Research and Application of Non-Destructive Testing Diagnosis Technology of Tomato

Wu, Xin‐Yan; Guo, Jianhua; Zhao, Chunjiang; Chen, Liping; Zhang, Yigong; Fang, Zheng; Yang, Yue

doi:10.1166/sl.2012.1889

Cited by 8 publications

(7 citation statements)

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“…For processing tomato, Farneselli et al () reported generally good linear relationships between SPAD measurements and total above‐ground plant N content, but that the nature and strength of the relationships varied with the day of measurement. For indeterminate tomato, Wu et al () reported that SPAD measurements of chlorophyll content were highly related to leaf N content in each of the individual growth stages of establishment, flowering, fruiting and following fruiting.…”

Section: Discussionmentioning

confidence: 99%

“…This is important where N is applied throughout the crop, as occurs with combined drip irrigation and fertigation systems. Some studies of optical sensors with tomato were limited to measurements made on a single day (Güler & Büyük, ) or several individual days (Wu et al , ). There are very few reports of the use of optical sensors with indeterminate tomato for fresh consumption, despite it being an important crop.…”

Section: Introductionmentioning

confidence: 99%

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Threshold values of canopy reflectance indices and chlorophyll meter readings for optimal nitrogen nutrition of tomato

et al. 2014

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Sustainable and optimal economic N management requires correct and timely on-farm assessment of crop N status to detect N deficiency or excess. Optical sensors are promising tools to assess crop N status throughout a crop or at critical times. The ability of optical sensor measurements of canopy reflectance (Crop Circle ACS 470) and leaf chlorophyll (SPAD 502 chlorophyll meter) to assess crop N status was evaluated weekly throughout an indeterminate tomato crop. Strong linear relationships with the optical sensor measurements were obtained, throughout most of the crop, for both (a) crop N content for ranges of 1.5-4.5%, and (b) the nitrogen nutrition index (NNI) for ranges of 0.4-1.3. The relationships of the optical sensor measurements to crop NNI were generally equal to or slightly better than with crop N content. Indices based on reflectance in the red, the normalised difference vegetation index (NDVI) and the red vegetation index (RVI), were the best predictors of crop N status in terms of goodness of fit, earliness and maintenance of relationships throughout the crop. SPAD chlorophyll readings and reflectance indices based on reflectance in the green, the normalised difference vegetation index on greenness (GNDVI) and the green vegetation index (GVI), were good indicators of crop N status for most of the crop, but with lower goodness of fit in the latter part of the crop. The linear relationships between sensor indices and readings with NNI or crop N content, each week, demonstrated the potential for using proximal canopy reflectance indices such as NDVI and RVI, and chlorophyll meter for monitoring crop N status of indeterminate tomato crops. Threshold values for optimal crop N nutrition for canopy reflectance indices and for chlorophyll meter readings were derived for each day of measurement from the relationships between optical sensor measurements and NNI by solving for NNI = 1. The threshold values obtained for each index and type of measurement varied during the crop cycle. The approach developed for determining threshold values from NNI can facilitate on-farm use of optical sensors for monitoring crop N status, by enabling assessment of whether crop N status is excessive, deficient or adequate.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Threshold values of canopy reflectance indices and chlorophyll meter readings for optimal nitrogen nutrition of tomato

et al. 2014

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“…Chlorophyll meters have been successfully used to assess crop N status of vegetable crops in numerous studies with species, such as fresh tomato [ 55 , 72 ], processing tomato [ 68 , 73 ], muskmelon [ 58 ], cucumber [ 59 ], sweet pepper [ 42 ], or potato [ 53 , 54 ].…”

Section: Chlorophyll Metersmentioning

confidence: 99%

“…The NNI is an effective and established indicator of crop N status [ 12 ], calculated as the ratio between actual crop N content and the critical crop N content, i.e., the minimum N content necessary to achieve maximum growth of a crop [ 76 ]. Similarly, strong relationships between SPAD measurements and crop and leaf N content were found in individual phenological phases of the tomato [ 72 , 77 ]. Contrasting results to those mentioned both for processing and fresh-consumption tomatoes were found by Ulissi et al [ 78 ] in the processing tomato, where weak relationships between SPAD values and plant N content were likely caused by the narrow range of plant N contents evaluated.…”

Section: Chlorophyll Metersmentioning

confidence: 99%

Proximal Optical Sensors for Nitrogen Management of Vegetable Crops: A Review

Padilla

Gallardo

Peña-Fleitas

et al. 2018

Sensors

149

130

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Optimal nitrogen (N) management is essential for profitable vegetable crop production and to minimize N losses to the environment that are a consequence of an excessive N supply. Proximal optical sensors placed in contact with or close to the crop can provide a rapid assessment of a crop N status. Three types of proximal optical sensors (chlorophyll meters, canopy reflectance sensors, and fluorescence-based flavonols meters) for monitoring the crop N status of vegetable crops are reviewed, addressing practical caveats and sampling considerations and evaluating the practical use of these sensors for crop N management. Research over recent decades has shown strong relationships between optical sensor measurements, and different measures of crop N status and of yield of vegetable species. However, the availability of both: (a) Sufficiency values to assess crop N status and (b) algorithms to translate sensor measurements into N fertilizer recommendations are limited for vegetable crops. Optical sensors have potential for N management of vegetable crops. However, research should go beyond merely diagnosing crop N status. Research should now focus on the determination of practical fertilization recommendations. It is envisaged that the increasing environmental and societal pressure on sustainable crop N management will stimulate progress in this area.

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“…The use of CMs to assess crop N status has been the subject of a large body of research since the 1980s ( Padilla et al, 2018 ). Overall, CM measurements have been shown to be strongly related to leaf and crop N content in a wide range of crops, such as cereals ( Arregui et al, 2006 ; Zhao et al, 2018 ), tubers ( Olivier et al, 2006 ), vegetables ( Wu et al, 2012 ; Padilla et al, 2015 , 2018 ) and ornamentals ( Basyouni et al, 2015 ; Dunn et al, 2018 ). Most research with CMs has been conducted with transmittance-based CMs ( Fox and Walthall, 2008 ), but recently, there has been increasing research activity with fluorescence-based CMs ( Tremblay et al, 2012 ; Agati et al, 2013 ; Padilla et al, 2016 ).…”

Section: Introductionmentioning

confidence: 99%

Different Responses of Various Chlorophyll Meters to Increasing Nitrogen Supply in Sweet Pepper

et al. 2018

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Intensive vegetable production is commonly associated with excessive nitrogen (N) fertilization and associated environmental problems. Monitoring of crop N status can enhance crop N management. Chlorophyll meters (CMs) could be used to monitor crop N status because leaf chlorophyll (chl) content is strongly related to crop N status. To monitor crop N status, relationships between CM measurements and leaf chl content require evaluation, particularly when excessive N is supplied. The SPAD-502 meter, atLEAF+ sensor, MC-100 Chlorophyll Concentration Meter, and Multiplex sensor were evaluated in sweet pepper with different N supply, throughout the crop, ranging from very deficient to very excessive. CM measurements of all sensors and indices were strongly and positively related to leaf chlorophyll a + b content with curvilinear relationships over the entire range of chl measured (∼0–80 μg cm-2). Measurements with the SPAD-502, and atLEAF+, and of the Multiplex’s simple fluorescence ratio index (SFR) had asymptotic responses to increasing leaf chl. In contrast, the MC-100’s chlorophyll content index (CCI) had a progressively increasing response. At higher chlorophyll a + b contents (e.g., >40 μg cm-2), SPAD-502, atLEAF+ and SFR measurements tended to saturate, which did not occur with CCI. Leaf chl content was most accurately estimated by CCI (R2 = 0.87), followed by the SPAD-502 meter (R2 = 0.85). The atLEAF+ sensor was the least accurate (R2 = 0.76). For leaf chl estimation, CCI measured with the MC-100 meter was the most effective of the four sensors examined because it: (1) most accurately estimated leaf chl content, and (2) had no saturation response at higher leaf chl content. For non-saturating leaf chl content (∼0–40 μg cm-2), all indices were sensitive indicators. As excessive applications of N are frequent in intensive vegetable crop production, the capacity of measuring high leaf chl contents without a saturation response is an important consideration for the practical use of chlorophyll meters.

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Research and Application of Non-Destructive Testing Diagnosis Technology of Tomato

Cited by 8 publications

References 1 publication

Threshold values of canopy reflectance indices and chlorophyll meter readings for optimal nitrogen nutrition of tomato

Threshold values of canopy reflectance indices and chlorophyll meter readings for optimal nitrogen nutrition of tomato

Proximal Optical Sensors for Nitrogen Management of Vegetable Crops: A Review

Different Responses of Various Chlorophyll Meters to Increasing Nitrogen Supply in Sweet Pepper

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