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Minipot development at Levin Horticulture Recearch Centre 1984

This article by Janice Swanwick with accompanying photos is described as "not published - 1984".

Mini pot plants developed by Horticulture Research Levin 2

Scientist working at Horticulture Research Levin 1984

Scientist working at Horticulture Research Levin 1984 4

Researchers at a major horticultural centre in New Zealand have come up with a product that could beat the Japanese at theeir centuries-old tradition of bonsai.

They are dwarfing pot plants - producing 'bonsai' versions of several dozen varieties ranging from leptospermum and coleus through to anthuriums and chlorophytums.

Interest in the export potential of the project has been widespread, particularly from Japan.

The minipots, as they are officially called, are miniature versions of their normal-sized reaations in every respect, except for the flowers.

"You can dwarf the plant- it doesn't even affect the foliage colour - but not the flower", says Steve Butcher, the scientist in charge of the minipot project, at the Levin Horticulture Research Centre.

Anything with a big flower such as antheriums, kowhais (a New Zealand native) or alocasias won't flower because the tiny plant can't produce a flower big enough.

"if we want flowering plants, we look for something with small flowers which are going to be in proportion e.g. leptospermum or single geraniums."

The Lilliputs of the pot plant world are aimed at situations where there is not enough space for a full plant display, for instance a hospital ward, small flats or units, and dining settings.

Contacts in Singapore and Malaysia have expressed interest in using the minipots as dining table centrepieces in international hotels, and coffee shops.

A Japanese senior research fellow in floriculture who spent a year at th Levin centre felt the leptospermum had particular potential in his home country. Samples have since been sent to Japan.

The project team - Steve and technician Alice Wood - also are looking at dwarfing Japanese pot plant varieties for the United States market.

Trial shipments of the minipots are planned to test the US reaction.

The idea of miniature pot plants were first mooted at the centre five or six years ago, but in-depth research has been going for less than three years.

"As far as I know no-one else is doing it the same way," Steve said.

"There are small pot plants being produced in many places but they are not maintained as miniature pot plants."

Studies by the New Zealand Market Research Unit and trial marketing have demonstrated a large potential market for pot plants, especially new or novel varieties or ideas.

The unit has found that the Japanese spent about $NZ100 million on pot plants in 1980, and this is expected to increase to about $NZ800 million in 1990.

In Australia, an ESAMS report has estimated that the pot plant market in Europe and the US was worth more than $AUD 1300 million per annum in 1981.

Steve estimates that it takes six to eight months to get a saleable product.

However, the team still wants to investigate further transport problems. Studies are also continuing into basic flower physiology and the control of flowering.

A reduction in labour requirements by using such techniques as direct sticking of cuttings also needs to be investigated.

A major problem for export is stringent quarantine regulations.

Japan requires that 50 per cent of all potted plants be removed from their containers for root inspection. This is despite the fact that a sterile bark media was accepted for growing.

One way around this is to ship bare-root plants for potting and growing-on in Japan; another is the use of sterile foam media. Both these methods are to be investigated.

The centre's outline to growing minipots relates specifically to leptospermum "as the most promising species tried. However, the general principles can be applied to any species.

Of more than 50 species tried at Levin, about one third have been what the centre describes as reasonably successful.

These include Leptospermum scoparium, Fuchia procumbens, Anthurium andreanum, Vriesia splendens, Davallia canariensis, Asplenium bulbiferum, Blechnum penna-marina, Earina mucronata, Earina autumnalis, Pinus radiata, Dendrobium kingianum, Hedera variegat, Sungonium sp., Senecio greyii, Dendrobium kingianum Alba, Fittonia argyroneura and Peperomia argyroneura.

Others tried have been Anthurium scherzerianum, Fuchsia perscandens, Adiantum cuneatum, Podocarpus dacrydiodes, Rhopalostylus sapida, Dendrobium cunninghamii, Mazus radicans, Eunomymus sp., Selaginella sp., Carex sp., Pimelia sp., Lavendula officinalis, Clianthus puniceus, Hebe sp., Gentian sp., Epilobium pictum, Cotula sp., Pratia sp., Nertera sp., Cyclamen sp., Corokia contoneaster, Ceropegia bulbosa, Viola cunninghamii, Metrosideros axcelsa, Libartie ixiodes, Kowhai Sophora microphylla, Pelargonium sp., Alocasia cuprea, and Sophronitis coccinea.

A dozen varieties have been used in the Leptospermum trials. Half were dwarf varieties - Ruru, Kotuku, Kiwi, Kea, Huia and Elizabeth Jane.

The remaining six were Sunraysia, Red Ensign, Crimson Glory, Red Damask, Gaiety Girl and Snow White.

Tip cuttings were taken every three weeks from May 1983. Each cutting was stripped of its lower leaves, wounded and dipped in Seradix No 3, the centre's advisory outline syas.

After sticking, the cuttings and media were drenched with Benlate 1g/l. They were placed in Plixitrays filled with fibremix bark and then set on a capillary bed with 20 degrees bottom heat.

Automatic overhead misting was controlled by a filter paper leaf with shading provided on very bright days. The glasshouse was maintained at 16 degrees night and 18 degrees days, with venting at 18 degrees night and 22 degrees by day.

After six weeks the cuttings were assessed for root formation, the resource says.

"The results of this trial indicate that the success of rooting is dependent on both the variety and the time of taking the cuttings. The dwarf varieties rooted best during the months of September - January while the standard varieties showed the poorest rooting during this time.

"When cuttings had rooted, they were lifted and potted in 25-30mm pots with sphagnum/pumice 50/50 media. This media was used to aid overcoming quarantine regulations but fibre-mix bark or fibre-mix bark/pumice could be used.

"Once established they are liquid fed every three weeks )Alsaska or itrophoska).

The terminsl bud and any flower buds are removed, and further root and shoot growth is removed (at approximately three weekly intervals during the growing season) until the desired shape has been achieved."

Steve describes the project as prograssing on several fronts at present.

The volume continues: "An in-depth study of flowering in Leptospermums is underway to determine timing and environmental conditions which cause floral iniation. This is necessary so that the material can be produces ready for sale at the peak buying periods of the overseas customers."Trial shipments of Leptospermums in 75mm pots have been sent to Japan to assess packaging and transport problems, and quarantine problems.

A local firm has developed packaging aimed at avoiding spillage during shipping. Another company has produced special small pots and display trays.

Apart from overcoming quarantine problems, all that remains for minipots to edge some of their giant cousins off the retail shelves is for growers to take up their production seriously.

Steve is opeful this will happen by next year, with several commercial hoticulturalists gearing up now to turn out minipots.

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