Actual Performance versus Theoretical Advantages of Polyacrylamide Hydrogel throughout Bedding Plant Production

An appropriate blend of growing media components increases water holding capacity and reduces irrigation frequency. Synthetic commercial materials, referred to as hydrogels, have remarkable hydrating properties, but can add significantly (about 15%) to the cost of growing media. The literature generally states that the physical characteristics of hydrogels, such as polyacrylamide (PAM), are altered by the presence of divalent cations (Ca2+ and Mg2+). Few studies, however, have simultaneously investigated plant growth and development and media characteristics on a daily basis throughout plant production. Thus, the mechanisms explaining the reported beneficial and/or detrimental effects from PAM incorporation remain hidden. In this study, canopy ground cover of two species [pansy (Viola ×wittrockiana Gams) and new guinea impatiens (Impatiens hawkeri Bull)] was measured daily, from transplanting to marketable size, using digital imaging to determine growth differences of plants grown in media containing different amounts of PAM. Media water content was determined with time-domain reflectance probes every 10 minutes in media treatments. Total number of irrigation events, time between irrigation events, root development after 4 and 8 weeks of growth, flower number, flower longevity, and dry masses of the shoot were also measured. Scanning electron microscopy revealed significant structural differences in hydrated PAM depending on water quality. The pansy canopy coverage was significantly greater with hydrogels, and root growth early in production was enhanced with PAM. No such effect was observed for new guinea impatiens. Total flower numbers and flower longevity of new guinea impatiens decreased with increasing amount of PAM (16.7% or higher) in the media. PAM incorporation reduced the need for irrigation early in production for both species, but by the end of production, those new guinea impatiens plants were smaller (less shoot dry mass) and required irrigation as often as plants grown without PAM. This effect coincided with reduced media volume, air capacity, and total porosity in PAM-containing media. Theoretical analysis of the potential benefits from hydrogels confirms the potential benefit early in production with little to no benefit later in production and in post-production. These data will assist growers in determining if the benefits derived from the use of PAM justify the added cost of medium.

Download Full-text

A biotic strategy to sequester carbon in the ornamental containerized bedding plant production: A review

Spanish Journal of Agricultural Research ◽

10.5424/sjar/2018163-12871 ◽

2018 ◽

Vol 16 (3) ◽

pp. e03R01 ◽

Cited By ~ 6

Author(s):

Jose M. Alvarez ◽

Claudio Pasian ◽

Rattan Lal ◽

Rafael Lopez-Nuñez ◽

Manuel Fernández

Keyword(s):

Carbon Sequestration ◽

Ghg Emissions ◽

Industrial Sector ◽

Plant Production ◽

Peat Moss ◽

Growth Media ◽

Growing Media ◽

Row Crops ◽

Bedding Plant ◽

Wide Range

Identifying options of climate change mitigation is of global interest to researchers. Whereas wide range of techniques of reducing greenhouse gas (GHG) emissions and carbon sequestration have been studied in row crops and forest systems, little research has been done on the ornamental horticulture. The ornamental industrial sector has indeed some negative impacts on the global environment, but also presents opportunities to reduce GHG emissions and increase C sequestration. Thus the objective of this study was to synthesize the potential contributions of some substrates used in the horticultural sector to carbon sequestration. The specific focus of the review is on the possible use of compost, vermicompost and biochar as soilless substrate substitutes for containerized ornamental plants production. Around 11 million kilograms of sphagnum peat moss are used annually in the world for horticultural production. Therefore, the potential of using compost, vermicompost and biochar as growing media is assessed on the basis of data from greenhouse studies. Peat-based substrate can be substituted up to 30% to 35% by compost or vermicompost and up to 20% to 25% by biochar. Some examples from field studies are included to conduct the life cycle assessment of using these growth media. An estimate of C storage on the long-term basis in soil indicates up to 3 million tons of CO2 equivalent as the maximum C potential storage per year in the global productive sector if the peat-based growing media are substituted by compost/vermicompost and biochar at the ratios mentioned above. Finally, synergies between compost vermicompost and biochar are discussed when these materials are combined as growing media additives and research gaps in this area of activity have been identified for further research.

Download Full-text

The effect of irrigation frequency on growth, flowering and stomatal conductance of osteospermum 'Denebola' and New Guinea impatiens 'Timor' grown on ebb·and-flow benches

Acta Agrobotanica ◽

10.5586/aa.2001.023 ◽

2013 ◽

Vol 54 (2) ◽

pp. 59-68

Author(s):

Jadwiga Treder ◽

Joanna Nowak

Keyword(s):

Water Stress ◽

Stomatal Conductance ◽

Water Potential ◽

Growth Parameters ◽

Soil Water Potential ◽

New Guinea ◽

Growth Stages ◽

Irrigation Frequency ◽

Growing Period ◽

New Guinea Impatiens

The response of osteospermum 'Denebola' and New Guinea impatiens 'Timor' grown on ebb-and-flow benches to different water potential of growing medium applied during whole growing period was investigated by measuring plant growth parameters and stomatal conductance (g<sub>S</sub>). After cutting establishment, four different irrigation treatments based on soil water potential were applied to osteospermum: at -0,5 , -3,0 , -10,0 , -20 kPa. In the case of impatiens the last water treatment was omitted. Plants were evaluated when they reach one ofthe three growth stages: lateral shoots development, visible flower buds (osteospermum) or beginning of flowering (impatiens) and at flowering. All plants produced with a moderate water deficit (irrigation at -3 and -10 kPa) were more compact than plants irrigated at -0,5 kPa but their flowering were not affected. Strong decrease in pIant growth and flowering was observed when plants were irrigated at the lowest water potential (-20 kPa). However, for impatiens the highest irrigation frequency was also not favorable. As a result of water stress the decrease in stomatal conductance (g~) in both plants was observed. Osteospermum was more resistant to water stress than impatiens.

Download Full-text

New Guinea Impatiens Flower Life and Growth Response to Coal Bottom Ash Level in the Root Substrate

HortScience ◽

10.21273/hortsci.33.3.465c ◽

1998 ◽

Vol 33 (3) ◽

pp. 465c-465

Author(s):

Dharmalingam S. Pitchay ◽

Marlene Cross ◽

Bradford C. Bearce ◽

Edwin Townsend

Keyword(s):

Growth Response ◽

Bottom Ash ◽

Net Photosynthesis ◽

New Guinea ◽

Flower Longevity ◽

Quality Indices ◽

Flower Opening ◽

Coal Bottom Ash ◽

Leaf Chamber ◽

New Guinea Impatiens

On 26 Mar. 1997, New Guinea impatiens (Impatiens × New Guinea) cultivars `Aglia', `Anaea', `Bora-bora', and `Dark Delias', were planted in 1 peat: 1 vermiculite (v/v) rooting media containing 0%, 25%, or 50% by volume of coal bottom ash (CBA) that had been sieved through 6-mm mesh. Individual flower longevity was recorded from the first day of flower opening until senescence. There was no significant effect among levels of CBA on flower longevity. However, flower life varied significantly among cultivars from 9.5–9.9 days in `Aglia' to 15.1–15.8 days in `Dark Delias'. Per-plant bloom numbers increased linearly with increase in percent CBA for all cultivars. Plant diameters were reduced by CBA in `Aglia', but not affected by CBA in the other three cultivars. Plant heights of `Dark Delias' were increased at 50% CBA over that of plants in 0% CBA. Visual quality indices were significantly greater for plants in CBA media compared to that for plants in 0% CBA. Top fresh and dry weights within each cultivar were equal among CBA levels. Within cultivars, there were no significant differences among plants at different CBA levels in plant transpiration rate, stomatal conductance, and net photosynthesis when measured with an LCA3 Leaf Chamber Analyser. However, there were significant differences in these processes among cultivars.

Download Full-text

KENAF AS A COMPONENT OF SOILLESS GROWTH MEDIA

HortScience ◽

10.21273/hortsci.28.4.256c ◽

1993 ◽

Vol 28 (4) ◽

pp. 256C-256

Author(s):

Bing Shi ◽

Wallace Pill

Keyword(s):

Shoot Growth ◽

Slow Release ◽

Total Porosity ◽

Hibiscus Cannabinus ◽

Plant Production ◽

Growth Media ◽

Calcined Clay ◽

N Supply ◽

Bedding Plant ◽

Optimal Medium

Kenaf (Hibiscus cannabinus L.), native to east Africa, is an annual herbaceous member of Malvaceae cultivated primarily for its bast fibers. One of many potential uses of kenaf is that of a growth medium component. Kenaf stems (xylem plus phloem) were ground and sieved to 2 to 5 mm diameter particles. The particles were combined at various volumetric percentages with other components (perlite, vermiculite, calcined clay) in 70% Sphagnum pest moss which received standard preplant fertilization. To avoid growth suppression, the kenaf must be enriched with nitrogen (soaked in NH4NO3 solution for 5 days). Impatiens and tomato bedding plant shoot growth was proportional to both the N concentration of the soak solution and the percentage of N-soaked kenaf in the medium. The N soak solution should be £ 2000 mg N/liter with 30% kenaf or £ 4000 mg N/liter with 10% kenaf. Physical properties (bulk density, total porosity, air porosity and container capacity) of kenaf media were similar to those of a commercial peat-lite. The optimal medium for bedding plant production was 70% pest + 15% calcined clay + 15% kenaf soaked in 2000 mg N/liter. The N-soaked kenaf served successfully both as a medium bulking component and as a slow-release N supply.

Download Full-text

Growth of Geranium Plants in Soilless Media Containing Sphagnum Peat and Anaerobic Digestion-Derived Biosolids

HortScience ◽

10.21273/hortsci.41.4.979c ◽

2006 ◽

Vol 41 (4) ◽

pp. 979C-979 ◽

Cited By ~ 1

Author(s):

Michael Compton ◽

Timothy Zauche

Keyword(s):

Anaerobic Digestion ◽

Dry Weight ◽

Plant Production ◽

Growing Media ◽

Complete Replacement ◽

Soilless Media ◽

Sphagnum Peat ◽

Bedding Plant ◽

Normal Light ◽

Technology Foundation

Anaerobic digestion-derived biosolids (ADB) has the potential to become a complete or partial substitute for sphagnum peat in the greenhouse and nursery industry. Bedding plant production being one of the largest segments of the floriculture industry may possess the greatest application for this new organic addendum to soilless media. An experiment was conducted in which geraniums (Pelargonium ×hortorum `Red Elite') were grown in potting mixes formulated with vermiculite and perlite plus various concentrations and combination of anaerobic digestion-derived biosolids (ADB) and sphagnum peat to determine if ADB could be used as a partial or complete replacement for sphagnum peat in soilless horticultural growing media. Plants were grown during June and July 2003–05 in the greenhouse at 75 ± 5 °F and normal light and photoperiod. Plant growth was assessed by measuring the dry weight of stem tissue. Plants were harvested when at least 50% of the total number of plants produced at least one inflorescence. Floriferousness was measured by counting the number of visible inflorescences per plant. Dry weight of plants grown in media containing ADB was greater than those grown in media containing sphagnum peat as the sole organic addendum. Plants grown in media containing ADB were also more floriferous. This study demonstrates that ADB has great potential for use as an organic addendum to horticultural growing media as a partial or complete replacement for sphagnum peat. Use of anaerobic digester-derived biosolids in horticultural growing media is a protected intellectual property and available for license through the WiSys Technology Foundation.

Download Full-text

Greenhouse bedding plant production of Stevia rebaudiana (Bert) Bertoni

Canadian Journal of Plant Science ◽

10.4141/p96-166 ◽

1997 ◽

Vol 77 (3) ◽

pp. 473-474 ◽

Cited By ~ 15

Author(s):

J. W. P. Carneiro ◽

A. S. Muniz ◽

T. A. Guedes

Keyword(s):

Key Words ◽

Stevia Rebaudiana ◽

Laying Hen ◽

Plant Production ◽

Growing Media ◽

Bedding Plant

The purpose of this experiment was to determine the effects of 14 growing media on greenhouse bedding plant production of Stevia rebaudiana (Bert) Bertoni. The best mixture consisted of sand clay (LEd2) soil, laying hen manure (10% vol/vol), and lime. Key words: Natural sweetener, fertilizers, transplant production

Download Full-text

Phosphorus Fertilization in Ebb and Flow Production of Bedding Plants

HortScience ◽

10.21273/hortsci.33.3.523b ◽

1998 ◽

Vol 33 (3) ◽

pp. 523b-523 ◽

Cited By ~ 1

Author(s):

Erin James ◽

Marc van Iersel

Keyword(s):

Dry Mass ◽

Plant Production ◽

Phosphorus Fertilization ◽

Time Interval ◽

Nutrient Runoff ◽

Growing Period ◽

Bedding Plants ◽

Lack Of Information ◽

Bedding Plant ◽

Ebb And Flow

The quantity and quality of available water in the Southeastern United States continues to decline as demands on limited resources increase. Growers will soon be forced to comply with legal limitations on water consumption and limits on nutrient runoff from their operations. A lack of information on standard growing practices using alternative irrigation systems such as ebb and flow is hindering their acceptance and implementation. We are currently conducting a series of experiments to establish basic growing guidelines for the use of ebb and flow in the greenhouse in bedding plant production. In the third of these experiments, Petunia × hybrida Hort. Vilm.-Andr. `Blue Frost' and Begonia × hiemalis Fotsch. `Ambassador Scarlet' were grown for 5 weeks on ebb and flow tables with fertigation solutions (225 ppm N) containing three different levels of phosphorus (0, 50, and 100 ppm). Three soilless media were also used, which varied in their percentage content of vermiculite, perlite, pine bark and coconut coir. For both the begonias and petunias dry mass of the shoot was greatest in plants grown with higher levels of phosphorus. In comparison to plants grown with 0 ppm phosphorous, petunias and begonias grown with 50 or 100 ppm P were 44% and 25% greater in mass, respectively. However, begonias had 38% more flowers when fertigated with the higher levels of phosphorous while petunias flowered earlier with 0 ppm P fertigation solution. The electrical conductivity of the media did not change significantly over the course of the growing period, but the pH dropped by an average of 1 over the same time interval.

Download Full-text