Finishing Bedding Plants: A Comparison of an Unheated High Tunnel versus a Heated Greenhouse in Two Geographic Locations

Energy accounts for one of the largest costs in commercial greenhouse (GH) production of annual bedding plants. Therefore, many bedding plant producers are searching for energy efficient production methods. Our objectives were to quantify the impact of growing annual bedding plants in an unheated high tunnel (HT) compared with a traditional heated GH environment at two northern latitudes. Ten popular bedding plants [angelonia (Angelonia angustifolia), vinca (Catharanthus roseus), celosia (Celosia argentea), dianthus (Dianthus chinensis), geranium (Pelargonium ×hortorum), petunia (Petunia ×hybrida), french marigold (Tagetes patula), viola (Viola ×cornuta), snapdragon (Antirrhinum majus), and osteospermum (Osteospermum ecklonis)] were grown both in an unheated HT and a glass-glazed GH with an 18 °C temperature set point beginning on 1 Apr. 2011 at both Cornell University (Ithaca, NY) and Purdue University (West Lafayette, IN). Although seven of the species exhibited a delay in flowering in the HT as compared with the heated GH, there were no differences in days to flower (DTF) for geranium, osteospermum, and viola grown at Cornell and viola at Purdue. The remaining species exhibited delays in flowering in the HT environment, which varied based on species. At Purdue, several species were lost because of a cold temperature event necessitating a second planting. For the second planting, osteospermum was the only species grown that flowered significantly later in the HT; 7 days later than the GH-grown plants. Production of cold-tolerant annuals in unheated or minimally heated HTs appears to be a viable alternative for commercial producers aiming to reduce energy costs.

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High Tunnel and Outdoor Production of Containerized Annual Bedding Plants in the Midwestern United States

HortTechnology ◽

10.21273/horttech03454-16 ◽

2016 ◽

Vol 26 (5) ◽

pp. 651-656

Author(s):

Madeline W. Olberg ◽

Roberto G. Lopez

Keyword(s):

Plant Species ◽

Plant Production ◽

Stem Length ◽

High Quality ◽

Branch Number ◽

High Tunnel ◽

Bedding Plants ◽

Acclimation Period ◽

Bedding Plant ◽

Cold Tolerant

Due to the high cost associated with constructing and operating a greenhouse, many growers have begun using alternative, low-input methods for bedding plant production, such as unheated high tunnel and outdoor production. Previous research indicates that bedding plant production in unheated high tunnels may be suitable for cold-tolerant species, but flowering is delayed compared with greenhouse production. To our knowledge, there has been no published research on the effects of outdoor production on bedding plant species. The objectives of this study were therefore to 1) compare the growth and development of 10 cold-tolerant and intermediate annual bedding plant species grown in an unheated high tunnel or in an unprotected outdoor growing area, 2) evaluate the effect of a 1-week acclimation period in the high tunnel before outdoor production, and 3) quantify the effectiveness of these production methods for producing high-quality bedding crops. Seedlings of ‘Antigua Orange’ african marigold (Tagetes erecta), ‘Hot Cakes White’ stock (Matthiola incana), and ‘Lilac Flame’ primula (Primula acaulis), and rooted cuttings of ‘Aloha Kona Hot Pink’ calibrachoa (Calibrachoa ×hybrida), ‘Royal Lavender’ regal geranium (Pelargonium ×domesticum), ‘Bella Oceano’ lobelia (Lobelia erinus), ‘Potunia Plus Red’ petunia (Petunia ×hybrida), ‘Phloxy Lady Purple’ phlox (Phlox maculata), ‘Summertime Pink Charme’ osteospermum (Osteospermum ecklonis), and ‘Empress Purple’ verbena (Verbena ×hybrida) were transplanted on 13 Apr. 2015 (week 16) into an unheated high tunnel or an outdoor growing area, or into an unheated high tunnel for a 1-week acclimation period before being moved outdoors. Average mean daily air temperature was 2.3 °C lower outdoors compared with inside the high tunnel, whereas average daily light integral (DLI) increased by 11.7 mol·m−2·d−1. All plants were delayed when grown outdoors compared with in the high tunnel, and all marigolds grown outdoors died in April when outdoor air temperatures dropped below −4 °C. When plants were acclimated for a 1-week period before outdoor production, all species, with the exception of regal geranium, were delayed by less than 1 week compared with those grown in the high tunnel. Stem length of all species grown outdoors was reduced or similar to those in the high tunnel, whereas biomass accumulation and branch number was unaffected or increased for most species. Overall, high-quality bedding plants could be grown outdoors, although development may be delayed compared with high tunnel production. Growers must be aware of the risk of crop loss due to extreme temperatures and plan for delays when growing annual bedding plant crops outdoors.

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High Tunnel versus Climate-controlled Greenhouse: Transplant Time and Production Environment Impact Growth and Morphology of Cold-tolerant Bedding Plants

HortScience ◽

10.21273/hortsci.50.6.830 ◽

2015 ◽

Vol 50 (6) ◽

pp. 830-838 ◽

Cited By ~ 1

Author(s):

Joshua R. Gerovac ◽

Roberto G. Lopez ◽

Neil S. Mattson

Keyword(s):

Plant Production ◽

Late Winter ◽

Production Environment ◽

Environment Impact ◽

Open Flower ◽

Bedding Plants ◽

Northern Latitude ◽

Northern Latitudes ◽

Bedding Plant ◽

Cold Tolerant

Commercial bedding plant production in northern latitudes often begins in late winter and continues through spring, when average outdoor temperatures require growers to actively heat their greenhouses (GHs). High tunnels (HTs) offer energy savings as they are passively heated and cooled structures that have a low initial cost. As a result, they have been used in northern latitudes to advance and extend the growing season and improve the quality of high-value horticultural crops. However, there is limited published information on growing bedding plants in HTs in northern latitudes. Our objectives were to quantify the effects of transplant date in an HT with or without a rowcover (RC) compared with a traditional heated GH on the growth and morphology of three cold-tolerant bedding plant species at two northern latitude locations, Purdue University (Purdue) and Cornell University (Cornell). Seedlings of snapdragon (Antirrhinum majus L. ‘Liberty Classic Yellow’), dianthus (Dianthus chinensis L. ‘Telstar Crimson’), and petunia (Petunia ×hybrida Vilm.-Andr. ‘Wave Pink’) were transplanted on weeks 13, 14, and 15 in 2012 (Purdue) and 2013 (both locations) and moved to either a glass-glazed GH or an HT without (HT) or with a rowcover (HT+RC). Several quality measurements increased when plants were grown in the HT compared with those grown in the GH. Dianthus and petunia transplanted at Purdue during week 13 in the HT and HT+RC were 33% and 47% shorter and had 51% and 31% more visible buds, respectively, compared with those grown in the GH. Similarly, petunia transplanted at Cornell during week 13 in the HT and HT+RC were 45% and 43% shorter, respectively, than their GH counterparts. The shoot dry mass of dianthus and snapdragon at Purdue was significantly higher when grown in the HT compared with the GH, regardless of transplant week or the use of RC likely because of increased daily light integral (DLI) in the HT environment. There was about a 1-week delay from transplant to first open flower for week 13 dianthus (at Purdue) and petunia (at both locations) when finished in the HT or HT+RC vs. their GH counterparts. Such a delay would be acceptable to growers who want to reduce the use of chemical growth regulators and heating costs. However, at both locations snapdragon transplanted on week 13 to the HT or HT+RC environments were delayed by 22 to 26 days compared with the GH. A delay of over 3 weeks could interfere with a grower’s production schedule, possibly making this crop unsuitable for production in northern latitude HTs.

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Anion Species in Fertilizers Affect Growth and Development in Bedding Plants

HortScience ◽

10.21273/hortsci.39.4.776e ◽

2004 ◽

Vol 39 (4) ◽

pp. 776E-777

Author(s):

Dharmalingam S. Pitchay* ◽

Jonathan M. Frantz ◽

James C. Locke

Keyword(s):

Growth And Development ◽

Plant Production ◽

Rhizosphere Ph ◽

Growth Responses ◽

Inorganic Fertilizers ◽

Additional Tool ◽

Bedding Plants ◽

Bedding Plant ◽

The Impact ◽

Anion Species

Currently, formulation of inorganic fertilizers is based on cation amounts such as NH4, K, Mg, Ca, Fe, MN Cu, and Zn, whereas anion species and amounts are viewed, with few exceptions, as necessary fillers. The delivery of cations in the nutrient solution is associated with an anion such as Cl, SO4, NO3, PO4 or CO3. These anions at higher concentrations can result in different growth responses by altering the rhizosphere pH, soluble salts, and influencing the uptake of both cations and anions. The impact of these anions has not been extensively studied in the formulation of inorganic fertilizers. Several experiments assessed the effect of SO4 and Cl on root and shoot growth and development of bedding plants represented by petunia, impatiens, and vinca. In all treatments, plant height, shoot and root dry weight, and flower number decreased with an increase in Cl concentration. Root morphology was marked by fewer total roots and shorter primary and secondary roots when grown with Cl anions compared to the plants grown with SO4 anions. This indicates that anions have a larger role in determining optimum fertilizer formulation than previously believed. This information provides an additional tool in formulating fertilizers for greenhouse bedding plant production.

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Influence of Substrate and Fertilizer Analysis and Rate on Growth and Quality of Five Species of Bedding Plants

HortTechnology ◽

10.21273/horttech.11.3.434 ◽

2001 ◽

Vol 11 (3) ◽

pp. 434-437

Author(s):

Timothy K. Broschat ◽

Kimberly A. Moore

Keyword(s):

Fertilization Rate ◽

Pine Bark ◽

Tagetes Patula ◽

Bedding Plants ◽

Salvia Splendens ◽

Bedding Plant ◽

Influence Of Substrate ◽

Highly Correlated ◽

Controlled Release Fertilizers

Salvia (Salvia splendens) `Red Vista' or `Purple Vista,' french marigold (Tagetes patula) `Little Hero Orange,' bell pepper (Capsicum annuum) `Better Bell,' impatiens (Impatiens wallerana) `Accent White,' and wax begonia (Begonia ×semperflorens-cultorum) `Cocktail Vodka' were grown in 0.95-L (1-qt) containers using a 5 pine bark: 4 sedge peat: 1 sand substrate (Expts. 1 and 2) or Pro Mix BX (Expt. 2 only). They were fertilized weekly with 50 mL (1.7 fl oz) of a solution containing 100, 200, or 300 mg·L-1 (ppm) of nitrogen derived from 15N-6.5P-12.5K (1N-1P2O5-1K2O ratio) or 21N-3P-11.7K (3N-1P2O5-2K2O ratio) uncoated prills used in the manufacture of controlled-release fertilizers. Plants grown with Pro Mix BX were generally larger and produced more flowers or fruit than those grown with the pine bark mix. With few exceptions, plant color, root and shoot dry weights, and number of flowers or fruit were highly correlated with fertilization rate, but not with prill type. There appears to be little reason for using the more expensive 1-1-1 ratio prills, since they generally did not improve plant quality and may increase phosphorous runoff from bedding plant nurseries.

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Improving Bedding Plant Quality and Stress Resistance with Low Phosphorus

HortTechnology ◽

10.21273/horttech.8.4.575 ◽

1998 ◽

Vol 8 (4) ◽

pp. 575-579 ◽

Cited By ~ 6

Author(s):

Kristian Borch ◽

Kathleen M. Brown ◽

Jonathan P. Lynch

Keyword(s):

Leaf Area ◽

Root Distribution ◽

Small Volume ◽

Plant Quality ◽

Tagetes Patula ◽

Bedding Plants ◽

Bedding Plant ◽

Low Phosphorus ◽

P Fertilizer ◽

P Leaching

Bedding plants are frequently exposed to water stress during the postproduction period, resulting in reduced quality. We demonstrated that alumina-buffered P fertilizer (Al-P) provides adequate but much lower P concentrations than conventionally used in soilless mixes. When impatiens (Impatiens wallerana Hook. f. `Impulse Orange') and marigold (Tagetes patula L. `Janie Tangerine') plants were grown with reduced phosphorus using Al-P, P leaching was greatly reduced and plant quality was improved. Diameter of impatiens plants and leaf area of plants of both species were reduced by Al-P. Marigold plants grown with Al-P had more flowers and fewer wilted flowers. Flower wilting was also reduced for impatiens plants grown with Al-P. In marigold plants, roots were confined to a small volume beneath the drip tube in control plants, while roots of Al-P plants were well distributed through the medium. There was no obvious difference in impatiens root distribution. When plants at the marketing stage were exposed to drought, the Al-P plants of both species wilted more slowly than the conventionally fertilized controls. The reduced leaf area in both species and the improved root distribution of marigold may account for the improvement in drought tolerance of the Al-P plants.

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Short-term Temperature Change Affects the Carbon Exchange Characteristics and Growth of Four Bedding Plant Species

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.128.1.0100 ◽

2003 ◽

Vol 128 (1) ◽

pp. 100-106 ◽

Cited By ~ 13

Author(s):

Marc W. van Iersel

Keyword(s):

Growth Rate ◽

Dark Respiration ◽

Net Photosynthesis ◽

Tagetes Patula ◽

Short Term ◽

Response Curves ◽

Gross Photosynthesis ◽

Bedding Plants ◽

Bedding Plant ◽

Wide Range

Bedding plants are exposed to a wide range of environmental conditions, both during production and in the landscape. This research compared the effect of short-term temperature changes on the CO2 exchange rates of four popular bedding plants species. Net photosynthesis (Pnet) and dark respiration (Rdark) of geranium (Pelargonium ×hortorum L.H. Bail.), marigold (Tagetes patula L.), pansy (Viola ×wittrockiana Gams.), and petunia (Petunia ×hybrida Hort. Vilm.-Andr.) were measured at temperatures ranging from 8 to 38 °C (for Pnet) and 6 to 36 °C (for Rdark). Net photosynthesis of all species was maximal at 14 to 15 °C, while Rdark of all four species increased exponentially with increasing temperature. Gross photosynthesis (Pgross) was estimated as the sum of Pnet and Rdark, and was greater for petunia than for the other three species. Gross photosynthesis was less sensitive to temperature than either Pnet or Rdark, suggesting that temperature effects on Pnet were caused mainly by increased respiration at higher temperatures. Gas exchange-temperature response curves were not useful in determining the heat tolerance of these species. There were significant differences among species in the estimated Rdark at 0 °C and the Q10 for Rdark. Differences in the Q10 for Rdark were related to growth rate and plant size. Large plants had a greater Q10 for Rdark, apparently because these plants had a higher ratio of maintenance to growth respiration than small plants. The Q10 of the maintenance respiration coefficient was estimated from the correlation between the Q10 and relative growth rate, and was found to be 2.5 to 2.6.

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Growth of Ornamental Plants in Compacted Soils in Relation to Root Growth under Low Oxygen and High Atmospheric Pressure

HortScience ◽

10.21273/hortsci.33.3.479d ◽

1998 ◽

Vol 33 (3) ◽

pp. 479d-479

Author(s):

Michael Knee ◽

Ruth Brake

Keyword(s):

Atmospheric Pressure ◽

Root Elongation ◽

Native Plants ◽

Tagetes Patula ◽

Low Oxygen ◽

Compacted Soils ◽

Bedding Plants ◽

Four Levels ◽

Physical Resistance ◽

High Atmospheric Pressure

In urban situations, particularly after construction, herbaceous ornamentals may be planted into soils that are compacted or have poor structure so that plant roots may encounter poor aeration or physical resistance. Low oxygen concentrations may be the most important aspect of poor aeration and are readily reproduced in the laboratory. High atmospheric pressure might be used to screen for the ability to grow against physical resistance. We tested the suggestion that “native” plants would grow better in compacted soils than typical bedding plants and for differences in tolerance to low oxygen or high pressure. Plants were grown from seed in the greenhouse at four levels of compaction in peat-based medium and in field soil. Shoot dry weights of the native plants Asclepias tuberosa, Echinacea purpurea, and Schizachyrium scoparius, were less affected by growth in compacted soil or peat medium than those of the bedding plants, Antirrhinum majus, Gypsophila elegans, Impatiens balsamina, Tagetes patula and Zinnia elegans. The oxygen content of media declined with compaction to a minimum of 10 kPa. Half maximal root elongation was observed at 1 to 3 kPa oxygen for most species without any separation between the groups. A presure of 1100 kPa reduced root elongation of the bedding plants by 50 to 70% but only 5 to 20% for the native plants.

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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.

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Impact of Shade and Fogging on High Tunnel Production and Mineral Content of Organically Grown Lettuce, Basil, and Arugula in Georgia

Agriculture ◽

10.3390/agriculture11070625 ◽

2021 ◽

Vol 11 (7) ◽

pp. 625

Author(s):

Savanah Laur ◽

Andre Luiz Biscaia Ribeiro da Silva ◽

Juan Carlos Díaz-Pérez ◽

Timothy Coolong

Keyword(s):

Mineral Content ◽

Planting Date ◽

High Tunnel ◽

Lactuca Sativa L ◽

Air Temperatures ◽

Shade Cloth ◽

High Tunnels ◽

Soil Temperatures ◽

Organically Grown ◽

The Impact

This study evaluated the impact of shade cloth and fogging systems on the microclimate at the plant canopy level and yield of basil (Oscimum basilicum L.), arugula (Eruca vesicaria subsp. Sativa L.), and lettuce (Lactuca sativa L.) planted in mid-September and early October in high tunnels. Fogging systems were installed at canopy level in plots within shaded (30%) and non-shaded high tunnels. Average air temperatures in the shaded high tunnels were 0.9 °C lower than non-shaded high tunnels during the day. Shade cloth significantly reduced soil temperatures during the day and night periods by 1.5 °C and 1.3 °C, respectively, compared to non-shaded treatments. Fogging systems did not have an impact on air temperature, soil temperature, or relative humidity, but did increase canopy leaf wetness. Shade and fogging did not impact the yield of any of the crops grown. Yield was impacted by planting date, with earlier planting result in higher yields of lettuce and basil. Yields for arugula were greater during the second planting date than the first. Planting date and shade cloth interacted to affect the concentrations of macronutrients.

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The influence of advance speed on overburden movement characteristics in longwall coal mining: insight from theoretical analysis and physical simulation

Journal of Geophysics and Engineering ◽

10.1093/jge/gxab005 ◽

2021 ◽

Vol 18 (1) ◽

pp. 163-176

Author(s):

Penghua Han ◽

Cun Zhang ◽

Zhaopeng Ren ◽

Xiang He ◽

Sheng Jia

Keyword(s):

Physical Simulation ◽

Impact Load ◽

Main Roof ◽

Longwall Face ◽

Mine Safety ◽

Efficient Production ◽

Time Space ◽

Mining Pressure ◽

The Impact ◽

Advance Speed

Abstract The advance speed of a longwall face is an essential factor affecting the mining pressure and overburden movement, and an effective approach for choosing a reasonable advance speed to realise coal mine safety and efficient production is needed. To clarify the influence of advance speed on the overburden movement law of a fully mechanised longwall face, a time-space subsidence model of overburden movement is established by the continuous medium analysis method. The movement law of overburden in terms of the advance speed is obtained, and mining stress characteristics at different advance speeds are reasonably explained. The theoretical results of this model are further verified by a physical simulation experiment. The results support the following conclusions. (i) With increasing advance speed of the longwall face, the first (periodic) rupture interval of the main roof and the key stratum increase, while the subsidence of the roof, the fracture angle and the rotation angle of the roof decrease. (ii) With increasing advance speed, the roof displacement range decreases gradually, and the influence range of the advance speed on the roof subsidence is 75 m behind the longwall face. (iii) An increase in the advance speed of the longwall face from 4.89 to 15.23 m/d (daily advancing of the longwall face) results in a 3.28% increase in the impact load caused by the sliding instability of the fractured rock of the main roof and a 5.79% decrease in the additional load caused by the rotation of the main roof, ultimately resulting in a 9.63% increase in the average dynamic load coefficient of the support. The roof subsidence model based on advance speed is proposed to provide theoretical support for rational mining design and mining-pressure-control early warning for a fully mechanised longwall face.

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