The Combined Conditions of Photoperiod, Light Intensity, and Air Temperature Control the Growth and Development of Tomato and Red Pepper Seedlings in a Closed Transplant Production System

Understanding environmental factors is essential to maximizing the biomass production of plants. There have been many studies on the effects of the photosynthetic photon flux (PPF), photoperiod and air temperature as separate factors affecting plants, including under a closed transplant production system (CTPS). However, few studies have investigated the combined effects of these factors on plant growth. Germinated tomato and red pepper seedlings were transferred to three different photoperiods with five different photosynthetic photon fluxes (PPFs) at an air temperature of 25/20 °C to investigate plant growth under a different daily light integral (DLI). Three different air temperatures, 23/20, 25/20, and 27/20 °C (photo/dark periods), with five different PPFs were used to examine plant growth under different DIFs (difference between the day and night temperature). Increasing the DLI from 4.32 to 21.60 mol·m−2·d−1, either by increasing the photoperiod or PPF, improved the growth of seedlings in both cultivars. However, when comparing treatments that provided the same DLI, tomato seedlings had s significantly higher growth when grown under longer photoperiods and s lower PPF. Even in higher DLI conditions, reduced growth due to higher PPF indicated that excessive light energy was a limiting factor. At 23 and 25 °C, tomato seedlings showed similar correlation curves between growth and PPF. However, at the higher temperature of 27 °C, while the slope of the curve at low PPFs was similar to that of the curves at lower temperatures, the slope at high PPFs was flatter. On the other hand, red pepper seedlings displayed the same correlation curve between growth and PPF at all tested temperatures, and red pepper plants accumulated more dry weight even at higher temperatures. These results suggested that the combination effect was more useful to observe these overall tendencies, especially in reacting to a second factor. This will provide us with more information and a deeper understanding of plant characteristics and how they will behave under changing environments.

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Potential Use of a 24-Hour Photoperiod (Continuous Light) with Alternating Air Temperature for Production of Tomato Plug Transplants in a Closed System

HortScience ◽

10.21273/hortsci.40.2.374 ◽

2005 ◽

Vol 40 (2) ◽

pp. 374-377 ◽

Cited By ~ 14

Author(s):

Katsumi Ohyama ◽

Koji Manabe ◽

Yoshitaka Omura ◽

Toyoki Kozai ◽

Chieri Kubota

Keyword(s):

Air Temperature ◽

Closed System ◽

Energy Use ◽

Electric Energy ◽

Continuous Light ◽

Dry Weight ◽

Photon Flux ◽

Air Temperatures ◽

Use Efficiency ◽

Potential Use

To evaluate the potential use of a 24-hour photoperiod for transplant production in a closed system, tomato (Lycopersicon esculentum Mill.) plug transplants were grown for 17 days either under a 24-hour photoperiod with a photosynthetic photon flux (PPF) of 200 μmol·m-2·s-1 or under a 16-hour photoperiod with a PPF of 300 μmol·m-2·s-1, resulting in the same daily integrated PPF (17.3 mol·m-2). Air temperatures were alternated between 28 °C during the first 16 hours and 16 °C for the subsequent 8 hours of each day. Fresh weight, dry weight and leaf area were 41%, 25%, and 64% greater, respectively, under the 24-hour photoperiod than under the 16-hour photoperiod. Physiological disorders (e.g., chlorosis and/or necrosis) were not observed under the 24-hour photoperiod, probably due to the alternating air temperature. Floral development of plants originating from both treatments did not differ significantly. Electric energy use efficiency of the closed system was 9% greater under the 24-hour photoperiod than under the 16-hour photoperiod. These results suggest that using a 24-hour photoperiod with relatively low PPF can reduce both initial and operational costs for transplant production in a closed system due to the reduction in the number of lamps.

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Effects of Air Temperature Regimes on Physiological Disorders and Floral Development of Tomato Seedlings Grown under Continuous Light

HortScience ◽

10.21273/hortsci.40.5.1304 ◽

2005 ◽

Vol 40 (5) ◽

pp. 1304-1306 ◽

Cited By ~ 9

Author(s):

Katsumi Ohyama ◽

Yoshitaka Omura ◽

Toyoki Kozai

Keyword(s):

Air Temperature ◽

Floral Development ◽

Continuous Light ◽

Photon Flux ◽

Photosynthetic Photon Flux ◽

Tomato Seedlings ◽

Physiological Disorders ◽

Air Temperatures ◽

Temperature Regimes ◽

Leaf Chlorosis

Providing continuous light (24-h photoperiod) at a relatively low photosynthetic photon flux (PPF) is one possible way to reduce both initial and operational costs for lighting and cooling during transplant production with an artificial light. However, physiological disorders (i.e., chlorosis and necrosis) are often observed in several species under continuous light with a constant temperature. The objective of this study was to find an effective air-temperature regime under the continuous light to avoid such physiological disorders, and simultaneously enhance floral development, using tomato [Lycopersicon esculentum Mill.] as a model. The seedlings with fully expanded cotyledons were grown for 15 d at a PPF of 150 μmol·m–2·s–1, a relative humidity of 70%, and a CO2 concentration of about 380 μmol·mol–1 (atmospheric standard). Leaf chlorosis was observed when the air temperature was constant regardless of average air temperature (16, 22,or 28 °C). Neither leaf chlorosis nor necrosis was observed when the air temperatures were alternated [periods of high (28 °C) and low (16 °C) air temperatures of 16/8, 12/12, and 8/16 h·d–1]. Faster floral development was observed in the seedlings grown at lower average air temperatures. These results indicated that physiological disorders of tomato seedlings grown under continuous light could be avoided, and at the same time floral development could be enhanced, by lowering the average air temperature through modification of the periods of high and low air temperatures.

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INTERACTIONS ENTRE LES TEMPERATURES RACINAIRES ET NOCTURNES SUR LE DEVELOPPEMENT FOLIAIRE ET LA CAPACITE PHOTOSYNTHETIQUE DE PLANTS DE TOMATE CV. VENDOR

Canadian Journal of Plant Science ◽

10.4141/cjps85-025 ◽

1985 ◽

Vol 65 (1) ◽

pp. 185-192 ◽

Cited By ~ 1

Author(s):

ANDRÉ GOSSELIN ◽

MARC-J. TRUDEL

Keyword(s):

Air Temperature ◽

Leaf Growth ◽

Dry Weight ◽

Negative Effects ◽

Root Temperature ◽

Tomato Plants ◽

Air Temperatures ◽

Plant Photosynthesis ◽

Leaf Dry Weight ◽

Capacité Photosynthétique

Six-week-old tomato plants (Lycopersicon esculentum Mill. ’Vendor’) were maintained at five root temperatures (12, 18, 24, 30 or 36 °C) and five night air temperatures (8, 12, 16, 20 or 24 °C) for a period of 4 wk. Increase in root temperature partly offset the negative effects of low night air temperature on leaf dry weight and leaf area. Our results showed that higher root temperatures (30 °C) are required at low night air temperature (8 °C) for optimum plant growth. Lower rates of plant photosynthesis at low root and/or night air temperatures resulted mainly from reduced leaf growth and expansion, but also from a decrease in the photosynthetic capacity of the leaves. Our results suggest combining split-night temperature and soil warming techniques to improve the productivity of tomato plants and to reduce greenhouse heating costs.Key words: Tomato substrate, temperature, photosynthesis, growth

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GROWTH RESPONSE OF SNAPDRAGON ANTIRRHINUM MAJUS TO NIGHT AIR TEMPERATURES AND ELEVATED ROOT-ZONE TEMPERATURES

HortScience ◽

10.21273/hortsci.25.9.1160b ◽

1990 ◽

Vol 25 (9) ◽

pp. 1160b-1160

Author(s):

Khin San Wai ◽

S.E. Newman

Keyword(s):

Air Temperature ◽

Growth Response ◽

Root Zone ◽

Dry Weight ◽

Antirrhinum Majus ◽

Root Zone Temperature ◽

Shoot Dry Weight ◽

Air Temperatures ◽

Diffusive Resistance ◽

Zone Temperature

The response of Antirrhinum majus (snapdragon) cultivars (`Tampicoi' and `Rainier White') to night air temperatures (10C and 20C) and elevated root-zone temperature (26C and ambient) was studied. Height of plants grown with a heated root-zone were greater, compared to unheated at both night temperatures for both cultivars. Shoot dry weight of `Tampico' plants was reduced by heated root-zone temperature at 20C night air temperature. Raceme length was greater with heated root-zone temperature compared to unheated at 10C night air temperature. Days to flower were shorter with heated compared to unheated root-zone at both night air temperatures for both cultivars. Stomatal diffusive resistance was greater on plants with unheated compared to heated root-zone temperature at 10C night air temperature for `Rainier White'.

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Pot-in-pot Production and Cyclic Irrigation Influences Growth and Evapotranspiration of `Okame' Cherry

HortScience ◽

10.21273/hortsci.32.3.546b ◽

1997 ◽

Vol 32 (3) ◽

pp. 546B-546 ◽

Cited By ~ 1

Author(s):

John M. Ruter

Keyword(s):

Plant Growth ◽

Production System ◽

Nitrate Nitrogen ◽

Dry Weight ◽

Stem Diameter ◽

Total Biomass ◽

Soluble Salts ◽

Root:Shoot Ratio ◽

Shoot Dry Weight ◽

Ground System

A study was conducted with Prunus × incamp `Okame' to evaluate the effects of a pot-in-pot production system compared to a conventional above-ground system and cyclic irrigation on plant growth and water loss. Plants were grown in #7 (26-L) containers with a 8:1 pinebark:sand (v/v) substrate. Cyclic irrigation provided the same total volume of water, but was applied one, three, or four times per day. Final plant height and stem diameter, shoot and root dry weight, total biomass, and root:shoot ratio were all increased for plants grown pot-in-pot compared to above-ground. Multiple irrigation cycles increased stem diameter, shoot dry weight, and total biomass, compared to a single irrigation application. Multiple irrigation cycles decreased the root:shoot ratio. Evapotranspiration was influenced by production system, irrigation, and date. Amount of water lost as leachate was influenced by irrigation and date. Cyclic irrigation resulted in a two-fold decrease in leachate volume. Soluble salts and nitrate-nitrogen in the leachate were influenced by an interaction between production system, irrigation, and date.

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Multilevel Factors Affecting the Route Decision for Foraging in the Generalist ant Pheidole oxyops

10.20944/preprints201804.0160.v1 ◽

2018 ◽

Author(s):

Diego Santana Assis ◽

Giovanni Abrami Rodrigues Camargo ◽

Fabio Santos do Nascimento

Keyword(s):

Air Temperature ◽

Residual Soil ◽

Nest Entrance ◽

Foraging Activity ◽

Plant Debris ◽

Factors Affecting ◽

Air Temperatures ◽

Soil Accumulation ◽

Daily Period ◽

Significant Factors

Pheidole oxyops Forel, 1908 is a generalist ant, which forages actively for plant debris to dead arthropods. In addition, its nest has an entrance that allows the ants gather resources passively by capturing falling preys into the nest. Our objective was to verify if different day periods, temperature and residual soil accumulation (ground pile in the side of nest entrance) could influence the patterns of foraging activity. Foraging activities were registered in the morning, afternoon and twilight. We measured direction and vector of trails, air temperature and humidity during foraging events. Our results showed that foraging routes are independent of residual soil accumulation and other nearby nests. However, air temperature and the time daily period are significant factors to foragers’ exits. Higher air temperatures influenced negatively the exits. In the period of the afternoon, the ants do not show any preference for routes, different from the morning and twilight. In addition, foraging activities were significantly more frequent during twilight period. Leaving the nest at twilight could allow ants foraging in an environment with less exposition to potential predators and competitors. Moreover, it may be also related to opportunism to hunt other nocturnal insects.

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(56) Transpiration and Photosynthesis of Grafted Watermelon Transplants as Affected by Environmental Factors during Graft Union Formation

HortScience ◽

10.21273/hortsci.40.4.996d ◽

2005 ◽

Vol 40 (4) ◽

pp. 996D-996

Author(s):

Sung Kyeom Kim ◽

Duk Jun Yu ◽

Ro Na Bae ◽

Hee Jae Lee ◽

Changhoo Chun

Keyword(s):

Environmental Factors ◽

Air Temperature ◽

Environmental Conditions ◽

Vapor Pressure Deficit ◽

Photon Flux ◽

Union Formation ◽

Graft Union ◽

Yield And Quality ◽

Air Temperatures ◽

Grafted Transplants

Grafted transplants are widely used for watermelon culture in Korea mainly to reduce the yield and quality losses caused by soil-borne diseases. It is normal practice to cure the grafted transplants under high relative humidity (RH) and low photosynthetic photon flux (PPF) conditions for a few days after grafting to prevent the wilting of the transplants. Transpiration rate (TR) and net photosynthetic rate (NPR), however, could be suppressed under those environmental conditions. In the present study, TR and NPR of the grafted watermelon transplants were compared during graft union formation under 18 environmental conditions combining two air temperatures (20 and 28 °C), three RHs (60%, 80%, and 100%), and three PPF s (0, 100, and 200 μmol·m-2·s-1). Percentages of graft union formation and survival were also evaluated. TR and NPR dramatically decreased just after grafting but slowly recovered 2 to 3 days after grafting at 28 °C. The recovery was clearer at higher PPF and lower RH. On the other hand, the recovery of TR and NPR was not observed in 7 days after grafting at 20 °C. Differences in TR and NPR affected by RH were nonsignificant. Percentage of graft union formation was 98% when air temperature, RH, and PPF were 28 °C, 100%, and 100 μmol·m-2·s-1, respectively, which was the highest among all the treatments. Percentage of survival was over 90% when air temperature was 28 °C and RH was higher than 80% (when vapor pressure deficit was lower than 0.76 kPa). In addition, higher PPF enhanced TR and NPR and promoted rooting and subsequent growth of grafted transplants. Results suggest that the acclimation process for grafted watermelon transplants can be omitted by properly manipulating environmental factors during graft union formation.

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Deep-Sea Actinobacteria Mitigate Salinity Stress in Tomato Seedlings and Their Biosafety Testing

Plants ◽

10.3390/plants10081687 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1687

Author(s):

Pharada Rangseekaew ◽

Adoración Barros-Rodríguez ◽

Wasu Pathom-aree ◽

Maximino Manzanera

Keyword(s):

Hydrogen Peroxide ◽

Plant Growth ◽

Salinity Stress ◽

Deep Sea ◽

Growth Parameters ◽

Dry Weight ◽

Growth Promoter ◽

Acetic Acid Production ◽

Tomato Seedlings

Soil salinity is an enormous problem affecting global agricultural productivity. Deep-sea actinobacteria are interesting due to their salt tolerance mechanisms. In the present study, we aim to determine the ability of deep-sea Dermacoccus (D. barathri MT2.1T and D. profundi MT2.2T) to promote tomato seedlings under 150 mM NaCl compared with the terrestrial strain D. nishinomiyaensis DSM20448T. All strains exhibit in vitro plant growth-promoting traits of indole-3-acetic acid production, phosphate solubilization, and siderophore production. Tomato seedlings inoculated with D. barathri MT2.1T showed higher growth parameters (shoot and root length, dry weight, and chlorophyll content) than non-inoculated tomato and the terrestrial strain under 150 mM NaCl. In addition, hydrogen peroxide (H2O2) in leaves of tomatoes inoculated with deep-sea Dermacoccus was lower than the control seedlings. This observation suggested that deep-sea Dermacoccus mitigated salt stress by reducing oxidative stress caused by hydrogen peroxide. D. barathri MT2.1T showed no harmful effects on Caenorhabditis elegans, Daphnia magna, Eisenia foetida, and Escherichia coli MC4100 in biosafety tests. This evidence suggests that D. barathri MT2.1T would be safe for use in the environment. Our results highlight the potential of deep-sea Dermacoccus as a plant growth promoter for tomatoes under salinity stress.

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Temperature Effects on Growth of Impatiens Plug Seedlings in Controlled Environments

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.117.2.209 ◽

1992 ◽

Vol 117 (2) ◽

pp. 209-215 ◽

Cited By ~ 3

Author(s):

David R. Dreesen ◽

Robert W. Langhans

Keyword(s):

Leaf Area ◽

Growth Period ◽

Dry Weight ◽

Photon Flux ◽

Initial Growth ◽

Growth Responses ◽

Shoot Height ◽

Seedling Age ◽

Shoot Dry Weight ◽

Air Temperatures

The objective of this study was to determine the dry weight, height, and leaf area growth responses of impatiens (Impatiens walerana Hook. f.) plug seedlings to air temperatures ranging from 18 to 29C. The conditions maintained in the controlled-environment growth rooms (CEGR) were ambient C02 levels, 24-h lighting, and photosynthetic photon flux (PPF) ranging from ≈215; to 335 μmol·m-2·s-1. Mean daily temperatures of the plug medium ranged from 19.6 to 27.7C. At the higher PPF level, shoot dry weight decreased at plug medium temperatures (PMT) > 25C; at lower PPF levels (<300 μmol·m-2·s-1), shoot dry weight continued to increase with PMT > 25C. The mean relative growth rate (MRGR) of shoot dry weight was positively correlated with PMT during the initial growth period (up to 14 days from sowing) and was negatively correlated thereafter. The maximum MRGR was predicted to occur at 11.7 days from sowing for a PMT of 19.6C, at 10.8 days for a PMT of 21.6C, and at 9.7 days for a PMT of 23.6C. Linear regression coefficients of shoot height as a function of PMT were substantially higher for seedlings grown at lower PPF than those for seedlings from the highest PPF level. Seedling leaf area consistently increased with increasing temperature. Net assimilation rate (NAR) decreased with increasing seedling age NAR increased with increasing PPF. A decrease in NAR was apparent at 29C relative to values at the lower temperatures. Leaf area ratio (LAR) declined with increasing seedling age and PPF; a quadratic relationship of LAR as a function of PMT indicates a minimum LAR at 22.5C. The seedlings grown at 29C were excessively tall, had thin succulent leaves, and were judged unacceptable for shipping and transplanting. Maximum quality indices (i.e., dry weight per height) were found at PMT of 24.3 to 25.OC for 10- to 14-day-old seedlings and at PMT of 23.0 to 24.OC for 16- to 20-day-old seedlings.

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An assessment of optimal air temperatures in pig houses by the quantification of behavioural and health-related problems

Animal Production ◽

10.1017/s0003356100004098 ◽

1989 ◽

Vol 48 (3) ◽

pp. 571-578 ◽

Cited By ~ 18

Author(s):

R Geers ◽

B. Dellaert ◽

V. Goedseels ◽

A. Hoogerbrugge ◽

E. Vranken ◽

...

Keyword(s):

Mortality Rate ◽

Air Temperature ◽

Stocking Density ◽

Live Weight ◽

Growth Period ◽

Factors Affecting ◽

Temperature Cycles ◽

Tail Biting ◽

Air Temperatures ◽

Summer Mortality

ABSTRACTAir temperatures were measured every 2 h in 12 growing-finishing pig houses. All houses were operated on the all-in, all-out, principle. Data were collected for two fattening periods in each house. Stocking density, feeding system, pig type, and the farmer's skill were standardized. Every 2 weeks, the houses were visited and live weight, mortality rate, the incidence of coughing and tail biting, and the extent of dirty lying areas were recorded.Air temperature limits could be isolated from the complex of factors affecting behavioural and health problems of pigs observed within these experiments. Sensitive periods within the growth period of the pigs seem to exist. At the onset of the fattening period (20 to 30 kg), pigs which have been transported from other farms need special care. During summer, mortality rate was lowered when the periodicity of the temperature cycles was lowered for 40- to 50-kg pigs, whereas for heavier pigs the mean maximal air temperature was important also. With respect to coughing, a statistically significant negative relation with the air temperature in the pig house was found for all weight classes, with interactions from the number of different temperature cycles within a 24-h period. In order to avoid dirty lying areas for 20- to 40-kg animals, air temperatures should be between 20 to 24°C, whereas for diarrhoea, animals of 40 to 50 kg were especially sensitive to the occurrence of low air temperatures. For minimizing tail biting, an optimal air temperature range of 20 to 22°C is suggested.

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