Potted Plant Production Research Articles

New Caladium Cultivars ‘Dots Delight’ and ‘Wonderland’

Caladiums are ornamental aroids valued for their vibrant and morphologically diverse foliage. Grower surveys indicated that they planted more acres of lance-leaved cultivars in recent decades to accommodate rising consumer demand. The caladium breeding program at the UF/IFAS Gulf Coast Research and Education Center has been developing new lance-leaved cultivars that can produce attractive, robust plants with many bright, colorful leaves and improved tuber yield potential. The program has recently released two new lance-leaved cultivars. ‘Dots Delight’ is well suited for use in sunny landscapes, having excellent tolerance to sunburn and strong resistance to the leaf spot disease. Though they may need one to two additional weeks to produce potted plants, tuber yield potential is intermediate to high. ‘Wonderland’ is well suited for potted plant production in sunny or shady landscapes or gardens and has showed good leaf color display, sunburn tolerance, and leaf health.

Estimating Nitrogen Release from Organic Fertilizers for Soilless Production by Analysis of C and N Pools

The use of organic fertilizers in soilless pot plant production has sharply increased in recent years. However, there is still a lack of methods for characterizing the N release from organic fertilizers. This bears the risk of an inadequate nutrient supply and, thus, a waste of resources. Therefore, the current research analyzed fourteen commercial organic fertilizers for various C and N pools by extraction in cold and hot water, acid hydrolysis, and thermal fractionation. Furthermore, we conducted an incubation test using a growing medium (80 vol% peat plus 20 vol% green waste compost) and fitted the nitrogen release to different kinetic models. Finally, we calculated the correlations among the best-suited kinetic model parameters and the C and N pools. The C and N pools soluble in water and weak hydrochloride acid varied significantly among the fourteen fertilizers but were closely correlated with each other. The N release from most organic fertilizers could be described very well using the Gompertz function (R² > 0.9), and the parameters of the Gompertz function showed significant correlations with the C and N pools. Hydrolyzable C and N pools provided valuable information about the N release characteristics of organic fertilizers.

Influence of container, potting media and nutrients on production and post-production consumer acceptance of potted marigold (Tagetes patula L.)

Production of potted plants is influenced by factors viz., type of container, potting medium, nutrient dose. A study was conducted to standardize these factors for potted French marigold var. Arka Pari. The treatments comprised of two type of containers (plastic and coir), three potting media [red soil + FYM + sand (1:1:1 v/v), Arka fermented cocopeat (AFC), AFC + vermicompost (1:1 v/v)] and four nutrition concentrations (160:30:180 ppm N:P: K, 128:24:144 ppm N:P: K, 96:18:108 ppm N:P:K and 3% Jeevamrutha) laid out in factorial completely randomized design replicated thrice. Plants grown in potting media combination of Arka fermented cocopeat (AFC) + vermicompost (1:1 v/v) along with weekly application of nutrient solution (128:24:144 ppm NPK) produced maximum number of flowers plant-1 (147.61) and registered highest uptake of nitrogen (2.87 g plant-1), phosphorus (0.53 g plant-1), potassium (3.24 g plant-1), magnesium (0.85 g plant-1) and sulphur (0.21 g plant-1). Based on the attributes of the potted plants, this treatment combination also registered the highest score (81.2 on a scale of 100), willingness of the consumers to purchase (4.5 on a scale of 5), overall acceptability (2.7 on a scale of 3) and the benefit cost ratio of 1.18.

Effect of different growing media and shade levels on pot plant production of Aglaonema modestum

Effect of different growing media and shade levels on pot plant production of Aglaonema modestum

Standardization of container type, substrate and nutrition for potted plant production of China aster [Callistephus chinensis (L.) Ness.] var. Arka Archana

A study was conducted at the ICAR-Indian Institute of Horticultural Research, Hesaraghatta, Bengaluru for three consecutive seasons during 2019-20, to standardize the container type, substrate combination and nutrition for potted plant production of China aster var. Arka Archana. The treatments comprised of two type of containers (plastic and coir), three substrates {Red soil + FYM + Sand (1:1:1 v/v), Arka Fermented cocopeat (AFC), AFC + Vermicompost (1:1 v/v)} and four nutrition concentration (160:30:180 ppm N:P: K, 128:24:144 ppm N:P: K, 96:18:108 ppm N:P: K and Jeevamrutha @ 3%) laid out in factorial completely randomized design with three replications. Plant height at flowering (33.12 cm), number of primary branches (12.4), plant spread (536.64 cm2), number of flowers/plant (26.47), flower size (5.26 cm) and uptake of major, secondary and minor nutrients were maximum in the plants grown in 6" plastic pots using the substrate combination of soil +sand +FYM (1:1:1 v/v/v) along with the weekly application of nutrient solution of 96:18:108 ppm NPK/plant. This production protocol resulted in a dense canopy and highly floriferous potted plants. The benefit cost ratio of potted China aster production was 1.70. This technology can be adopted by the nurserymen for large-scale commercial potted plant production.

Hidrogel como mitigador do estresse salino durante o estabelecimento de mudas de Tagetes patula L.

ABSTRACT Hydrogels favor moisture retention in the substrate and can attenuate the effects of salt stress on the production of potted plants. In this context, this research sought to evaluate the use of hydrogel to mitigate the damage caused by the salinity of irrigation water on the emergence, growth, and thermal index of Tagetes patula L. seedlings. The research was carried out in a greenhouse, in September 2020, in the municipality of Fortaleza, Ceará State, Brazil. The design used was randomized blocks in a split plot. The plots corresponded to seven levels of electrical conductivity of the irrigation water - ECw (0.5, 1.0, 2.0, 3.0, 4.0, 5.0, and 6.0 dS m-1) and the subplots corresponded to four hydrogel concentrations (0, 1.0, 2.0, and 3.0 g L-1), with five replicates and each subplot consisted of 27 seeds. The application of 3.0 g hydrogel L-1 of substrate favored the production of leaves and reduced the thermal index in plants associated with the increase in the salinity of the substrate up to 6.0 dS m-1. The use of 3.0 g L-1 hydrogel increases seedling height, leaf dry mass, and total dry mass compared to treatments without water-retaining polymer, even at moderate (2.0 to 3.0 dS m-1) and high (4.0 to 6.0 dS m-1) salinity levels, thus indicating a possible effect of mitigation of damage caused by the salinity of the irrigation water. However, the intensity of this mitigating effect decreases at higher levels of salt stress.

Concentration and Timing of Dikegulac Sodium on Helianthus hybrida ‘Sunfinity’ Seedlings for Potted Plant Production

Sunflower ‘Sunfinity’ (Helianthus hybrida) can be produced as a potted plant if apical dominance is removed with a manual pinch to control plant height and promote branching and flower number. Chemical pinching agents such as dikegulac sodium could prove to be valuable tools to reduce the labor and costs associated with manual pinching. Our objective was to determine the time of seedling growth and concentration of dikegulac sodium foliar spray application that would result in morphology similar to manually pinched plants. Dikegulac sodium was applied to sunflower ‘Sunfinity’ seedlings at one of four concentrations increasing from 200 to 500 mg⋅L−1 at the time of growth when the first, second, or third node (N1, N2, or N3) was the apical node and axillary stems at those nodes were undeveloped. Applications of 400 mg⋅L−1 at N3 and 500 mg·L−1 at N2 removed apical dominance because of total senescence of the apical meristem and produced a well-branched plant similar to that subjected to manual pinching. Apical dominance was temporarily inhibited without senescence of the apical meristem when 400 mg⋅L−1 was applied at N2 and when 500 mg⋅L−1 was applied at N3, which, nevertheless, resulted in branching that formed a well-rounded canopy.

Influence of Environmental Parameters, Pinching, and Ethephon Application on Growth and Branching of Potted Stevia

Stevia (Stevia rebaudiana) is an herb grown commercially for the extraction of intensely sweet-tasting, non-caloric, steviol glycosides produced primarily in the leaves and used as a sugar substitute. While most stevia production occurs as an industrial field crop, more recently, consumer demand for stevia for home gardens and patio containers has increased. Research on how environmental inputs impact growth, branching, and flowering of stevia under greenhouse conditions for potted plant production is currently lacking. A series of experiments was conducted to quantify how methods to promote branching, fertilizer concentration, photoperiod and temperature impact branch production, growth and development, and flowering of stevia. Both manual decapitation and ethephon application increased lateral branch production, though hard pinching (cutting plants back to leave four nodes) yielded a more desirable plant architecture. Neither temperature nor fertilizer concentration impacted the number of branches produced by plants given a hard pinch. Shoot dry biomass was similar at fertilizer concentrations (applied at each watering) of 50, 100, and 200 mg⋅L−1 N, but decreased at 300 or 400 mg⋅L−1 N. Stevia responded to photoperiod as a facultative short-day plant, with earliest flowering occurring, both in days to flower and the number of nodes produced before flowering, at photoperiods <13 hours. The number of nodes produced on the longest branch increased as temperature increased from 17 to 26 °C. Plant height and longest branch length were shorter at 17 °C than at higher temperatures. The results of these studies indicate that for potted plant production, stevia should be grown under a photoperiod of 14 hours or longer with moderate nutrient levels, a minimum temperature of 20 °C, and plants should receive one or more manual pinches to promote branching.

Effects of a Gibberellin Inhibitor on Flowering, Vegetative Propagation, and Production of Rapid Generation Cycling Gladiolus for Potted Plant Production

Gladiolus (Gladiolus ×hybridus) is an asexually propagated, herbaceous perennial and an economically important cut flower crop. In commercial production, gladioli have tall flower stalks, which limit their use to cut flowers and annual garden plants. The gladiolus breeding program at the University of Minnesota has bred and selected rapid generation cycling (RGC) cycle 1 gladiolus, which can flower in <1 year from seed instead of the norm of 3 to 5 years (which are vegetatively propagated as corms). Gibberellin inhibitors, such as ancymidol, are used as plant growth retardants to control height in potted plants. Higher concentrations can inhibit flowering along with other negative side effects. The aim of this study was to investigate the growth, flowering, and corm/cormel production response of cycle 1 gladiolus to the gibberellin inhibitor, ancymidol (0, 100, and 400 mg·L−1 soak) in comparison with noncycle 1 genotypes and commercial cultivars for potted gladiolus production. Cycle 1 genotypes flowered with all ancymidol concentrations while noncycle 1 genotypes had significantly fewer flowers or were completely nonflowering under higher concentrations. All tested genotypes had increased leaf width as ancymidol concentration increased. Conversely, flower stalk heights were shorter as the ancymidol concentration increased while the number of stalks was nonsignificant. Corms, cormel number, and fresh weights decreased in all genotypes except for one cycle 1 genotype, which had an increase in both corm number and fresh weight when treated with 100 mg·L−1 ancymidol. Cycle 1 gladiolus are more resilient to this gibberellin inhibitor even at high concentrations and can potentially be used for gladiolus potted plant production.

Water absorption analysis of a peat‐perlite horticultural substrate in response to various subirrigation conditions using a thermal imaging camera

Subirrigation systems are widely used in commercial greenhouses for efficient and high-quality production of potted plants. However, proper criteria of the water level and retention time need to be quantified for more efficient irrigation. This study analyzed the water absorption and vertical water distribution in a horticultural substrate in 10-cm pots under various subirrigation water levels and retention times. To analyze the water absorption dynamics, we continuously measured changes in the actual substrate volumetric water content using capacitance soil moisture sensors. The vertical distribution of water in the pot was measured using a thermal imaging camera, with a small temperature difference indicating more water absorption. As expected, the volumetric water content in the pots increased as the subirrigation water level and retention time increased; however, significantly less water was absorbed near the top surface of the substrate, and the variation of the vertical water distribution increased at lower subirrigation water levels or shorter retention times. This suggests that young plants with smaller root systems would require a higher water level and retention time for subirrigation if their roots are distributed near the top of the pot. This study provides a better understanding of water absorption and its vertical distribution across a horticultural substrate when using a subirrigation system and supports decision making for the suitable management of subirrigation conditions according to the type of plant species or crop growth stage.

Optimization of organic nitrogen fertilization in horticultural substrates for potted plant production (OptiFaz project)

Optimization of organic nitrogen fertilization in horticultural substrates for potted plant production (OptiFaz project)

The effect of a glass matrix fertilizer and compost amendment on plant growth and mineral nutrition of two container-grown Rose spp. cultivars

The production of ornamental potted plants usually involves high inputs of agrochemicals. However, high sustainability is now key to nursery production through the re-use of organic and inorganic waste material. The new European Waste Directives introduced ambitious goals to transform waste disposal from a need into an opportunity in order to create an economy capable of safeguarding the environment and promoting social awareness (Directive EU 2018/851).In this work, two different rose cultivars, the shrub ‘Knock Out®’ and the groundcover rose ‘The Fairy’, were grown using one of two waste products as growing media components and nutrition sources: i) a glass matrix-based fertilizer (GMF) added to the control substrate at a rate of 2 g L−1, and ii) a compost (CMP) derived from urban refuse, in partial replacement of the peat used for the control growing media (20 % v v−1).The effects on physico-chemical characteristics of the substrate on plant growth, tissue characteristics and plant mineral nutrition were assessed after a cultivation cycle of 330 days, from spring 2011 to spring 2012. Neither of the two treatments affected the substrate’s physical properties compared with the control. However, the content of essential nutrients, Al, Na and heavy metals increased, with some concerns regarding trace heavy metals, especially in relation to the compost. The two cultivars responded differently to the treatments, in terms of growth and tissue characteristics, compared with the control. GMF resulted in a higher availability of essential nutrients, Al, Na and heavy metals. In the GMF treatment, the root-to-shoot ratio was 1.6 times higher than both the control and CMP treatment in ‘The Fairy’ rose. Chlorophyll content was on average -17.12 % in GMF, compared with the control and CMP treatment, in ‘Knock Out®’ rose. CMP induced biomass accumulation, but with unexpected effects on the specific leaf area.

Breeding Leucospermum hybrids for potted flowering plant production, landscape uses and for cutflower production in the tropics; genetic factors contributing to plant architecture

Breeding <i>Leucospermum</i> hybrids for potted flowering plant production, landscape uses and for cutflower production in the tropics; genetic factors contributing to plant architecture

Pest categorisation of Ripersiella hibisci.

The EFSA Panel on Plant Health performed a pest categorisation of Ripersiella hibisci (Hemiptera: Rhizoecidae) for the EU. R. hibisci occurs in Japan, China and Taiwan and has spread to the USA: Florida, Hawaii and the territory of Puerto Rico. R. hibisci is a polyphagous mealybug recorded feeding on roots of monocotyledonous and dicotyledonous plants. Root damage reduces nutrient and water uptake, retards plant growth and may cause leaves to wilt or discolour, heavily infested plants can die. Literature most commonly refers to damage to greenhouse grown potted ornamentals such as Cuphea, Hibiscus, Pelargonium and Phoenix. All life stages occur in the soil and host plants for planting with growing media provide a pathway for eggs, nymphs and adults. Multiple overlapping generations occur in greenhouses each year. R. hibisci is listed in Annex IIA of EU Regulation 2016/2031, appearing with the synonym Rhizoecus hibisci. All plants for planting from third countries are regulated. The import of soil or growing medium attached to plants for planting from third countries (other than Switzerland) is prohibited and therefore reduces the likelihood, but does not prevent entry of R. hibisci, as individuals may remain attached to the roots. There have been interceptions of R. hibisci in the EU, usually on artificially dwarfed plants, i.e. bonsai/penjing. Findings in EU greenhouses have been eradicated. R. hibisci would be able to establish in the EU, greenhouse potted plant production would be most affected. Phytosanitary measures are available to lower the likelihood of introduction. R. hibisci satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest. R. hibisci does not meet the criterion of occurring in the EU for it to be regarded as a potential Union regulated non‐quarantine pest.

SUSTAINABLE, CIRCULAR AND INNOVATIVE VALUE CHAINS USING GROWING SUBSTRATA ALTERNATIVE TO PEAT FOR THE CULTIVATION OF NUTRACEUTICAL SPECIES

The modern agricultural system is wasteful, with Europe generating some 700 million tonnes of agricultural and food waste each year. In the context of the agri-food chain, the ‘circular economy’ aims to reduce waste while also making best use of the ‘wastes’ produced by using economically viable processes and procedures to increase their value. In this paper we will try to frame the key issues associated with food waste into the emerging bioeconomy and circular-economic mode, suggesting that these three concepts are intertwined, and considering them unitarily might provide win-win solutions that minimize wastage, promote income growth and job creation, and prompt sustainable local development. In terms of performance and economic considerations, peat is in many ways an ideal constituent of soilless growing media. Peat has become the material of choice throughout plant production systems from propagation to saleable ‘finished plant’ material. However, the extraction of peat has well documented negative impacts on the environment; arguably the most important of these is the release of stable, sequestered carbon into the active carbon cycle, thereby exacerbating climate change. During the last 20 years, peat extraction has come under increasing scrutiny throughout Europe and particularly in the UK. This has generated an abundance of studies examining a diverse range of alternative materials (as compost, vermicompost, digestate, biochar). In the selection of new materials, environmental considerations have become as important as performance and economic cost. In this context there has been a justifiable emphasis on organic materials derived from agricultural, industrial and municipal waste streams. For future urban sustainability it is necessary to develop integrated processes, which can be part of a circular bio-economy. However the challenge still remains of simultaneously recycling the nutrients from the waste. The greenhouse horticulture applied to nutraceutical species is the ideal sector for improving the conversion rate of organic waste into food and health friendly products. On farm composting/vermicomposting/pyrolysis/anaerobic digestion and the use of the end-product to the partial substitution of peat in nursery activity allows reducing the environmental and economic costs in the production of potted plants.

Potted plant production of Leptospermum scoparium hybrids as affected by temperature, photoperiod, irradiance and fertiliser treatments

ABSTRACTLeptospermum scoparium ‘Kea’, ‘Kiwi’ and ‘Ruru’ were evaluated for production as potted plants. Following environmental effects were investigated; (a) Temperatures regimes for 40 days each for two periods; (b) Photoperiods for 25 and 50 days; (c) Combined effects of temperature and duration; (d) Combined effects of temperature and irradiance and (e) Combined effects of day length, irradiance and fertilisers treatments. Floral initiation was completed following 25 days of a 9–12 h short-day (SD) photoperiod at 15/13°C (day/night). Floral development was accelerated at 20/18°C during the first period, and at 25/23°C during the second period. Flower buds were initiated at 14–15/11–14°C and SD. Although the irradiance and nutrition effects were less prominent than temperature and photoperiod, 25/22°C, high irradiance discharge (HID), and 100 ppm of nitrogen from a liquid fertiliser (LF) with 0.5 g of slow-release fertiliser (SRF) are suggested optimum for flowering. The following conditions are recommended for production of compact plants with maximum number of flowers year round starting from small propagules of three L. scoparium hybrids: 9–12 h SD under 15/13°C (day/night) for 25 days, at 20/17°C for 30 days, under 42 W m−2 HID, and fertilisation of 100 ppm N in LF with 0.5 g of SRF.

The effects of simulated vibration stress on plant height and some physical and mechanical properties of Coleus blumei Benth.

Non-chemical control of plant growth is an important goal for the production of ornamental pot plants. In the present study the effects of simulated vibration on plant height and some physical and mechanical properties of Coleus stem were investigated. The study was conducted as a factorial experiment based on a completely randomized design with three replications. Vibration stresses were performed using a laboratory vibration simulator and the effects of vibration parameters such as frequency and duration on the stem characteristics of Coleus plants were examined. Vibration frequency included three levels of 7.5, 10 and 12.5 Hz and vibration duration included three levels of 0 (control), 5 and 10 min. Based on the obtained results, vibration stress caused significant decrease in the height and surface area of the stems. Vibration frequency of 12.5 Hz with 10 min duration caused 31% decrease in plant height in comparing to the control samples. Mechanical properties of stems including modulus of elasticity, bending force, and bending stress were reduced by increasing vibration frequency and duration when compared to the control samples. In conclusion, the results of the current study indicated that vibration stress on Coleus decreased plant height while increased the elasticity and resistance to the fracture caused by mechanical forces of the stem.

Linking biochar properties to biomass of basil, lettuce and pansy cultivated in growing media

The use of biochar as an additive for growing media for the production of potted plants requires a sound knowledge of how its properties impact plant biomass production. This study aims at linking physical and chemical properties of biochar with horticultural crop biomass. For this purpose, we incorporated six different biochars into growing medium and grew basil (Ocimum basilicum L.), lettuce (Lactuca sativa L. var. crispa) and pansy (Viola wittrockiana Gams.) for one month in greenhouse conditions. We found that physical and chemical properties of biochars had a significant impact on plant growth. Biochars with low density and high porosity promoted the biomass of basil and lettuce. While nutrient concentration in biochars had no impact on plant growth, lettuce and pansy biomasses decreased with increasing biochar pH and basil biomass decreased with increasing biochar electrical conductivity. By identifying which biochar properties influence plant biomass, our study allows selection of the biochars which are the best suited for incorporation into growing media.

Greenhouse gas emissions from different plant production system in China

Abstract For the environmental efficiency assessment of the plant nursery production system, the total CO2 eq emissions of 18 nurseries in China was calculated using the LCA “from cradle to gate” approach. The analysis revealed that the GHG emissions of potted plant production were higher than those of field-grown nurseries. The CO2 eq emissions were variable between 0.31 and 2.19 Mg ha−1 year−1 for field-grown nurseries, while the lowest and the highest emissions were 4.09 and 6.06 Mg ha−1 year−1, respectively, for potted plant nurseries. In 2015, the total CO2 eq emissions of the nursery production industry in China were approximately 1.59 Mt, which consisted of 1.07 Mt from field-grown nurseries and 0.52 Mt from pot-grown plant nurseries. In China, nursery production industry carbon emissions were 0.19% of the national agriculture emissions. The comparison showed that the GHG emissions of the nursery plant system have significant differences depending on region, production method, plant species and economic development level.

Use of black soldier fly (Hermetia illucens (L.), Diptera: Stratiomyidae) larvae processing residue in peat-based growing media

The Black Soldier Fly (Hermetia illucens (L.), Diptera: Stratiomyidae) is an insect whose larvae thrive on agro-industrial by-products. This study reports the first use of black soldier fly larvae processing residue (BSPR) as an innovative ingredient for growing media. BSPR was characterized and evaluated to partially replace commercial peat (CP) in the production of potted plants. Chemical and microbiological analysis showed the suitability of BSPR for soilless production. Hence, six growing media mixtures (CP 100% + slow acting synthetic solid fertilizer, CP 90% + BSPR 10%, CP 80% + BSPR 20%, CP 70% + BSPR 30%, CP 60% + BSPR 40% and CP 100% without fertilizer) were assessed for the production of baby leaf lettuce, basil and tomato potted plants. Using BSPR in a proportion up to 20%, all investigated crops showed values significantly greater than or comparable to those obtained using CP 100% + slow acting synthetic solid fertilizer. In general, BSPR used in a proportion up to 20% increased the crop growth of baby leaf lettuce, basil and tomato, recording a high total dry weight (+31%, compared to the total average) and the measured leaf parameters (+39% of leaf area, +14% of leaf number), without showing abiotic stresses. This study indicates that BSPR used in a proportion up to 20% might be a valid approach for soilless production of potted baby leaf lettuce, basil and tomato plants.