Obtaining Spatial Air Temperature from Airborne Radiometric Crop Canopy Temperature

2002 ◽  
Author(s):  
Jose L. Chavez ◽  
Christopher M. U. Neale
Keyword(s):  
Air Temperature ◽  
Canopy Temperature ◽  
Crop Canopy

scholarly journals Intelligent thermal image-based sensor for affordable measurement of crop canopy temperature

2021 ◽  
Vol 188 ◽  
pp. 106319
Author(s):  
Jaime Giménez-Gallego ◽  
Juan D. González-Teruel ◽  
Fulgencio Soto-Valles ◽  
Manuel Jiménez-Buendía ◽  
Honorio Navarro-Hellín ◽  
...  
Keyword(s):  
Canopy Temperature ◽  
Thermal Image ◽  
Crop Canopy

scholarly journals The effect of environmental factors on the growth of alfalfa in the field.

1962 ◽  
Vol 10 (4) ◽  
pp. 247-253
Author(s):  
G. Stanhill
Keyword(s):  
Environmental Factors ◽  
Solar Radiation ◽  
Root Growth ◽  
Air Temperature ◽  
Meteorological Data ◽  
Crop Canopy

DM production from a heavily fertilized lucerne crop grown at Gilat and irrigated daily was compared with potential photosynthesis calculated from meteorological data [see F.C.A. 12: 1940]. After corrections were applied for losses due to respiration, root growth and light wasted beneath the crop canopy, calculated amounts agreed well with those measured. The percentage of light utilized was 33% with cutting at 31-day intervals and 46% with cutting at 48-day intervals. DM production was correlated positively with solar radiation and negatively with air temperature.-R.B. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Monitoring canopy and air temperature of dominant vegetation in tropical semi-arid using bioclimatic model

2016 ◽  
Vol 1 (1) ◽  
pp. 1-12
Author(s):  
Josiclêda Domiciano Galvíncio ◽  
Rejane Magalhães de Mendonça Pimentel
Keyword(s):  
Climate Change ◽  
Air Temperature ◽  
Dominant Species ◽  
Canopy Temperature ◽  
Leaf Temperature ◽  
Climate Change Scenarios ◽  
Arid Environments ◽  
Intergovernmental Panel ◽  
Dry Land ◽  
Bioclimatic Model

Typical vegetation of arid environments consists of few dominant species highly threatened by climate change. Jurema preta (Mimosa tenuiflora (Willd.) Poiret) is one of these successful species that now is dominant in extensive semiarid areas in the world. The development of a simple bioclimatic model using climate change scenarios based on optimistic and pessimistic predictions of the Intergovernmental Panel on Climate Change (IPCC) shown as a simple tool to predict possible responses of dominant species under dry land conditions and low functional biodiversity. The simple bioclimatic model proved satisfactory in creating climate change scenarios and impacts on the canopy temperature of Jurema preta in semiarid Brazil. The bioclimatic model was efficient to obtain spatially relevant estimations of air temperature from determinations of the surface temperature using satellite images. The model determined that the average difference of 5oC between the air temperature and the leaf temperature for Jurema preta, and an increase of 3oC in air temperature, promote an increase of 2oC in leaf temperature. It leads to disturbances in vital physiological mechanisms in the leaf, mainly the photosynthesis and efficient use of water.

<i>Analysis on diurnal variation of crop canopy temperature in solar greenhouse</i>

2020 ◽  
Author(s):  
Junhua Zhang ◽  
Kaichen Shen ◽  
Danyan Chen ◽  
Pan Gao ◽  
Jin Hu ◽  
...  
Keyword(s):  
Diurnal Variation ◽  
Canopy Temperature ◽  
Crop Canopy ◽  
Solar Greenhouse

Estimation of evapotranspiration using the crop canopy temperature at field to regional scales in large irrigation district

2019 ◽  
Vol 269-270 ◽  
pp. 305-322 ◽  
Author(s):  
Lingxu Huang ◽  
Jiabing Cai ◽  
Baozhong Zhang ◽  
He Chen ◽  
Liangliang Bai ◽  
...  
Keyword(s):  
Canopy Temperature ◽  
Irrigation District ◽  
Crop Canopy ◽  
Large Irrigation

An infrared-based coefficient to screen plant environmental stress: concept, test and applications

2009 ◽  
Vol 36 (11) ◽  
pp. 990 ◽  
Author(s):  
Guo Yu Qiu ◽  
Kenji Omasa ◽  
Sadanori Sase
Keyword(s):  
Heat Stress ◽  
Water Stress ◽  
Environmental Stress ◽  
Air Temperature ◽  
Canopy Temperature ◽  
Water Shortage ◽  
Leaf Temperature ◽  
Stress Index ◽  
Crop Water Stress Index ◽  
Water Stress Index

By introducing a reference dry leaf (a leaf without transpiration), a formerly proposed plant transpiration transfer coefficient (hat) was applied to detect environmental stress caused by water shortage and high temperature on melon, tomato and lettuce plants under various conditions. Results showed that there were obvious differences between leaf temperature, dry reference leaf temperature and air temperature. The proposed coefficient hat could integrate the three temperatures and quantitatively evaluate the environmental stress of plants. Experimental results showed that the water stress of melon plants under two irrigation treatments was clearly distinguished by using the coefficient. The water stress of a tomato plant as the soil dried under a controlled environmental condition was sensitively detected by using hat. A linear relationship between hat and conventional crop water stress index was revealed with a regression determination coefficient R2 = 0.97. Further, hat was used to detect the heat stress of lettuce plants under high air temperature conditions (28.7°C) with three root temperature treatments (21.5, 25.9 and 29.5°C). The canopy temperature under these treatments was respectively 26.44, 27.15 and 27.46°C and the corresponding hat value was –1.11, –0.74 and –0.59. Heat stress was also sensitively detected using hat. The main advantage of hat is its simplicity for use in infrared applications.

Influence of agronomic practices on canopy microclimate and septoria development in no-till winter wheat produced in the Parkland region of Saskatchewan

1993 ◽  
Vol 73 (1) ◽  
pp. 331-344 ◽  
Author(s):  
D. K. Tompkins ◽  
D. B. Fowler ◽  
A. T. Wright
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Air Temperature ◽  
Flag Leaf ◽  
Septoria Tritici ◽  
Yield Potential ◽  
High Yield ◽  
Crop Canopy ◽  
No Till ◽  
N Fertility

In areas with favourable growing conditions, high seeding rates (SRs), narrow row spacings (RSs) and nitrogen fertilization (N) are required before high yield potentials of winter wheat (Triticum aestivum L.) are realized. Changes in these variables produce changes in crop-canopy microclimate that may influence the development of foliar pathogens. This study examined the relative differences in crop-canopy microclimates due to different RS and SR combinations and determined the effect of SR, RS and N fertility on septoria (Septoria nodorum Berk. and Septoria tritici Rob. ex Desm.) development on normal height and semi-dwarf cultivars grown under no-till in the Parkland region of Saskatchewan. The daily mean value for solar radiation penetrating to the base of the crop canopy was 1100 μmol m−2 s−1 for 36-cm RS. This was 30% higher than the 845 μmol m−2 s−1 observed for 9-cm RS. The increased light interception by the canopy was associated with higher dry matter production and grain yield. During peak periods, wind speed was 56% higher within the 36-cm RS canopy than within the 9-cm RS canopy. Increased duration of leaf wetness was associated with 9-cm RS and 140-kg-ha−1 SR treatment. Cooler air temperature and higher RH within the canopy occurred for the 9-cm RS – 140-kg-ha−1 SR treatment. Differences in air temperature and RH between the 9-cm RS – 140-kg-ha−1 SR and the 36-cm RS – 35-kg-ha−1 SR treatments were smaller at night and greater during the day. The maximum differences occurred at mid-morning and mid-afternoon, when the 9-cm RS – 140-kg-ha−1 SR canopy was 1.5 °C cooler and had a 4.5% higher RH than the 36-cm RS – 35-kg-ha−1 SR canopy. Septoria severity increased when SR increased from 35 kg ha−1 to 140 kg ha−1. Septoria severity was not influenced by RS. Septoria severity was greater on the flag leaf of the semi-dwarf cultivar Norwin than on the tall cultivar Norstar. Increased N fertility reduced septoria severity in one trial. These observations demonstrated that, in addition to the influence on yield potential, high SR and narrow RS produce a canopy microclimate that is favourable for the development of septoria. Key words: Seed rate, row spacing, N fertility, Septoria sp., Triticum aestivum, canopy microclimate

scholarly journals Isoprene emissions track the seasonal cycle of canopy temperature, not primary production: evidence from remote sensing

2014 ◽  
Vol 11 (13) ◽  
pp. 3437-3451 ◽  
Author(s):  
P. N. Foster ◽  
I. C. Prentice ◽  
C. Morfopoulos ◽  
M. Siddall ◽  
M. van Weele
Keyword(s):  
Primary Production ◽  
Air Temperature ◽  
Seasonal Cycle ◽  
Gross Primary Production ◽  
Canopy Temperature ◽  
Remotely Sensed ◽  
Formaldehyde Concentration ◽  
Isoprene Emission ◽  
The Tropics ◽  
Better Than

Abstract. Isoprene is important in atmospheric chemistry, but its seasonal emission pattern – especially in the tropics, where most isoprene is emitted – is incompletely understood. We set out to discover generalized relationships applicable across many biomes between large-scale isoprene emission and a series of potential predictor variables, including both observed and model-estimated variables related to gross primary production (GPP) and canopy temperature. We used remotely sensed atmospheric concentrations of formaldehyde, an intermediate oxidation product of isoprene, as a proxy for isoprene emission in 22 regions selected to span high to low latitudes, to sample major biomes, and to minimize interference from pyrogenic sources of volatile organic compounds that could interfere with the isoprene signal. Formaldehyde concentrations showed the highest average seasonal correlations with remotely sensed (r = 0.85) and model-estimated (r = 0.80) canopy temperatures. Both variables predicted formaldehyde concentrations better than air temperature (r= 0.56) and a "reference" isoprene model that combines GPP and an exponential function of temperature (r = 0.49), and far better than either remotely sensed green vegetation cover, fPAR (r = 0.25) or model-estimated GPP (r = 0.14). Gross primary production in tropical regions was anti-correlated with formaldehyde concentration (r = −0.30), which peaks during the dry season. Our results were most reliable in the tropics, where formaldehyde observational errors were the least. The tropics are of particular interest because they are the greatest source of isoprene emission as well as the region where previous modelling attempts have been least successful. We conjecture that positive correlations of isoprene emission with GPP and air temperature (as found in temperate forests) may arise simply because both covary with canopy temperature, peaking during the relatively short growing season. The lack of a general correlation between GPP and formaldehyde concentration in the seasonal cycle is consistent with experimental evidence that isoprene emission rates are largely decoupled from photosynthetic rates, and with the likely adaptive significance of isoprene emission in protecting leaves against heat damage and oxidative stress.

scholarly journals Sudden changes in crop environment, as influenced by total solar eclipse

MAUSAM ◽  
2021 ◽  
Vol 49 (4) ◽  
pp. 511-520
Author(s):  
A. KASHYAPI ◽  
S. K. SHAHA ◽  
P. M. GULHANE
Keyword(s):  
Soil Temperature ◽  
Canopy Temperature ◽  
Total Solar Eclipse ◽  
The Other ◽  
Crop Canopy ◽  
Soil Temperature Gradient ◽  
Sunshine Hours ◽  
Crop Environment ◽  
Daily Total ◽  
Agricultural Meteorology

The Division of Agricultural Meteorology, at Pune of IMD conducted an experiment at Principal Evapotranspiration Observatory, Canning, W.B., during October, 1995 to study the sudden changes in crop environment. The present study revealed that both the crop canopy temperature and observatory temperature at different heights recorded sharp fall of around 2.0°C at 0900 hr (IST) on the eclipse day. The relative humidity (% ) increased sharply at 0900 hr (IST) on the eclipse day within crop canopy as well as within observatory. The soil temperature dropped suddenly at 10 and 20 cm depths of the subsoil and delayed reversal of the soil temperature gradient occurred on the eclipse day; the grass minimum temperature was 21.2°C. Bright sunshine hours reduced by 0.8 on 'the eclipse day as compared to the preceding and succeeding days. The wind during the eclipse period was almost calm between 0900 -0930 hr (IST). The daily total ET recorded on the eclipse day was the minimum. The rate of evapotranspiration was less than half as compared to the other days, as recorded at 0830 hr (IST) (0.2 mm) on the eclipse day, which was closely followed by that observed at 1130 hr (IST) (0.3 mm).

scholarly journals Canopy temperature and heat stress are increased by compound high air temperature and water stress and reduced by irrigation – a modeling analysis

2021 ◽  
Vol 25 (3) ◽  
pp. 1411-1423 ◽  
Author(s):  
Xiangyu Luan ◽  
Giulia Vico
Keyword(s):  
Heat Stress ◽  
Water Stress ◽  
Water Potential ◽  
Soil Water ◽  
Air Temperature ◽  
Water Availability ◽  
Plant Traits ◽  
Soil Water Potential ◽  
Canopy Temperature ◽  
Threshold Temperature

Abstract. Crop yield is reduced by heat and water stress and even more when these conditions co-occur. Yet, compound effects of air temperature and water availability on crop heat stress are poorly quantified. Existing crop models, by relying at least partially on empirical functions, cannot account for the feedbacks of plant traits and response to heat and water stress on canopy temperature. We developed a fully mechanistic model, coupling crop energy and water balances, to determine canopy temperature as a function of plant traits, stochastic environmental conditions, and irrigation applications. While general, the model was parameterized for wheat. Canopy temperature largely followed air temperature under well-watered conditions. But, when soil water potential was more negative than −0.14 MPa, further reductions in soil water availability led to a rapid rise in canopy temperature – up to 10 ∘C warmer than air at soil water potential of −0.62 MPa. More intermittent precipitation led to higher canopy temperatures and longer periods of potentially damaging crop canopy temperatures. Irrigation applications aimed at keeping crops under well-watered conditions could reduce canopy temperature but in most cases were unable to maintain it below the threshold temperature for potential heat damage; the benefits of irrigation in terms of reduction of canopy temperature decreased as average air temperature increased. Hence, irrigation is only a partial solution to adapt to warmer and drier climates.

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