Use of optical sensors to monitor  Gaillardia Foug. nitrogen status

Dunn, Bruce L.; Shrestha, Arjina; Goad, Carla L.; Khoddamzadeh, Amir Ali

doi:10.37855/jah.2015.v17i03.34

Cited by 11 publications

(10 citation statements)

References 27 publications

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“…Consequently, the growth and development of seedlings temporarily stagnates and could initially hinder overall plant health [35]. At the 4 WAT sampling period, J. brandegeana was responsive and assimilated N input as indicated by the two sensors chlorophyll index readings [7,16,36,37]. Dunn et al [7] was also in line with the findings of this study, stating that SPAD reading values could differentiate fertilizer treatments clearly as early as 28 days after treatment (DAT).…”

Section: Discussionsupporting

confidence: 86%

“…GreenSeeker TM values revealed lack of significant difference between treatments at 2 WAT (Table 1). This can be attributed to insufficient differences in biomass between plants though all the fertilizer rates received adequate amounts of N [7,16]. At early developmental stages of J. brandegeana, the foliage forming the upper canopy is not completely established.…”

Section: Discussionmentioning

confidence: 99%

“…The GreenSeeker TM was held at 45 cm above the sample plant for each reading [24]. This assured that the field of view for the sensor was~11.85 cm in diameter [16]. In consideration of variation in foliage on the canopy top of each plant, three measurements were taken per replicate in each treatment.…”

Section: Methodsmentioning

confidence: 99%

“…This allows for better understanding of a plant's overall health, vigor and nutrient content at a given time. GreenSeeker TM handheld sensor contains two electroluminescent diodes that emit red (660 nm) and near infrared (NIR) light (770 nm) onto the canopy of the target plant [7,16,17]. Plants with green color exhibit a low reflectance of blue and red, and a high reflectance of NIR radiation [18].…”

mentioning

confidence: 99%

“…Values closer to 1 have a high reflectance of NIR representing a leaf with substantial chlorophyll content, while values closer to 0 represent low chlorophyll content [18].As an addition to GreenSeeker TM readings, Soil Plant Analysis Development (SPAD) meter (Konica Minolta, Ramsey, NJ, USA) was also used to estimate N. The SPAD-502 meter, similar to the GreenSeeker TM , is a non-destructive handheld sensor that gives a numerical representation of the approximate amount of chlorophyll present in a given leaf [17]. The SPAD meter clips onto a single leaf and records light intensity of 650 nm and 940 nm, measuring the absorbance of light emitted [16]. The 650 nm wavelength is correlated to maximum chlorophyll activity while the 940 nm wavelength accounts for other factors including leaf thickness and moisture content [22].…”

mentioning

confidence: 99%

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Precision Agriculture Application for Sustainable Nitrogen Management of Justicia brandegeana Using Optical Sensor Technology

et al. 2019

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Over-fertilization is a common practice in ornamental nursery production. Oftentimes, visual analysis is used to determine plant nutrient levels, leading to less accurate estimates of fertilizer application. This study focused on exploring the suitability of two non-destructive sensors, Soil Plant Analysis Development (SPAD-502) and GreenSeekerTM, for measuring plant tissue nutrient uptake. Florikan Top-Dress fertilizer 12N-6P-8K was applied to Justicia brandegeana in various increments (0, 10, 20, 30, 40, and 50 g) to simulate plants with deficient to excessive nitrogen rates. Various parameters were recorded including Normalized Difference Vegetation Index (NDVI) and SPAD readings, soil leachate analysis (nitrates and phosphate), and total leaf carbon:nitrogen (C:N). The NDVI and SPAD readings were recorded biweekly for three months after the initial controlled release fertilizer (CRF) treatments. Leaf C:N was analyzed through dry combustion while nitrates and phosphate were determined from soil leachate. Results suggest that the smaller amount (20 g) of CRF is as effective in providing N to J. brandegeana as larger amounts (30, 40, 50 g). Implementation of this fertilizer regimen will result in reduced agricultural nutrient runoff and overall negative environmental impacts. Application of optical sensor technology using SPAD and GreenSeekerTM showed promising results in determining the fertilizer requirements of J. brandegeana. This method could serve as a guideline for nursery producers and landscape personnel as a fast and non-destructive tool for sustainable fertilizer management practices within the ornamental plant industry.

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