicated trial) • Observational trial: 1 application at double rate (unreplicated) Non-approved uses applied under experimental permit

4. Products and treatments Product Active ingredient Dose rate Approval status Medax Top mepiquat chloride + 2. 25 kg/ha prohexadione-calcium Regalis Plus prohexadione 1. 25 kg/ha Primo Maxx II trinexapac-ethyl 2. 0 L/ha Terpal + Activator 90 ethephon + mepiquat 2. 0 L/ha 40 ml/100 L chloride Stabilan 750* (reference) chlormequat 1. 0 L/ha EAMU 0910/17. Bumper 250 EC propiconazole 0. 4 L/ha EAMU 0707/09. Systhane 20 EW* myclobutanil (reference) 0. 3 L/ha Not currently approved. Previous label rate used. Untreated N/A *Main trial only water only Not approved EAMU 0181/15. 3 weeks between applications. Not approved. Based on Cutaway EAMU 2140/16 Not approved • Applied in 300 L/ha water.

4. Conclusions PGRs • Terpal + Activator 90: most promising; potential at lower rates. • Regalis Plus, Medax Top & Primo Maxx II: severe phyto cumulated after multiple applications; may be potential for early application. Fungicides • Bumper and Systhane 20 EW: good crop safety other than reduced height.

Evaluation of PGRs and fungicides on Poinsettia - 2018 • Variety: Infinity • Height specification: 22 -28 cm • Stabilan 750 (reference) • Terpal +/- Activator 90 (2 -3 lower rates) • Regalis Plus (1 & 2 early applications, Stabilan 750) • Bonzi (2 -3 rates) • Elasto (polyglycerol based wetter) + reduced rate Regalis Plus, Terpal, Stabilan 750 • No further work with Medax Top or Primo Maxx II

5. Pre-Christmas production of Hellebore To advance the season for pot grown coloured varieties of Hellebore to include marketing prior to the New Year Cultivation Varieties • Anne’s Red • Potted week 16 • Established in a tunnel, then grown • HGC Madame Lemonnier outdoors from week 21 with shade netting overhead • HGC Paradenia • Plants transferred to ADAS • Molly’s White Boxworth in week 32 • Penny’s Pink Cool treatments • Royal Emma 2°C for six weeks from: Madame 1. Mid-August, week 33 2017 Lemonnier (Copyright Heuger) 2. Mid-September, week 37 2017

5. Cool treatments Potting in week 16 Plant growth Flowering time Cool treatments at 2°C

5. Conclusion • CS 1 and CS 2 - Flowers on all varieties by 19 December. • More flowers in CS 1 than CS 2. • Royal Emma performed well in both treatments with most flowers and buds. • Molly’s White slower to flower. • No flowers in outdoor control. • Quality issues – plants slightly leggy, pale flower colour. Penny’s Pink (l-r: outdoor control, CS 1, CS 2)

6. Hellebore: shelf life performance of white varieties To evaluate the shelf life performance of micro-propagated Hellebores produced as pot plants for pre-Christmas marketing Cultivation • • • Potted week 16, 1. 5 L pots Varieties • Established in a tunnel, then • grown outdoors from week 21 • with shade netting overhead • Plants transferred to ADAS • Boxworth in week 44 Shelf life completed week 47 – week 1 Second shelf life currently underway H. Niger St. Antonia H. Niger St. Lucia HGC Jesko HGC Wintergold Royal Emma

7. Overwintered perennials – 2016 -17 To investigate the low input production of herbaceous perennials for early spring marketing (week 14) • Sown: weeks 27 & 29 • Transplanted week 40 • 1 L & Jumbo 6–pack) • Growing conditions: • Pre-germination – heated glass • Post-germination – unheated glass / polythene • Post-transplant – unheated glass / polythene (min. heat) • Nutrition: - CRF: 1. 5 kg /m 3, 6 month + liquid feed Trial set up under glass (above) and polythene (below)

7. Conclusions – 2016 -17 By the end of March 2017: • Campanula persicifolia ‘Takion Blue’, C. glomerata ‘Acaulis’, Scabiosa japonica var. alpina ‘Ritz Blue’, Prunella grandiflora ‘Freelander Blue’ and Silene alpestris ‘Starry Dreams’ had flower buds present • Scabiosa japonica var. alpina ‘Ritz Blue’ and Silene alpestris ‘Starry Dreams’ produced fully open flowers Scabiosa japonica var. alpina 'Ritz Blue' Silene alpestris 'Starry Dreams' • Verbena rigida and Gaura lindheimeri ‘Sparkle White’ particularly suffered cold damage • Two weeks heat at 15˚C insufficient to advance species tested to full flowering Prunella grandiflora 'Freelander Blue'

Overwintered perennials – 2017 -18 To investigate the low input production of herbaceous perennials for early spring marketing (week 14 & 16) • Sown: week 29 • Transplanted week 40, 1 L & Jumbo 6–pack) • Pre-treatment conditions (Bagintons): • Pre-transplant – heated glass • Post-transplant – 2 weeks heated glass • Frost-protected polytunnel to week 50 • Treatments (W D Smith): • 3 batches – 12˚C, vent 15˚C; control batch • Heat applied from mid Jan, Feb & March • With / without PGR • Growing media: Bulrush; Osmocote Exact High K, 5 -6 m @ 2. 5 g/L

Year 4 (2018) 1. Overwintered perennials 2. PGRs on bedding & pot plants 3. PGRs on Poinsettia 4. PGRs on plugs

Evaluation of PGRs over plugs prior to potting To evaluate a range of PGRs for use on bedding plant plugs (drench application) prior to transplant • Medax Top, Terpal, Regalis Plus, Primo Maxx II, Pirouette • Dianthus Festival, Geranium Horizon, Osteospermum ‘ Akila’ and Pansy Matrix • Single drench application two days prior to transplant • Transplant into standard 6 -packs (bedding) and Jumbo 6 packs (Osteospermum )

Ideas for future work? • Contact: • Jill. England@adas. co. uk • Chloe. Whiteside@adas. co. uk • David. Talbot@adas. co. uk

Further information Twitter: @ahdbbppc Report: March 2018 AHDB Horticulture News articles Open days/Events: • AHDB Ornamentals Conference – 20 Feb 2018 • Ball Colegrave Technical Day – 22 Feb 2018 • Summer Open Evening – 19 June 2018 Video: Spring 2018 Study tours: • North-West Study Tour TBC

The Management Group • Caroline Shove (Chair) (Bryants Nurseries) • • Will Lamb (Baginton Nurseries) Jack Olds (Baginton Nurseries) Mike Smith (W D Smith & Son) Ewan Macmillan (Burston Nurseries) Nigel Johnson (Lovania Nurseries) James Lisher (Cobbins Nurseries) Ollie Opperman (Oppermans) Neil Bragg (Bulrush Horticulture) • • Georgina Key (AHDB Horticulture) Wayne Brough (AHDB Horticulture) Harry Kitchener (Consultant) Chris Need (Consultant) Jill England (ADAS) Chloe Whiteside (ADAS) David Talbot (ADAS) Tim O’Neill (ADAS)

Acknowledgements • Will Lamb and Jack Olds, Baginton Nurseries • Woodlands Nursery • Newey Roundstone • Ball Horticulture • BASF • Bulrush Horticulture • Fargro • • • Heuger ICL Kapiteyn Bulbs Lovania Nurseries Omex Horticulture Pöppleman