Image
Image

Plant containers

Introduction

This theme considers AIR-POTS and BIODEGRADABLE POTS, exemplified by Superoots® of Caledonian Tree Company Ltd (gb) and Vipot® by Future Power Srl (I) respectively for reasons of enhanced root growth due to air-pruning and the ability of pots to naturally decompose in the soil due to manufacture from biopolymers and other biodegradable materials. These two product typologies demonstrate revolutionary (discontinuous) innovation.

Other plastic AIR-POTS are more rigid with air-spaces in the side walls. Examples demonstrate vertical corrugation and air slots in the side-walls. Another type has burlap side-walls with horizonal air-spaces as the diameter reduces. One final example, is made from a non-rigid porous fabric that can be folded flat and re-utilized. What types are best suited for ornamental horticulture and nursery-stock production?

For BIODEGRADABLE POTS, there are a great many variables to consider. Are they made of natural materials such as peat or bioplastics (biopolymers)? Are they sufficiently rigid for normal handling and mechanized production systems? How does the material perform under irrigation, especially when placed on capillary matting or under ebb-and flow irrigation? To what extent do they naturally biodegrade in the soil and how quickly do they biodegrade when discarded? Finally but not least are they internationally certified (certified as being environmentally friendly e.g. MPS). A look at this theme provides some answers and will raise new questions that address ecological aspects and the circular economy.

Q.1 What are some typical problems when trying to introduce innovative products to the horticultural sector?

We chose the ‘Superoots’ Air-pot manufactured by The Caledonian Tree Company (CTC Ltd) as an example. www.air-pot.com The new container offers advantages in terms of finished plant quality but is more expensive than ordinary pots.

It takes time for growers to appreciate the practical advantages of the new pot over several production cycles and even longer. Growing plants is a conservative business, having arrived at successful production techniques for specific plants, growers are naturally loathe to make changes and to spend more money. They also want to know what plant varieties benefit most from the new pot. In the meantime, understandably, supply companies of conventional containers can advise their grower clients against new products. This is particularly true in Italy where representatives of supply companies often tend to provide the technical advice.

It takes even longer for marketing and sales to address all relevant market segments (production, landscaping, wholesale and retail) and to obtain a premium price also from customer willingness to pay more for the extra plant quality obtained using the new container. This type of innovation tends to make slow but steady progress on the market through continued technical trials, commercial uptake and promotion. The manufacturer/ supplier needs substantial resources and great perseverance to keep pushing the merits of the new product internationally. Suddenly, often after a long and protracted period of time, the momentum of its utilization and promotion breaks down the resistance and the product enjoys faster and wider market acceptance.

This long introduction time-lapse is more common with important innovation since it requires reform of traditional thinking and practice. Other similar products are then given an already created ‘acceptance platform’ on which to compete.

Q.2 What environmental influences does a root system experience?

Roots are subject to abiotic stress factors, from soil-moisture to temperature, gaseous exchange, pH, mineral elements, organic chemicals and ionic charge. Added to this is mechanical and hydraulic stress exerted on roots by periodic water stress and drying of the soil. Biotic stress factors include: soil microorganisms, bacteria, fungi, viruses, nematode worms and insect larvae. When this complex ‘plant stress dynamic’  arrives at a natural balance, albeit temporary and within certain limits, plants are able to grow and thrive. Much less research has been made on roots and the root-zone in comparison to the aerial parts of plants.

In the case of ornamentals, positive effects on growth are obtained by utilizing different types of containers, cultural regimes and plant chemicals from fertilizers to anti-stress substances. There has been a slow and steady increase in the use of containers or ‘Air-Pots’ with punctured side-walls that cause ‘air-pruning’ of roots as a result of stress.

Q.3  What effect does air-pruning have on root systems?

The stress suffered by the root tips near the air holes, stimulates the synthesis of abscisic acid (ABA) which acts as a signal mediating a variety of responses. The most important result for the grower is the differentiation and growth of new outward pointing fibrous roots along the original roots to the base. These fibrous roots are all potential feeder roots. The response can be so strong according to Caledonian Tree Company Ltd that from any one original root that is air-pruned, 5- 10 new fibrous roots grow out into the substrate. This is a huge multiplying effect that results in the fast development of a thick fibrous root system, able to take up more water and minerals than a conventioned grown root system and better resisting transplant stress.  It also allows a reduced number of transplant stages and avoidance of spiral rooting.

The response varies with species but the general overall result is very positive, even in genera such as Eucalytus that ordinarily produce very dominant tap roots. More trials with air-pruning containers should be made on growing tropical plants in these containers e.g. Ficus spp, Palms, Dracaena, Croton etc

Q.4 What do ‘Superoot’ containers (the Air-Pot) consist of?

They are made from rolls of pre-determined lengths to create a cylindrical container. This makes it easier to wrap around the sometimes irregular root balls of large trees. Some smaller sizes are available already made up which contain a bottom net. The profile of this recyclable polyethylene material consists of closed inward pointing cones and open-ended outward pointed cones. The former guide the roots toward the air holes. The material is based on an original Australian patent and the name ‘Air-Pot’ is registered by CTC Ltd.

Q.5 After many years of grower scepticism regards the cost effectiveness of Air-Pots the predominant opinion today favours their use, especially in the production of high quality woody plants.What have growers found to be the advantages?

Commercial trials have clearly demonstrated that these Air-pots reduce production time also improving the final quality of the plants. Growers can now produce young stock from seed or cuttings in small Airpots (Air-Cells) through to medium and mature trees with large rootballs. Root spiralling is avoided. Jamie Single, CEO of CTC, adds that 30% more compost by weight can be packed into their Air-Pots (due to the light plastic protuberances). This means that plants can be left to grow in the same container for 2 years rather than one. Plants can be stored for much longer periods without suffering damage and an good fibrous root system reduces transplant stress. Greater air density in the substrate favour microorganisms that in turn guarantee healthy root growth. One practical problem is associated with potting or wrapping root systems in the field because for larger sizes there is no bottom piece. This is a problem until the root system is sufficiently developed to hold the root ball in place. Air-Pot

To complete the theme, other manufacturers produce plastic Air-pots are rigid with air-spaces in the side walls. One example from NSI & Poepplemann is the Accelerator® pot with vertical corrugation and air slots in the side-walls.  From Pasquini e Bini SpA (PT ) is the Varia® and Ercole® range. A variation on a theme is presented by Riverside Native Trees (USA) with an Air-pot with burlap side-walls with horizonal air-spaces as the diameter reduces. One final example, Vigoroot® is made from a non-rigid porous fabric that can be folded flat and re-utilized.

BIODEGRADABLE POTS

Manufacturers have introduced biodegradable pots that should be viewed in terms of  their characteristics listed below. In recent years, some manufactueres have resorted to 100% recycling of consumer plastic waste in order to maintain traditional grower performance and price of pots. These pots are blue in colour to be easily distinguable. Desch-Plantpak www.poeppelmann.com Biodegradable pots are usually more expensive, performance under various conditions (e.g. potting machines, ebb & flow irrigation, field) is variable and they often biodegrade only by composting. In the meantime, manufacturers such as Desch-Plantpak are trialling a bio-pot that fully degrades in the soil. A sample seen at the MyPlant & Garden exhibition, Milano, MyPlant&Garden was heavy with thick rigid sidewalls.

The list represents a daunting number of features from which manufacturers must choose their priorities. The main emphasis has been finding appropriate sources of vegetable biomass to provide  biopolymers used in the moulding. Starch from potatoes, maize, sugar cane, fibres from bamboo, coconut and Miscanthus, rice husks and material from vegetable oils are examples. More recently, following significant research in the plastics industry, it has become possible to ‘hybridize’ biopolymers with small amounts of non-renewable, petrol based polymers, that are also totally biodegradable, just enough to add some important sought-after characteristics. An example of the latter is Teku’s Natur’pot made 80% potato and maize starch plus a non renewable biodegradable polymer.

Q1. What then are the ideal characteristics for a biodegrabale plant pot or container in order to meet the needs of growers, distributors and final consumers?
  • Evident or easy to stimulate customer preference and willingness to pay more than for conventional plastic pots;
  • Strong and sufficiently rigid for use in automatic potting machines as with conventional pot;
  • Resistant to cracking, fungal degredation, resistant to softening under various types of irrigation used in production;
  • Shiny, professional surface available in a range of colours that can be printed upon or imprinted;
  • Porous side-walls that will enable air to penetrate the rootball thereby assisting respiration for roots and substrate microorganisms and improving root growth;
  • Low carbon footprint in terms of materials used and in the production process;
  • Made from plant waste rather than from crops grown specifically or which could otherwise be used as food;
  • Biopolymer made from biologically grown biomass to ensure the absence of pesticide and other chemical residues and from non OGM varieties. Biodegradable pots can be important polluters on the path to production probably due to plant chemicals (fertilizers, pesticides etc.) used in the production of the original biomass and the chemical processing needed to convert the biomass to biopolymers.
  • Fully 100% biodegradable that are compostable at ordinary temperatures;
  • Flexible production characteristics in terms of durability relating to the condition of the biopolymer utilized in moulding. A pot plant grower will be content with a pot that maintains its features for just one year, a nurserystock grower will want up to 4 or even 5 years for large container shrubs. This flexibility should extend to the possibility of manufacturing pots in different sizes and shapes in relatively small quantities according to the needs of grower clients.

Obtaining such desirable characteritics at a price acceptable to the grower and consumer has however proved difficult for several reasons. Firstly the performance of some bio-pots in mechanized production systems is not acceptable. Some pots do not biodegrade in the soil and need to be composted. Some biodegrade only after after the pots has been broken into small pieces. Others do not perform well in ebb and flow irrigation systems or in open air conditions. For this reason certain manufacturers of bio-pots have turned to recycling waste plastic 100% from consumer waste. These pots are usually blue in colour to be easily distinguable. However, research still aims to produce bio-pots that are strong enough, cost less and completely biodegrade in the soil.

Introducing innovation: biodegradable Vipot

Vipot is made 100% from rice-husks and a vegetable binder. This represents a huge quantity of organic waste throughout ther world. Rice-husks are known to contain high levels of silicon. It is possible (not yet proven) that the side walls might release small amounts of silicic acid because of root respiration and consquent acidification of the substrate. Mono-silicic acid is a beneficial anti-stress molecule in plant growth and development (See theme on bioactive silicon).

repowersrl.eu/#eutopia

The introduction of innovative products and systems is a key indicator in determining how well a country or company is able to navigate the barriers of established practice, bureauracy and vested interests, to economic success.

The example of the biodegradable Vipot in Europe demonstrates the difficulty in convincing growers that it is worthwhile to enter the argument of sustainable agriculture and biological production, saying no to plastics. See (PT) supplier Future Power Srl.

One of the difficulties arises from the gradual evolution in consumer behaviour.  Following introduction, the consumer tends to be excited and happy to pay more for a biodegradable pot. Then comes disillusionment born from confusion and contradiction in the claims made for many competing products. Consumers then start to understand the complexities of the ‘bio’ and ‘eco’ labelling and look for the pros and cons involved. With further education, the consumer becomes enlightened, able to place the advantages of an innovative product properly in context. Only then can the distributor, grower and consumer feel happy and confidant about the new product.

At the 2013 IPM exhibition at Essen, the Eutopia brand was launched. This brand consisted of a range of aromatic and flowering plants grown in Vipots by a consortium of growers and other professionals. Eutopia growers used Vipots and subscribed to precise production protocols. This very attractive trademark brings to bear from its Greek origin the idea of a good place to be, the contribution that the consortium and its brand intend to make in respect of nature and the environment. www.futurepowersrl.eu/#eutopia

While this consortium is no longer operative as in the first years, the brand and trademark await an alternative group to establish production of a range of aromatic herbs and vegetable plants in Vipots, linked to biological production and particular culinary uses. ‘Bonsai’ olive plants and Citrus varieties might be found suitable and a non-culinary group could include certain wildflower species, roses and orchids. In support of the brand, any such consortium needs to take care of the overall quality, uniformity and presentation of the plants themselves. Otherwise the brand is unlikely to meet its notable market potential.

Q.2 What can we learn from how Vipots are being introduced in Europe?

Vipots, made from waste rice husks, are 100% biodegradable (in time). They contain no synthetic additives and therefore leave no chemical residues in the soil or compost.  Made in China, these pots were first introduced in Europe by Fargro at the 2003 edition of the Four Oaks Exhibition www.fouroaks-tradeshow.com (PT) creating great interest and winning a prize for innovation.

It would however seem a contradiction in terms of marketing and promotion for the same distributor to sell Vipots alongside a wide range of plastic pots, except that they can easily reach their existing clientela.  It remains an uphill task to convince important propagators and growers about the merits and extra cost Vipots and much depends upon consumer education and preference to create market pull.

I next came across Vipots at the 2007 edition of the Flormart exhibition, Padova, Italy, on the stand of Total Packaging Srl that has the distribution rights for Europe (excluding UK). This Company is demonstrating a positive attitude for the introduction of innovative products, committing itself to success. (PT) See: www.flormart.it Vipot containers (Decor range bowls) were on display at the 2012 edition of Terra Madre / Salone del Gusto, Torino 2012 on the Biodiversity in Asia stand. The combination of rice grains (over 100 varieties) and containers made from rice husks was perfect and sets the scene for future international collaboration. See: www.slowfood.it

Q.3 What are the needs of the grower customers, diversified by sector and types of plants?

Future Power Srl shows strong determination to understand the precise needs of propagators and growers in Italy and in the rest of Europe. The Company has introduced Vipots designed for rooting young plants. Rooted young plants can be directly transplanted into the final Vipot (or into the ground) and the rooting-pot biodegrades in the substrate or soil. In a larger pot size they have introduced two new Vipots specifically designed for growing orchid and rose plants. This is the result of a close collaborationwith the manufacturer.

An important need for growers is to know the time it takes for Vipots to biodegrade; propagators seek around 12 months, a pot plant grower might ask for 18-24 months, while a nursery-stock grower wants a duration of 3-5 years for plants standing outside in all weathers. To some extent it is possible to tailor the duration by varying the consistency of the biopolymer, at source. For the florist and garden centre retail, a different more elegant range is available where the biopolymer has been further ‘cooked’ to provide a tougher, shiny surface and longer life.  Below image: note the rooting pot inside the final pot.

It should be said that for longer-life Vipots it is necessary to crack and break up the pots to ensure rapid bidegradation, providing a larger surface area for the soil microorganisms to do their work. In the USA, environmental organizations are attempting to specify the maximum period for degradation if to call a product biodegradable. No doubt there are some vested commercial interests in this regard, although it is increasingly necessary to counter ‘green washing’ – where companies promote products as being ecologically and environmentally sound/sustainable without any real scientific basis. As the Vipot material degrades, it releases mineral nutrients, organic fibre (and no chemical residues) to the benefit of soil fertility.

Q.4 Circular Economy: How is it possible to link biological production, bioenergy and biodiversity?

The controlling company FuturePower Srl, also distributes Biogas technology, enabling the company to commit growers to a virtuous C2C (cradle to cradle) recycling concept.  From waste rice husks to Vipots, from plants grown biologically in Vipots to surplus plants and waste, from biogas digestors to the production of electricty, hot water and plant compost.  See: biodiversity & energy (pdf English) and biodiversità ed energia (pdf italiano) and section on biogas.

Q.5 Meeting the need for applied research?

Greenhouse and laboratory research is another aspect not overlooked by the Company. Research Institutes need new research projects for their students and professors and Vipot is happy to engage in comparative research. Positive results in Italy speak for themselves and will help growers appreciate the characteristics of the pots and accept a slightly higher unit cost (due not to the material itself but to the current limitation in speed of production).

Research undertaken by FloSo at the University of Padova (Dipartimento di Agronomia Ambientale e Produzioni Vegetali) on Pelargonium, Cyclamen and Poinsettia, in association with commercial nurseries. For example in the Cyclamen tested, the fresh weight of the vegetation and the root system increased in plants grown in Vipots against the controls. See also the comparative research undertaken by the University of Basilicata on two biodegradable pots on the cultivation of Poinsettia See: Poinsettia in Vipot pdf (ItalianoPoinsettia in Vipot pdf (English)

Vipots are porous to gaseous exchange which has a positive effect on the growth of roots and reducing root spiralling. The positive effect extends to the growth of populations of microorganisms, antagonist to potentially pathenogenic organisms. The same might be said of clay pots but these have the disadvantage of weight and coldness in the winter.

Q.6 Why do some doors open while others stay doggedly closed, for no discernable reason?

Not least is the barrier to innovation represented by corporatism. The organization of horticultural professionals into corporate groups and associations should be based on common interests. Companies naturally seek to collaborate with such organizations, but growers and other operators can be easily conditioned by pressure from the agrochemical and plastics industry or by opinions and vested interests of leading figures, if left uncontested for long.

A reportfrom the US Natural Marketing Institute (NMI) 2012 says that negative perceptions of environmentally friendly products is keeping an increasing number of consumers out of the market even when more people know about these goods and where to find them. The data shows that the trade is past the point of being able to charge more for green products! It has to make the value and benefits clear to consumers – saving the planet is not reason enough to charge more. In addition, consumers often perceive that environmentally friendly products do not work as well as regular products. It is necessary to demonstrate the value of environmentally friendly products by driving the costs down, improving quality, and communicating the benefits, if the growth of the green marketplace is to continue. LOHAS Consumer Trends Database: (Lifestyles of Health and Sustainability).  GrowerTalks/Green Profit Ball Publishing  www.nmisolutions.com

Despite the above, consumer research in the USA has shown that of all the different types of biodegradable pots tested, Vipot (US equivalent) had the highest rating with clients to accept the extra cost at retail.  This cannot be immediately extended to Italian and European consumers without further research, nevertheless it remains a useful indicator for retailers to inform their grower suppliers. Premium price pdf (EnglishPremium price pdf (Italiano)

The combination of marketing and promotional efforts of an entrepreneurial company together with research and communication, demonstrates the way forward for introducing truly innovative products and to win over conventional thought and resistance.

Q6. What other biodegradable pots are available?

Biopots_image_Purdue uniThere are many different Biopots for growers to choose from. Characteristics vary consideranbly in terms of the renewable resources utilized, additives, relative ability and speed to biodegrade and their compostability. In some cases the pots need to be crushed into smaller pieces to aid biodegradation. At all events the following Biopots come from large well-established manufacturers able to introduce this innovation to existing clients.

Comparative trials have been made between some of these Biopots. Institutional trials include: the IQDHO, Quebec (Quebec Institute for the Development of Ornamental Horticulture) reported in ‘Quebec Vert, September-October 2010 by authors Nicolas Authier and Louise O’Donoughue (Text in French followed by English, pdf). The University of Tennessee, Extension Services provide an excellent reference in a series of articles on trials with Biodegradable pots Part 1, Part 2, Part 3, Part 4  For other references see the Ellison Chair in International Floriculture and further research in article published in Hortechnology June 2010 June 2010 20(3) 549-555, ‘Physical Properties of Biocontainers for Greenhouse Crop Production’ by Michael Evans, Matt Taylor and Jeff Kuehny. A report by the University of Massachusetts Amherst Extension presents further information. See also an article in GreenHouse Grower Octobe 2010 by Diane M Camberato and Roberto G Lopex entitled ‘Biocontainers for Long-Term Crops.

Some other propriety products and materials

Different renewable source materials and mixtures have been used to provide biopolymers.  Potato starch is used in the Nature Pot from JD TransBIO www.jdtransbio.fr and Napac’s BioPot (PT) is produced 70% from Miscanthus or rice fibre mixed with a natural binder. See also Clamer Informa newsEcovas pots use unspecified vegetable oils.   From Desch (PT) D-Grade Bio products are 100% biodegradable and compostable produced based on vegetable materials and are completely free from genetically modified materials. Ball Horticultural Company’s Soil Wrap is made from maize biomass.

Q8. How can we judge the Carbon Footprint of Biopots?

Which pots have the lowest carbon footprint? In this difficult analysis various factors need considering: Gains made by substituting fossil fuel with biomass. Gains made by using organic waste thereby reducing costs and pollution involved in waste disposal. Gains from low energy input and use of renewable energy in the manufacturing process. Gains made from using biopolmers free from chemical residues.  What pots can be simply thrown into anaerobic digesters, together with unsold or dead plants, generating biogas? Others are compostable only at higher temperatures in industrial composting. See Report on the Appeal of Biodegradable Packaging pdf sponsored by the American Floral Endowment.

Q9. Are biopots all ‘Green’?

The bioamass used in the manufacture of Biopots also needs to be grown biologically. An examination was made of 12 polymers – 7 derived from petroleum, 4 from plant sources and one derived from both – for their environmental impact both in terms of the production and preproduction of the polymers themselves and their life cycle or biodegradability. As could be expected, biopolymers won out in terms of biodegradability, low toxicity and the use of renewable sources of energy. Suprisingly, however, biopolymers were amongst the greatest polluters on the path to production, probably due to plant chemicals (fertilizers, pesticides etc.) used in the production of the original biomass and the chemical processing needed to convert the biomass to plastic polymers. Michaelangelo D. Tabone, James J. Cregg, Eric J. Beckman, and Amy E. Landis, Environ. Sci. Technol., 2010, 44 (21), pp 8264–8269 DOI: 10.102/es101640n University of Pittsburgh, USA. News.pitt.edu LCA

Edward Bent ©2012/2018 | HORTCOM

FRUIT OR VEGETABLE?

Calvenzano melons are large, weighing in at 2-5kg (the record is 6kg) elongated with a strongly netted exterior or rind, and crisp, orange flesh. Calvenzano is a small town in

Share
SMALLER FLOWERS VERSUS LARGER ONES

It is not surprising that wildflower species adopt a trade-off in terms of their potential to adapt to changing environmental conditions and one of these factors is smaller flowers. Gardens

Share
SUSTAINABLE GREENHOUSE CULTIVATION

Two new books, written in English, are certain to make a big contribution to modern-day, greenhouse cultivation. The first of these, published October 2019 by Burleigh Dodds Science Publishing Ltd,

Share
SILICON CONTINUES TO SURPRISE

The bioactive molecule of this element, mono-silicic acid, continues to surprise and is the subject of an extensive literature in the HORTCOM theme Silicon in Agriculture. It has been shown

Share
FEEDING THE WORLD WITH TOMATOES

Today, the huge expansion throughout the world in the build of large greenhouse units, from Mexico to China, Kazakistan to Canada to Qatar, is more than evident. Cravo Equipment Ltd,

Share
UV-B AGAINST FUNGAL DISEASES

UV-B lighting controls powdery mildew in protected strawberry crops and powdery mildew and gray mould in tomatoes. A new type of UV-B fluorescent lamp, recently developed by the Panasonic Lighting

Share
Image
Image