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L.E. Parent and M. Dafir

Abbreviations: CDA, compositional data analysis; CND, compositional nutrient diagnosis; CVA, critical value approach; DRIS, diagnosis and recommendation integrated system. 1 Professor. 2 Graduate student. The research was supported by the Natural

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Han Xu, Cuihua Bai, Wei Wang, Changmin Zhou, Luwei Zhu, and Lixian Yao

). Foliar nutrient diagnosis has been developed and used in crops for decades, targeting to assess plant nutritional status and adjust nutrient management to promote crop productivity ( Amundson and Koehler, 1987 ; Rubio-Covarrubias et al., 2009 ). Foliar

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Alfonso Llanderal, María Teresa Lao, Juana Isabel Contreras, and María Luz Segura

) and the highest were Mg/K for MT (62%) and P/Mg for HV (66%). Table 2. Diagnosis and recommendation integrated system norms in different phenological stages. Means with different letters in the same row indicate significant differences between the

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L.E. Parent, D. Isfan, N. Tremblay, and A. Karam

Compositional nutrient diagnosis (CND) provides undistorted (linearized) variates amenable to principal component analysis (PCA) using a row-centered logratio transformation of foliar nutrient data. Our objectives were to carry PCA on raw or transformed nutrient data for carrot (Daucus carota L.) crops and to compare the critical value approach (CVA), diagnosis and recommendation integrated system (DRIS), and CND diagnoses using independent data. PCA conducted on percentage or log-transformed data produced similar multivariate structures difficult to interpret. PCA conducted on DRIS indexes and on row-centered logratios produced PCs (K-Ca+), (N+K-Ca-Mg+), and (P-Mg+) and PCs (K-Mg+), (N-Ca+), and (P-), respectively. Nutrient contrasts were easiest to interpret with CND and reflected either K-Mg antagonism or N dilution and Ca accumulation over time. CVA diagnosis of independent samples was generally not in line with DRIS or CND. DRIS and CND diagnostic indexes were highly correlated (r = 0.98 to 0.99). By summing bivariate DRIS functions, the DRIS index calculation procedure effectively row-centered the nutrient values for carrots. DRIS and CND index diagnosis indicated treatment-dependent Ca shortage. In contrast, CND PC diagnosis indicated overall stationary values for PC (N-Ca+) whatever treatment was applied. CND PC diagnosis is a multivariate (PCA) approach providing simplified computational effort and a theoretical basis for further improvements in foliar diagnosis.

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Thomas G. Bottoms, Mark P. Bolda, Mark L. Gaskell, and Timothy K. Hartz

Miner (2000) . Conversely, the DRIS P and K ranges were higher than established standards, undoubtedly due to the high soil availability of these nutrients and high fertilization rates. Table 2. Comparison between diagnosis and recommendation integrated

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L.E. Parent, A. Karam, and S.A. Visser

Compositional nutrient diagnosis (CND) norms were computed from a diagnosis and recommendation integrated system (DRIS) databank as means and sds of CND multinutrient ratios and CND factors characterizing the high-yielding subpopulation of greenhouse tomato (Lycopersicon esculentum Mill.) plants during the 3- to. 8-cluster developmental stages. A CND multinutrient ratio is a row-centered logratio corrected for the bounded-sum constraint to 100% of all components, including a filling value between known components and 100%. CND multinutrient ratios for N, P, K, Ca, and Mg were reduced to three dimensions by principal component analysis (PCA). Varimax-rotated factors–(N-K-Ca+), (Ca+Mg-), and (P)—were designated as contrasts describing nutrient status and equilibria in diagnostic tissues. CND nutrient indexes for N, P, K, Ca, and Mg were highly correlated with their DRIS counterparts (r = 0.964 to 0.987), using 20 independent observations. Since CND is compatible with PCA, CND could expand DRIS to a multivariate diagnostic approach projecting structured information on nutrient data into a Euclidean space. A critical sphere specific to a developmental stage could delineate the high-yielding subpopulation for diagnostic purposes. The critical radius defined using a probabilistic approach to capture the high yielders should be validated with independent fertilizer experiments.

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Alireza Pourreza, Won Suk Lee, Mark A. Ritenour, and Pamela Roberts

first and last repetitions for each class. All data analyses were conducted using MATLAB (version R2011a; MathWorks, Natick, MA). Band selection. To determine the most important wavelengths in CBS diagnosis, five feature ranking methods including t

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Adou Rahim Alimi Assimiou and Léon E. Parent

In Quebec, potato crops are largely grown on light acid soils altered by podzolization. In the plow layer, abundance of sesquioxides, low pH and low organic matter content produce high P-fixing capacity. Liming to pH not exceeding 5.6, organic matter additions and banding of P fertilizers are practices to improve the P status in the soil–plant system. Plant response to treatments could be diagnosed by yield evaluation and foliar analysis. Agricultural lime, dolomitic limestone and basalt were applied to an acid soil (pH 4.6). Ordinary superphosphate, biosuperphosphate, triple superphosphate, and diammonium phosphate impregnated with humic peat were banded at two rates. Highest tuber yield was 40 t·ha–1. There was no response to liming materials as pH did not exceed 4.9. There was a significant response to P fertilizers. Nutrient balance assessment of the foliage by Compositional Nutrient Diagnosis indicated a critical “d” value of 1.5 and a critical P index of 0.8.

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Michael B. Thomas, Jonathan H. Crane, James J. Ferguson, Howard W. Beck, and Joseph W. Noling

The TFRUIT·Xpert and CIT·Xpert computerbased diagnostic programs can quickly assist commercial producers, extension agents, and homeowners in the diagnosis of diseases, insect pest problems and physiological disorders. The CIT·Xpert system focuses on citrus (Citrus spp.), whereas the TFRUIT·Xpert system focuses on avocado (Persea americana Mill.), carambola (Averrhoa carambola L.), lychee (Litchi chinensis Sonn.), mango (Mangifera indica L.), papaya (Carica papaya L.), and `Tahiti' lime (Citrus latifolia Tan.). The systems were developed in cooperation with research and extension specialists with expertise in the area of diagnosing diseases, disorders, and pest problems of citrus and tropical fruit. The systems' methodology reproduces the diagnostic reasoning process of these experts. Reviews of extension and research literature and 35-mm color slide images were completed to obtain representative information and slide images illustrative of diseases, disorders, and pest problems specific to Florida. The diagnostic programs operate under Microsoft-Windows. Full-screen color images are linked to symptoms (87 for CIT·Xpert and 167 for TFRUIT·Xpert) of diseases, disorders, and insect pest problems of citrus and tropical fruit, respectively. Users can also refer to summary documents and retrieve management information from the Univ. of Florida's Institute of Food and Agricultural Sciences extension publications through hypertext links. The programs are available separately on CD-ROM and each contains over 150 digital color images of symptoms.

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Nicolas Tremblay and Léon-Étienne Parent

Celery (Apium graveolens var. Dulce) is a species particularly sensitive to nutritional balance. Seedlings in multicellular trays sometimes present problems that can be traced to nutritional causes. DRIS (Diagnosis and Recommendation Integrated System) and CND (Compositional Nutrient Diagnosis) are two recent concepts that can be implemented to diagnose nutritional imbalances from tissue analyses of any plant species. A data bank of 215 observations was used to elaborate DRIS and CND norms for celery transplants. The threshold yield for high yielders was set at 1600 g/plant (27% of the population). Both DRIS and CND systems were implemented and a validation process was undertaken. Nutrient deficiencies (N, P, K, Ca, Mg, Fe, B and Zn) were induced on celery seedlings in growing chambers. Tissues samples were given a balanced fertilization. The diagnosing methods (DRIS and CND) were compared on the basis of their ability to identify correctly the induced nutrient deficiencies.