Evaluation of Absolute Measurements and Normalized Indices of Proximal Optical Sensors as Estimators of Yield in Muskmelon and Sweet Pepper
-
Published:2023-04-20
Issue:8
Volume:15
Page:2174
-
ISSN:2072-4292
-
Container-title:Remote Sensing
-
language:en
-
Short-container-title:Remote Sensing
Author:
Karaca Cihan12ORCID, Thompson Rodney B.23ORCID, Peña-Fleitas M. Teresa23, Gallardo Marisa23, Padilla Francisco M.23ORCID
Affiliation:
1. Department of Greenhouse Production, Kumluca Vocational School, Akdeniz University, Antalya 07059, Türkiye 2. Department of Agronomy, University of Almeria, 04120 Almeria, Spain 3. CIAIMBITAL Research Centre for Mediterranean Intensive Agrosystems and Agrifood Biotechnology, University of Almeria, 04120 Almeria, Spain
Abstract
The generally established protocol for leaf measurement with proximal optical sensors is to use the most recently fully expanded leaf. However, differences in the nitrogen (N) status of lower and upper leaves could possibly be used to enhance optical sensor measurement. Normalized indices that consider both upper and lower leaves have been proposed to improve the assessment of crop N status and yield estimation. This study evaluated whether normalized indices improved the estimation of crop yield from measurements with three different proximal optical sensors: (i) SPAD-502 leaf chlorophyll meter, (ii) Crop Circle ACS 470 canopy reflectance sensor, and (iii) Multiplex fluorescence meter. The study was conducted with sweet pepper (Capsicum annuum L.) and muskmelon (Cucumis melo L.) in plastic greenhouses in Almeria, Spain. Measurements were made on the latest (most recent) leaf (L1), and the second (L2), third (L3) and fourth (L4) fully expanded leaves. Yield estimation models, using linear regression analysis, were developed and validated from the absolute and normalized measurements of the three optical sensors. Overall, the calibration and validation results indicated that the absolute measurements generally had better yield estimation performance than the normalized indices for all the leaves and different leaf profiles. In both species, there was a better performance at the early phenological stages, such as the vegetative and flowering stages, for the absolute and normalized indices for the three optical sensors. Absolute proximal optical sensor measurements on the lower leaves (L2, L3 and L4) slightly improved yield estimation compared to the L1 leaf. Normalized indices that included the L4 leaf (L1–L4) had better yield estimation compared to those using L2 and L3 (e.g., L1–L2 and L1–L3). Of the normalized indices evaluated, the yield performance of the Relative Index (RI), Relative Difference Index (RDI), and Normalized Difference Index (NDI) were very similar, and generally superior to the Difference Index (DI). Overall, the results of this study demonstrated that for three different proximal optical sensors in both muskmelon and sweet pepper (i) normalized indices did not improve yield estimation, and (ii) that absolute measurements on lower leaves (L2, L3 and L4) slightly improved yield estimation performance.
Funder
Spanish Ministry of Science, Innovation and University Ramón y Cajal grant Scientific and Technological Research Council of Turkey
Subject
General Earth and Planetary Sciences
Reference50 articles.
1. SPAD Values and Nitrogen Nutrition Index for the Evaluation of Rice Nitrogen Status;Yang;Plant Prod. Sci.,2014 2. de Souza, R., Grasso, R., Peña-Fleitas, M.T., Gallardo, M., Thompson, R.B., and Padilla, F.M. (2020). Effect of Cultivar on Chlorophyll Meter and Canopy Reflectance Measurements in Cucumber. Sensors, 20. 3. Diagnosis Tool for Plant and Crop N Status in Vegetative Stage. Theory and Practices for Crop N Management;Lemaire;Eur. J. Agron.,2008 4. Tei, F., Nicola, S., and Benincasa, P. (2017). Advances in Research on Fertilization Management in Vegetable Crops, Springer. 5. Padilla, F.M., Gallardo, M., Peña-Fleitas, M.T., de Souza, R., and Thompson, R.B. (2018). Proximal Optical Sensors for Nitrogen Management of Vegetable Crops: A Review. Sensors, 18.
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献
|
|