scholarly journals Determination of Actual Evapotranspiration and Crop Coefficients of California Date Palms Using the Residual of Energy Balance Approach

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2253 ◽  
Author(s):  
Aliasghar Montazar ◽  
Robert Krueger ◽  
Dennis Corwin ◽  
Alireza Pourreza ◽  
Cayle Little ◽  
...  
Keyword(s):  
Energy Balance ◽  
Water Resources ◽  
Date Palm ◽  
Irrigation Management ◽  
Canopy Cover ◽  
Tree Height ◽  
Actual Evapotranspiration ◽  
Date Palms ◽  
The Mean ◽  
Crop Coefficients

As water scarcity becomes of greater concern in arid and semi-arid regions due to altered weather patterns, greater and more accurate knowledge regarding evapotranspiration of crops produced in these areas is of increased significance to better manage limited water resources. This study aimed at determining the actual evapotranspiration (ETa) and crop coefficients (Ka) in California date palms. The residual of energy balance method using a combination of surface renewal and eddy covariance techniques was applied to measure ETa in six commercial mature date palm orchards (8–22 years old) over one year. The experimental orchards represent various soil types and conditions, irrigation management practices, canopy characteristics, and the most common date cultivars in the region. The results demonstrated considerable variability in date palm consumptive water use, both spatially and temporally. The cumulative ETa (CETa) across the six sites ranged from 1299 to 1501 mm with a mean daily ETa of 7.2 mm day−1 in June–July and 1.0 mm day−1 in December at the site with the highest crop water consumption. The mean monthly Ka values varied between 0.63 (December) and 0.90 (June) in the non-salt-affected, sandy loam soil date palms with an average density of 120 plants ha−1 and an average canopy cover and tree height of more than 80% and 11.0 m, respectively. However, the values ranged from 0.62 to 0.75 in a silty clay loam saline-sodic date palm orchard with 55% canopy cover, density of 148 plants ha−1, and 7.3 m tree height. Inverse relationships were derived between the CETa and soil salinity (ECe) in the crop root zone; and between the mean annual Ka and ECe. This information addresses the immediate needs of date growers for irrigation management in the region and enables them to more efficiently utilize water and to achieve full economic gains in a sustainable manner, especially as water resources become less available or more expensive.

scholarly journals Evaluation of a Hybrid Reflectance-Based Crop Coefficient and Energy Balance Evapotranspiration Model for Irrigation Management

2018 ◽  
Vol 61 (2) ◽  
pp. 533-548 ◽  
Author(s):  
J. Burdette Barker ◽  
Christopher M. U. Neale ◽  
Derek M. Heeren ◽  
Andrew E. Suyker
Keyword(s):  
Remote Sensing ◽  
Energy Balance ◽  
Water Balance ◽  
Real Time ◽  
Eddy Covariance ◽  
Irrigation Management ◽  
Crop Coefficient ◽  
Irrigation Scheduling ◽  
Balance Model ◽  
Crop Coefficients

Abstract. Accurate generation of spatial soil water maps is useful for many types of irrigation management. A hybrid remote sensing evapotranspiration (ET) model combining reflectance-based basal crop coefficients (Kcbrf) and a two-source energy balance (TSEB) model was modified and validated for use in real-time irrigation management. We modeled spatial ET for maize and soybean fields in eastern Nebraska for the 2011-2013 growing seasons. We used Landsat 5, 7, and 8 imagery as remote sensing inputs. In the TSEB, we used the Priestly-Taylor (PT) approximation for canopy latent heat flux, as in the original model formulations. We also used the Penman-Monteith (PM) approximation for comparison. We compared energy balance fluxes and computed ET with measurements from three eddy covariance systems within the study area. Net radiation was underestimated by the model when data from a local weather station were used as input, with mean bias error (MBE) of -33.8 to -40.9 W m-2. The measured incident solar radiation appeared to be biased low. The net radiation model performed more satisfactorily when data from the eddy covariance flux towers were input into the model, with MBE of 5.3 to 11.2 W m-2. We removed bias in the daily energy balance ET using a dimensionless multiplier that ranged from 0.89 to 0.99. The bias-corrected TSEB ET, using weather data from a local weather station and with local ground data in thermal infrared imagery corrections, had MBE = 0.09 mm d-1 (RMSE = 1.49 mm d-1) for PM and MBE = 0.04 mm d-1 (RMSE = 1.18 mm d-1) for PT. The hybrid model used statistical interpolation to combine the two ET estimates. We computed weighting factors for statistical interpolation to be 0.37 to 0.50 for the PM method and 0.56 to 0.64 for the PT method. Provisions were added to the model, including a real-time crop coefficient methodology, which allowed seasonal crop coefficients to be computed with relatively few remote sensing images. This methodology performed well when compared to basal crop coefficients computed using a full season of input imagery. Water balance ET compared favorably with the eddy covariance data after incorporating the TSEB ET. For a validation dataset, the magnitude of MBE decreased from -0.86 mm d-1 (RMSE = 1.37 mm d-1) for the Kcbrf alone to -0.45 mm d-1 (RMSE = 0.98 mm d-1) and -0.39 mm d-1 (RMSE = 0.95 mm d-1) with incorporation of the TSEB ET using the PM and PT methods, respectively. However, the magnitudes of MBE and RMSE were increased for a running average of daily computations in the full May-October periods. The hybrid model did not necessarily result in improved model performance. However, the water balance model is adaptable for real-time irrigation scheduling and may be combined with forecasted reference ET, although the low temporal frequency of satellite imagery is expected to be a challenge in real-time irrigation management. Keywords: Center-pivot irrigation, ET estimation methods, Evapotranspiration, Irrigation scheduling, Irrigation water balance, Model validation, Variable-rate irrigation.

Biology and control of the dubas bug, Ommatissus binotatus lybicus de Berg. (Homoptera, Tropiduchidae), infesting date palms in Iraq

1963 ◽  
Vol 53 (4) ◽  
pp. 737-745 ◽  
Author(s):  
Ali A. Hussain
Keyword(s):  
Date Palm ◽  
Coccinella Septempunctata ◽  
Population Level ◽  
Phoenix Dactylifera ◽  
Date Palms ◽  
Summer Generation ◽  
Chrysopa Carnea ◽  
Two Generations ◽  
The Mean ◽  
And Control

The dubas bug, Ommatissus binotatus lybicus de Berg, is a serious pest of the date palm (Phoenix dactylifera) in Iraq, where there are two generations a year. Both nymphs and adults, which are described, suck the sap from the date palm. Repeated heavy infestations cause the weakening and death of some of the palms.The eggs are laid on all the green parts of the palm except the fruits, the majority on the leaflets, especially the upper surface. They are distributed evenly on the four aspects of the date palms, but unevenly on the frond rows, the second and fourth oldest rows having the majority of the eggs in the overwintering and summer generations, respectively. Deposition of eggs of the overwintering generation began in the second week of November and hatching started during the first week of April, the nymphal period lasting 47 days and the adults surviving for 15 days. Eggs of the summer generation were deposited from the second week of June, and hatching started in the first week of August, the nymphal period lasting 50 days and the adults surviving for 13 days. There are five nymphal instars.The nymphs excreted droplets of honeydew, and both nymphs and adults prefer the shady parts of the date palm. In order to escape the severe heat of the summer days, the nymphs and adults of the overwintering generation migrated towards the bases of the new fronds. The sex ratio was nearly 1:1, and the mean number of eggs laid per female was 106. The mortality rate for a constant population level was 98·11 per cent.The eggs were parasitised by a small Chalcidoid. The larvae of the lace wing Chrysopa carnea Steph. and the adults of Coccinella septempunctata L., C. undecimpunctata L., and Chilocorus bipustulatus (L.) preyed upon the nymphs and adults.In tests with inseeticidal sprays containing 240 g. active ingredient per 100 gal. applied at the rate of 1½ gal. per palm against adults and nymphs, DDT and malathion were equally effective, but Dipterex was less so. Similar concentrations of mixtures of malathion with heptachlor and DDT with diazinon were also effective.

Biodiversity of date palms ( Phoenix dactylifera L.) in Sudan: chemical, morphological and DNA polymorphisms of selected cultivars

2009 ◽  
Vol 7 (02) ◽  
pp. 194-203 ◽  
Author(s):  
Sakina Elshibli ◽  
Helena Korpelainen
Keyword(s):  
Date Palm ◽  
Chemical Characterization ◽  
Tree Height ◽  
Titratable Acidity ◽  
Fruit Weight ◽  
Dna Polymorphisms ◽  
Large Set ◽  
High Genetic Diversity ◽  
Date Palms ◽  
Wide Range

Date palm fruits of 15 cultivars were collected at harvest (Tamr stage) from the Nori Horticultural Orchard in the Northern State of Sudan for morphological and chemical characterization. Morphological and DNA polymorphisms of the mother trees were also investigated. Significant (P < 0.001) differentiation of cultivars in relation to tree height, and number and length of pinnae and spines was observed. Fruit weight, flesh weight and fruit and seed sizes expressed a wide range of diversity among cultivars. Significant differences were also observed among cultivars for all tested sugars (P < 0.001). Titratable acidity was found to be a characteristic feature of almost every cultivar. The results of DNA genotyping indicated high genetic diversity among cultivars with Nei's genetic distances ranging from 0.693 to 3.496, and expected and observed heterozygosity equalling 0.837 and 0.950, respectively. This study highlights the diversity of date palms in Sudan, as represented by apparent morphological characters, chemical composition of fruits as well as DNA polymorphism. The employment of different techniques for data analyses gave conclusive ideas on some interrelationships among a large set of characters; the knowledge of such relationships can be utilized for screening date palm cultivars for possible descriptors.

­Actual Evapotranspiration for Sugarcane Based on Bowen Ratio-Energy Balance and Soil Water Balance Models with Optimized Crop Coefficients.

2021 ◽  
Author(s):  
Suelen da Costa Faria Martins ◽  
Marcos Alex dos Santos ◽  
Gustavo Bastos Lyra ◽  
José Leonaldo Souza ◽  
Guilherme Bastos Lyra ◽  
...  
Keyword(s):  
Energy Balance ◽  
Water Balance ◽  
Soil Water ◽  
Bowen Ratio ◽  
Balance Method ◽  
Northeastern Brazil ◽  
Soil Water Balance ◽  
Actual Evapotranspiration ◽  
Crop Coefficients ◽  
Ratio Energy

Abstract Evapotranspiration is an important parameter to evaluate soil water deficit and water use efficiency, especially at places with irregularly distributed precipitation.The aim of this study was to assess the daily actual evapotranspiration (ETa) estimated by the Thornthwaite and Mather soil water balance method adapted for crops (ThM) and by the dual Kc approach with the crop coefficients optimized from inversing modeling and by the adjustment procedure suggested in FAO-56. The models comparison and optimization were performed with actual evapotranspiration determined by the Bowen ratio – energy balance method (ETβ) for sugarcane at full canopy closure grown in Alagoas State, Northeastern Brazil. The objective function of the inverse problem was defined in terms of ETβ and ETa estimated by the ThM and dual Kc method by optimizing single crop coefficient (Kc) and the basal coefficient Kcb, respectively. Both optimized Kcand Kcbwere lower than the adjusted KcFAO56, with optimized Kconly 3% less than the Kc obtained experimentally. ETa estimated by ThM and dual Kc models with optimized crop coefficients (Kc = 1.05 or Kcb = 1.00) had similar high precision (r² >0.79) and accuracy (dm>0.93 and RMSE < 0.30 mm d-1), whereas using the coefficients derived from FAO 56 overestimated ETa in both models.

Annual Evapotranspiration and Crop Coefficients of Ligustrum japonica Growing in Three Container Sizes

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 512c-512
Author(s):  
R.C. Beeson
Keyword(s):  
Reference Evapotranspiration ◽  
Actual Evapotranspiration ◽  
Rooted Cuttings ◽  
Supplemental Irrigation ◽  
Mean Size ◽  
Crop Coefficients ◽  
Marketable Size

The objective of this study was to determine crop coefficients (KC) for Ligustrum japonica growing in three container sizes using the Penman equation to calculate reference evapotranspiration (ETR). Rooted cuttings were transplanted into 3-liter containers and upcanned as needed into 10- and 23-L containers. Production was scheduled such that a series of plants in each container size were about 2 months from commercial marketable size every 4 months. Beginning 1 Jan. 1995 until 31 Dec. 1996, three uniform plants of each size were suspended in weighing lysimeters and surrounded by similar size plants filling an area 3.7 by 4.9 m. Plants within each area were overhead irrigated at 2000 h as needed, based on a 30% moisture allowed deficit. Plants were exchanged every 4 months such that the annual mean size was that of a marketable plant. Actual evapotranspiration (ETA) was calculated from half-hour measurements of each plant's weight and adjusted for rainfall. From these and daily calculated ETR, KC were determined for each size of container. KCs ranged from 1.06 to 1.50 when ETA was converted to mm/day based on allocated bed space. Comparisons of volumes of supplemental irrigation to ETA and effects of assumptions required in converting ETA to mm/day will be discussed.

scholarly journals Development and Performance Evaluation of a Very Low-Cost UAV-Lidar System for Forestry Applications

2020 ◽  
Vol 13 (1) ◽  
pp. 77
Author(s):  
Tianyu Hu ◽  
Xiliang Sun ◽  
Yanjun Su ◽  
Hongcan Guan ◽  
Qianhui Sun ◽  
...  
Keyword(s):  
Forest Inventory ◽  
Low Cost ◽  
Canopy Cover ◽  
Tree Height ◽  
Flying Height ◽  
Tree Level ◽  
Forest Site ◽  
Lidar System ◽  
Individual Tree ◽  
Gap Fraction

Accurate and repeated forest inventory data are critical to understand forest ecosystem processes and manage forest resources. In recent years, unmanned aerial vehicle (UAV)-borne light detection and ranging (lidar) systems have demonstrated effectiveness at deriving forest inventory attributes. However, their high cost has largely prevented them from being used in large-scale forest applications. Here, we developed a very low-cost UAV lidar system that integrates a recently emerged DJI Livox MID40 laser scanner (~$600 USD) and evaluated its capability in estimating both individual tree-level (i.e., tree height) and plot-level forest inventory attributes (i.e., canopy cover, gap fraction, and leaf area index (LAI)). Moreover, a comprehensive comparison was conducted between the developed DJI Livox system and four other UAV lidar systems equipped with high-end laser scanners (i.e., RIEGL VUX-1 UAV, RIEGL miniVUX-1 UAV, HESAI Pandar40, and Velodyne Puck LITE). Using these instruments, we surveyed a coniferous forest site and a broadleaved forest site, with tree densities ranging from 500 trees/ha to 3000 trees/ha, with 52 UAV flights at different flying height and speed combinations. The developed DJI Livox MID40 system effectively captured the upper canopy structure and terrain surface information at both forest sites. The estimated individual tree height was highly correlated with field measurements (coniferous site: R2 = 0.96, root mean squared error/RMSE = 0.59 m; broadleaved site: R2 = 0.70, RMSE = 1.63 m). The plot-level estimates of canopy cover, gap fraction, and LAI corresponded well with those derived from the high-end RIEGL VUX-1 UAV system but tended to have systematic biases in areas with medium to high canopy densities. Overall, the DJI Livox MID40 system performed comparably to the RIEGL miniVUX-1 UAV, HESAI Pandar40, and Velodyne Puck LITE systems in the coniferous site and to the Velodyne Puck LITE system in the broadleaved forest. Despite its apparent weaknesses of limited sensitivity to low-intensity returns and narrow field of view, we believe that the very low-cost system developed by this study can largely broaden the potential use of UAV lidar in forest inventory applications. This study also provides guidance for the selection of the appropriate UAV lidar system and flight specifications for forest research and management.

scholarly journals Adjudicating Perspectives on Forest Structure: How Do Airborne, Terrestrial, and Mobile Lidar-Derived Estimates Compare?

2021 ◽  
Vol 13 (12) ◽  
pp. 2297
Author(s):  
Jonathon J. Donager ◽  
Andrew J. Sánchez Meador ◽  
Ryan C. Blackburn
Keyword(s):  
Ponderosa Pine ◽  
Laser Scanning ◽  
Canopy Cover ◽  
Basal Area ◽  
Tree Height ◽  
Absolute Error ◽  
Forest Monitoring ◽  
Individual Tree ◽  
Structural Configurations ◽  
Individual Trees

Applications of lidar in ecosystem conservation and management continue to expand as technology has rapidly evolved. An accounting of relative accuracy and errors among lidar platforms within a range of forest types and structural configurations was needed. Within a ponderosa pine forest in northern Arizona, we compare vegetation attributes at the tree-, plot-, and stand-scales derived from three lidar platforms: fixed-wing airborne (ALS), fixed-location terrestrial (TLS), and hand-held mobile laser scanning (MLS). We present a methodology to segment individual trees from TLS and MLS datasets, incorporating eigen-value and density metrics to locate trees, then assigning point returns to trees using a graph-theory shortest-path approach. Overall, we found MLS consistently provided more accurate structural metrics at the tree- (e.g., mean absolute error for DBH in cm was 4.8, 5.0, and 9.1 for MLS, TLS and ALS, respectively) and plot-scale (e.g., R2 for field observed and lidar-derived basal area, m2 ha−1, was 0.986, 0.974, and 0.851 for MLS, TLS, and ALS, respectively) as compared to ALS and TLS. While TLS data produced estimates similar to MLS, attributes derived from TLS often underpredicted structural values due to occlusion. Additionally, ALS data provided accurate estimates of tree height for larger trees, yet consistently missed and underpredicted small trees (≤35 cm). MLS produced accurate estimates of canopy cover and landscape metrics up to 50 m from plot center. TLS tended to underpredict both canopy cover and patch metrics with constant bias due to occlusion. Taking full advantage of minimal occlusion effects, MLS data consistently provided the best individual tree and plot-based metrics, with ALS providing the best estimates for volume, biomass, and canopy cover. Overall, we found MLS data logistically simple, quickly acquirable, and accurate for small area inventories, assessments, and monitoring activities. We suggest further work exploring the active use of MLS for forest monitoring and inventory.

scholarly journals Genetic diversity and population structure of date palms (Phoenix dactylifera L.) in Ethiopia using microsatellite markers

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Workia Ahmed ◽  
Tileye Feyissa ◽  
Kassahun Tesfaye ◽  
Sumaira Farrakh
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Microsatellite Markers ◽  
Information Content ◽  
Date Palm ◽  
Polymorphic Information Content ◽  
Phoenix Dactylifera ◽  
Mean Value ◽  
Date Palms ◽  
Expected Heterozygosity

Abstract Background Date palm tree (Phoenix dactylifera L.) is a perennial monocotyledonous plant belonging to the Arecaceae family, a special plant with extraordinary nature that gives eminent contributions in agricultural sustainability and huge socio-economic value in many countries of the world including Ethiopia. Evaluation of genetic diversity across date palms at DNA level is very important for breeding and conservation. The result of this study could help to design for genetic improvement and develop germplasm introduction programmes of date palms mainly in Ethiopia. Results In this study, 124 date palm genotypes were collected, and 10 polymorphic microsatellite markers were used. Among 10 microsatellites, MPdCIR085 and MPdCIR093 loci showed the highest value of observed and expected heterozygosity, maximum number of alleles, and highest polymorphic information content values. A total of 112 number of alleles were found, and the mean number of major allele frequency was 0.26, with numbers ranging from 0.155 (MPdCIR085) to 0.374 (MPdCIR016); effective number of alleles with a mean value of 6.61, private alleles ranged from 0.0 to 0.65; observed heterozygosity ranged from 0.355 to 0.726; expected heterozygosity varied from 0.669 to 0.906, polymorphic information content with a mean value of 0.809; fixation index individuals relative to subpopulations ranged from 0.028 for locus MPdCIR032 to 0.548 for locus MPdCIR025, while subpopulations relative to total population value ranged from − 0.007 (MPdCIR070) to 0.891 (MPdCIR015). All nine accesstions, neighbour-joining clustering analysis, based on dissimilarity coefficient values were grouped into five major categories; in population STRUCTURE analysis at highest K value, three groups were formed, whereas DAPC separated date palm genotypes into eight clusters using the first two linear discriminants. Principal coordinate analysis was explained, with a 17.33% total of variation in all populations. Generally, the result of this study revealed the presence of allele variations and high heterozygosity (> 0.7) in date palm genotypes. Conclusions Microsatellites (SSR) are one of the most preferable molecular markers for the study of genetic diversity and population structure of plants. In this study, we found the presence of genetic variations of date palm genotypes in Ethiopia; therefore, these genetic variations of date palms is important for crop improvement and conservation programmes; also, it will be used as sources of information to national and international genbanks.

Surface energy balance model of transpiration from variable canopy cover and evaporation from residue-covered or bare-soil systems

2009 ◽  
Vol 28 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Luis Octavio Lagos ◽  
Derrel L. Martin ◽  
Shashi B. Verma ◽  
Andrew Suyker ◽  
Suat Irmak
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Canopy Cover ◽  
Bare Soil ◽  
Energy Balance Model ◽  
Balance Model ◽  
Soil Systems

Comparison between energy balance and mass balance models for actual evapotranspiration assessment

2009 ◽  
Author(s):  
A. Gentile ◽  
L. Pierce ◽  
G. Ciraolo ◽  
G. Zhang ◽  
G. La Loggia ◽  
...  
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Actual Evapotranspiration ◽  
Mass Balance Models
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