scholarly journals Numerical and Experimental Analyses on Root Zone Temperature in Aeroponic Cultivation Box

2020 ◽  
Vol 38 (4) ◽  
pp. 871-879
Author(s):  
Yahui Luo ◽  
Xiwen Yang ◽  
Pin Jiang
Keyword(s):  
Low Temperature ◽  
Energy Efficient ◽  
Cfd Simulation ◽  
Root Zone ◽  
Single Point ◽  
Maximum Error ◽  
Root Zone Temperature ◽  
Different Temperatures ◽  
Nutrient Solutions ◽  
Zone Temperature

Vegetable growth requires a relatively stable environment for the root zone. If the temperature in root zone environment is optimal, the aeroponic cultivation will be energy-efficient, and the aeroponic vegetables will grow well at high, normal, or low temperature. By computational fluid dynamics (CFD), this paper numerically simulates the root zone temperature of lettuce in the aeroponic cultivation box, after the box was sprayed with nutrient solutions of different temperatures. Then, the root zone environments of aeroponic lettuce were monitored through experiments at three different temperatures: high temperature, normal temperature, and low temperature. Through comparison, it was learned that the error between the simulated and measured values at each point was smaller than 1.35℃; the maximum error at a single point was within 7.4%; overall, the mean relative error was merely 5.8%. The results prove that the proposed CFD simulation model is reasonable and effective. Our research provides a theoretical reference for optimizing the root zone temperature, regulating the spray of nutrient solutions at different temperatures, and building an energy-efficient efficient aeroponic cultivation system.

Effect of low root-zone temperature on nodule initiation in narrow-leafed lupin (Lupinus angustifolius L.)

2002 ◽  
Vol 53 (3) ◽  
pp. 355 ◽  
Author(s):  
Sally C. Peltzer ◽  
Lynette K. Abbott ◽  
Craig A. Atkins
Keyword(s):  
Low Temperature ◽  
Root Zone ◽  
Lupinus Angustifolius ◽  
Nodule Development ◽  
Culture Solution ◽  
Mineral N ◽  
Root Zone Temperature ◽  
Low Root Zone Temperature ◽  
Nodule Initiation ◽  
Zone Temperature

The effect of low root-zone temperature on nodulation of Lupinus angustifolius [L.] cv. Yandee was studied using glasshouse experiments in which the effects of temperature on nodule initiation and subsequent nodule development could be assessed separately. Low temperature (7 and 12˚C compared with 25˚C) reduced the growth of both uninoculated plants supplied with adequate mineral N and inoculated plants reliant on fixation alone for their N. However, even at 25˚C, growth of inoculated plants compared with plants supplied with mineral N was limited, and at lower temperatures nodulation was severely inhibited. The most sensitive stage to low root-zone temperature was nodule initiation and there appeared to be a critical temperature between 7 and 12˚C at which initiation did not take place. Increasing the number of bacteria in inocula (from 5 × 103 to 5 × 107 viable cells/mL) did not overcome inhibition. A number of diverse cultivars of L. angustifolius showed the same response as cv. Yandee. Low temperature inhibition of nodule initiation could be overcome by addition of culture solution collected from around the roots of symbioses established at 25˚C. The culture solutions were only effective if the roots at 25˚C were inoculated or, if collected from around uninoculated roots of plants grown with mineral N, they were first exposed to a Bradyrhizobium suspension and then sterilised before addition to cultures at low temperature. The data indicate that both plant and bradyrhizobial factors are required for nodule initiation and that exudation of plant factors at low root-zone temperature is insufficient to stimulate production of the nodulation factors from Bradyrhizobium. At 25˚C, the nodulation zone of lupin roots bore many fractures in the epidermis and showed a high frequency of free root cap border cells, as well as a distinct matrix of extracellular material. These features were significantly reduced at 12˚C and essentially absent at 7˚C, indicating that at low temperature bacterial entry may be restricted.

Physiology and metabolism of grafted bell pepper in response to low root-zone temperature

2019 ◽  
Vol 46 (4) ◽  
pp. 339 ◽  
Author(s):  
Moses Kwame Aidoo ◽  
Tal Sherman ◽  
Naftali Lazarovitch ◽  
Aaron Fait ◽  
Shimon Rachmilevitch
Keyword(s):  
Gas Exchange ◽  
Low Temperature ◽  
Root Zone ◽  
Dry Mass ◽  
Bell Pepper ◽  
Gas Chromatography Mass Spectrometry ◽  
Limiting Factor ◽  
Root Zone Temperature ◽  
Low Root Zone Temperature ◽  
Zone Temperature

Low temperature is a prominent limiting factor for tropical originated crops production in temperate regions, particularly during cool-season production. The diverse response of two rootstocks (Canon-sensitive and S103-tolerant to low root-zone temperature) was studied when exposed to aeroponically different temperature regimes at the root zone: constant low temperature of 14°C low root-zone temperature (LRZT), transient exposure to LRZT of 27–14−27°C and control temperature of 27°C. Gas exchange, shoot dry mass, and root morphology were measured. Shifts in central and secondary metabolite levels in the leaves and roots were examined by gas chromatography-mass spectrometry (GC-MS). Low root-zone temperature inhibited photosynthesis and transpiration of both grafted bell pepper plants; however, self-grafted Canon physiology was impeded to a greater extent compared with Canon grafted onto rootstock S103. Rootstock S103 demonstrated higher sink potential contributing to milder reduction of photosynthesis and transpiration during stress compared with self-grafted Canon. This reduction of gas exchange led to a significant reduction of root maximum length and root dry mass in self-grafted Canon in response to the stress at 14°C compared with Canon grafted onto rootstock S103. In response to stress, GC-MS metabolite profiling showed enhance metabolism in both cultivars’ leaves, as well as in the roots irrespective of the developmental stage of the plant. This evidence combined indicates enhance gas exchange and carbon assimilation when bell pepper is grafted on S103 under low root-zone temperature.

scholarly journals Effect of Root-Zone Temperature on the Growth and Fruit Quality of Hydroponically Grown Strawberry Plants

2016 ◽  
Vol 8 (5) ◽  
pp. 122 ◽  
Author(s):  
Sakamoto Masaru ◽  
Mayuka Uenishi ◽  
Kengo Miyamoto ◽  
Takahiro Suzuki
Keyword(s):  
Low Temperature ◽  
Fruit Quality ◽  
Root Zone ◽  
Leaf Growth ◽  
Leafy Vegetables ◽  
Reproductive Growth ◽  
Root Zone Temperature ◽  
Hydroponically Grown ◽  
Zone Temperature

<p>It has been reported that soil temperature modulates the growth and quality of many leafy vegetables and some fruit vegetables; however, this effect has not been sufficiently reported for strawberry plants. Here using a deep flow technique hydroponic system, we investigated the effect of various root-zone temperatures (10 °C, 20 °C, and 30 °C) on the plant growth and fruit quality of strawberry plants grown at an air temperature of 20 °C. The high root-zone temperature treatment (30 °C) decreased oxygen consumption and cell viability of the roots, resulting in withering of most of the plants after 2 months of treatment. In contrast, roots exposed to low temperature (10 °C) showed higher biomass production than those exposed to ambient condition (20 °C), whereas leaf growth was only slightly influenced. The biomass of reproductive organs, such as inflorescences and fruits, were increased in plants treated with a low root-zone temperature, suggesting the activation of reproductive growth by low temperature. However, the contents of ascorbic acid and sugar in fruits were not significantly influenced by the cooling of the root-zone, although the fruit maturation period was significantly prolonged by low temperature. These data indicate that manipulation of root-zone temperature could alter the vegetative and reproductive growth of hydroponically grown strawberry plants.</p>

INFLUENCE OF NITROGEN, POTASSIUM AND ROOT ZONE TEMPERATURE ON THE RESPONSE OF TIMOTHY IN MONOCULTURE AND IN ASSOCIATION WITH ALFALFA AND BIRDSFOOT TREFOIL

1970 ◽  
Vol 50 (4) ◽  
pp. 401-409 ◽  
Author(s):  
HERMAN A. HAMILTON
Keyword(s):  
Soil Temperature ◽  
Significant Interaction ◽  
Root Zone ◽  
Nitrogen Addition ◽  
Birdsfoot Trefoil ◽  
Root Zone Temperature ◽  
Plant Associations ◽  
Different Temperatures ◽  
Soil Temperatures ◽  
Zone Temperature

The response of timothy in monoculture and m association with each of alfalfa and birdsfoot trefoil was studied when root zone temperatures of 10, 18.3 and 26.7 C were imposed on a soil receiving N at 0 and 100 pp2m of soil in all possible combinations with K at 0 and 166 pp2m of soil. The different plant associations resulted in highly significant differences in yields, irrespective of soil temperature or nitrogen addition, but only at 10 C was there a significant interaction between K and the plant associations. The legumes associated with timothy had a significant effect on timothy yield at all temperatures, and the behavior of the different legumes was in turn differently affected by fertilizer nutrients as well as by different temperatures. Shoot to root ratios of timothy tended to be greater when associated with trefoil than with alfalfa at all soil temperatures. The effect of soil temperature and fertilizer varied for alfalfa vs. trefoil when either was grown with timothy.

scholarly journals Insulative effect of plastic mulch systems and comparison between the effects of different plant types

2020 ◽  
Vol 5 (1) ◽  
pp. 317-324
Author(s):  
Kayla Snyder ◽  
Christopher Murray ◽  
Bryon Wolff
Keyword(s):  
Soil Moisture ◽  
Root Zone ◽  
Plastic Mulch ◽  
Root Zone Temperature ◽  
Tomato Plants ◽  
Black Film ◽  
Black And White ◽  
Mulch Film ◽  
Mulch Films ◽  
Zone Temperature

AbstractTo address agricultural needs of the future, a better understanding of plastic mulch film effects on soil temperature and moisture is required. The effects of different plant type and mulch combinations were studied over a 3.5-month period to better grasp the consequence of mulch on root zone temperature (RZT) and moisture. Measurements of (RZT) and soil moisture for tomato (Solanum lycopersicum), pepper (Capsicum annuum) and carrot (Daucus carota) grown using polyolefin mulch films (black and white-on-black) were conducted in Ontario using a plot without mulch as a control. Black mulch films used in combination with pepper and carrot plants caused similar RZTs relative to uncovered soil, but black mulch film in combination with tomato plants caused a reduction in RZT relative to soil without mulch that increased as plants grew and provided more shade. White-on-black mulch film used in combination with tomatoes, peppers or carrots led to a reduction in RZT relative to soil without mulch that became greater than the temperature of soil without mulch. This insulative capability was similarly observed for black mulch films used with tomato plants. Apart from white-on-black film used in combination with tomatoes, all mulch film and plant combinations demonstrated an ability to stabilize soil moisture relative to soil without mulch. RZT and soil moisture were generally stabilized with mulch film, but some differences were seen among different plant types.

EMERGENCE AND SEEDLING GROWTH OF INBRED LINES OF CORN AT SUBOPTIMAL ROOT-ZONE TEMPERATURES

1987 ◽  
Vol 67 (2) ◽  
pp. 409-415 ◽  
Author(s):  
A. MENKIR ◽  
E. N. LARTER
Keyword(s):  
Zea Mays ◽  
Seedling Growth ◽  
Root Zone ◽  
Seedling Emergence ◽  
Correlation Coefficients ◽  
Dry Weight ◽  
Inbred Lines ◽  
Root Zone Temperature ◽  
Emergence Percentage ◽  
Zone Temperature

Based on the results of an earlier paper, 12 inbred lines of corn (Zea mays L.) were evaluated for emergence and seedling growth at three controlled root-zone temperatures (10, 14, and 18 °C). Low root-zone temperatures, 10 and 14 °C, were detrimental to emergence, seedling growth, and root growth of all inbred lines. Differential responses of inbred lines were observed within each temperature regime. The differences in seedling emergence among lines became smaller with increasing root-zone temperature, while the reverse was true for seedling dry weight. Simple correlation coefficients showed a significantly (P = 0.05) negative association between emergence percentage and emergence index (rate). Neither of these two emergence traits was significantly correlated with seedling dry weights. Seedling dry weights were significantly (P = 0.01) and positively associated with root dry weights. Two inbred lines exhibited good tolerance to low root-zone temperatures, viz. CO255 and RB214. A significant and positive correlation existed between emergence percentage at a root-zone temperature of 10 °C and field emergence in test with the same genotypes reported earlier. Selection at a root-zone temperature of 10 °C for a high percentage of seedling emergence, therefore, could be effective in identifying genotypes capable of germinating in cool soils. Furthermore, the significantly (P = 0.01) positive relationship between seedling dry weights at all root-zone temperatures and those from the field test suggest that strains with vigorous seedling growth in the field could be identified using low root-zone temperature regimes.Key words: Zea mays, root-zone temperature, cold tolerance

Effects of root zone temperature on root initiation and elongation in red pine seedlings

1986 ◽  
Vol 16 (4) ◽  
pp. 696-700 ◽  
Author(s):  
Chris P. Andersen ◽  
Edward I. Sucoff ◽  
Robert K. Dixon
Keyword(s):  
Root Elongation ◽  
Root Zone ◽  
Soluble Sugar ◽  
Soluble Sugars ◽  
Red Pine ◽  
Root Tip ◽  
Root Initiation ◽  
Root Zone Temperature ◽  
Pine Seedlings ◽  
Zone Temperature

The influence of root zone temperature on root initiation, root elongation, and soluble sugars in roots and shoots was investigated in a glasshouse using 2-0 red pine (Pinusresinosa Ait.) seedlings lifted from a northern Minnesota nursery. Seedlings were potted in a sandy loam soil and grown in chambers where root systems were maintained at 8, 12, 16, or 20 °C for 27 days; seedling shoots were exposed to ambient glasshouse conditions. Total new root length was positively correlated with soil temperature 14, 20, and 27 days after planting, with significantly more new root growth at 20 °C than at other temperatures. The greatest number of new roots occurred at 16 °C; the least, at 8 °C. Total soluble sugar concentrations in stem tissue decreased slightly as root temperature increased. Sugar concentrations in roots were similar at all temperatures. The results suggest that root elongation is suppressed more than root tip formation when red pine seedlings are exposed to the cool soil temperatures typically found during spring and fall outplanting.

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