A digital image-processing-based method for determining the crop coefficient of lettuce crops in the southeast of Spain

Fernández-Pacheco, Daniel G.; Escarabajal-Henarejos, D.; Ruiz-Canales, A.; Conesa, J.; Molina-Martínez, José Miguel

doi:10.1016/j.biosystemseng.2013.07.014

Cited by 51 publications

(32 citation statements)

References 25 publications

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“…This methodology determines the ET as the product of a reference evapotranspiration (ET 0 ) and a crop coefficient (Kc). During the study, the daily crop coefficients (Kc) were calculated using the equations obtained from October to December 2011 by applying the methods proposed by Fernández-Pacheco et al (2014). Initially, an equation that related the values of the PGC, which were obtained by computerized processing of digital images of the vegetation cover and crop height h, were obtained.…”

Section: Methods Of Kc Calibrationmentioning

confidence: 99%

“…1) proposed by Fernández-Pacheco et al (2014). This approach provided, as a first step, the mathematical relationship between the crop height (h) and the percentage of ground cover (PGC) obtained by computer processing of digital images of the crop canopy.…”

Section: Soil Water Balancementioning

confidence: 99%

“…Several authors have achieved satisfactory results relating the PGC with the crop coefficient Kc in tomatoes (Hanson and May, 2006), beans (de Medeiros et al, 2001) and onions (López-Urrea et al, 2009). In lettuce, Fernández-Pacheco et al (2014) developed a new methodology based on digital image processing to estimate the crop coefficient from digital photographs of the vegetation cover. Furthermore, other recent developments have succeeded in relating the fraction of vegetation cover with the root depth (EscarabajalHenarejos et al, 2014).…”

Section: Introductionmentioning

confidence: 95%

“…Methodology proposed by Fernández-Pacheco et al (2014) was used in 2011 to obtain and calibrate equations relating the percentage of green cover, the plant height and the Kc parameter of the studied crop (Fig. 1).…”

Section: Experimental Plotmentioning

confidence: 99%

See 3 more Smart Citations

Digital photography applied to irrigation management of Little Gem lettuce

Escarabajal-Henarejos

Molina-Martínez

Fernández-Pacheco

et al. 2015

Agricultural Water Management

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Section: Methods Of Kc Calibrationmentioning

confidence: 99%

Section: Soil Water Balancementioning

confidence: 99%

Section: Introductionmentioning

confidence: 95%

Section: Experimental Plotmentioning

confidence: 99%

See 2 more Smart Citations

Digital photography applied to irrigation management of Little Gem lettuce

Escarabajal-Henarejos

Molina-Martínez

Fernández-Pacheco

et al. 2015

Agricultural Water Management

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“…This change translated to lower water consumption and a higher dry matter percentage (42,8 %). (Fernández-Pacheco et al, 2014), 0,52 -1,09 for melon (Shukla et al, 2014), 0,82 for caulifl ower and 0,70 for red kale (Sahin et al, 2009). Similarly, López-Urrea et al (2012) found Kc values between 0,60 and 0,75 for Tempranillo vineyards; the lower values were attributed to the component of evaporation from the ground of the ETc after applying water (precipitation or irrigation), which can be high at the beginning of growth when the vegetable cover fraction is at a minimum.…”

Section: Experiments 1 Crop Coeffi Cient Determinationmentioning

confidence: 99%

Basil (Ocimum basilicum L.) water needs calculated from the crop coefficient

et al. 2017

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The determination of the crop coefficient (Kc) throughout the phenological stages is important for the calculation of water requirements of plants. This study determined the Kc curve for Basil (Ocimum basilicum L.) in Candelaria, Valle del Cauca, and evaluated this Kc in greenhouse conditions. Three drainage lysimeters and a portable meteorological station were used to determine the reference evapotranspiration (ETo), which were set up randomly in an experimental plot. The field capacity (FC) moisture content was determined, and the soil moisture and drainage depth were periodically monitored. Daily water balance calculations were conducted to determine the crop's water needs (ETc), and the Kc was calculated based on the quotient between ETc and ETo by performing statistical regression analysis. In the second experiment, in a completely randomized bifactorial design, four treatments were established in Cali (Valle). These treatments were amount of water necessary to maintain the soil moisture at FC and amount of water calculated with the Kc (72 % FC), both treatments with and without fertilizers application. The results showed that the Kc values for basil are: growth stage, 0,45 ± 0,02 (25 days after transplant, dat); maturity stage, 0,59 ± 0,02 (26 -50 dat); and senescence stage, 0,42 ± 0,03 (51 -71 dat). In greenhouse conditions, dry mass percentage, plant height, soil pH and electrical conductivity were similar for both water regimens. The reduction on water with Kc increased the nitrogen foliar but the water use efficient decreased.Keywords: crop coefficient, efficient water management, lysimeter, crop water needs. RESUMENLa determinación del coeficiente del cultivo (Kc) de los estados fenológicos es importante para el cálculo de los requerimientos hídricos de las plantas. Este estudio determinó la curva del Kc para la albahaca (Ocimum basilicum L.) en Candelaria, Valle del Cauca, y evaluó estos Kc en invernadero. Se ubicaron tres lisímetros de drenaje y una estación meteorológica portátil para determinar la evapotranspiración de referencia (ETo), en una parcela experimental. Se determinó la humedad as capacidad de campo (CC) y se monitorearon periódicamente tanto la humedad del suelo como el agua de drenaje. Se realizaron balances hídricos diarios para determinar las necesidades de agua del cultivo (ETc) y el Kc se calculó como el cociente entre ETc y ETo por medio de análisis de regresión. En el segundo experimento se establecieron cuatro tratamientos en un diseño completo al azar en Cali (Valle). Los tratamientos consistieron en evaluar la cantidad de agua calculada a partir de CC y a partir del Kc hallado (72 % de CC), ambos tratamientos con y sin fertilización. Los resultados mostraron que los valores de Kc para cada etapa de albahaca fueron: crecimiento, 0,45 ± 0,02 (25 días después del trasplante, ddt); madurez (0,59 ± 0,02 (26 -50 ddt) y senescencia 0,42 ± 0,03 (51 -71 ddt). En invernadero, el porcentaje de materia seca, altura de planta, pH del suelo y conductividad eléctrica fueron similare...

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An FPGA‐based smart camera for accurate chlorophyll estimations

Pérez-Patricio

Aguilar-González

Camas-Anzueto

et al. 2018

Circuit Theory & Apps

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In this work, a new chlorophyll estimation approach based on the reflectance/ transmittance from the leaf being analyzed is proposed. First, top/underside images from the leaf under analysis are captured, then, the base parameters (reflectance/transmittance) are extracted. Finally, a double-variable linear regression model estimates the chlorophyll content. To estimate the base parameters, a novel optical arrangement is presented. On the other hand, in order to provide a portable device suitable for chlorophyll estimation under large scale food crops, we have implemented our optical arrangement and our algorithmic formulation inside an field-programmable gate array (FPGA)-based smart camera fabric. Experimental results demonstrated that the proposed approach outperforms (in terms of accuracy and processing speed) most previous vision-based approaches, reaching more than 97% accuracy and delivering fast chlorophyll estimations (near 5 ms per estimation).

show abstract

A digital image-processing-based method for determining the crop coefficient of lettuce crops in the southeast of Spain

Cited by 51 publications

References 25 publications

Digital photography applied to irrigation management of Little Gem lettuce

Digital photography applied to irrigation management of Little Gem lettuce

Basil (Ocimum basilicum L.) water needs calculated from the crop coefficient

An FPGA‐based smart camera for accurate chlorophyll estimations

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