Efficiency of portable chlorophyll meters in assessing the nutritional status of wheat plants

Alessana F Schlichting,William Pietro-Souza,Tonny J A Da Silva,Edna M Bonfim-Silva,Lorraine Do N Farias,Matheus De C Silva

doi:10.1590/1807-1929/agriambi.v19n12p1148-1151

Alessana F Schlichting, William Pietro-Souza + Show 4 more

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https://doi.org/10.1590/1807-1929/agriambi.v19n12p1148-1151

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Abstract

ABSTRACT The objective of this study was to verify the efficiency of two portable chlorophyll meters (Minolta SPAD® 502 and Falker ClorofiLOG® 1030) in assessing the nutritional status of wheat plants, correlating the indices from the devices and the direct determination of chlorophyll content with the concentration of nitrogen (N) in the plant. The experiment was conducted in a greenhouse, in pots with 5 dm3 of Oxisol, in a completely randomized design, with six N doses (0, 80, 160, 240, 320 and 400 mg dm-3) and five replicates. At 47 days after emergence, the readings of SPAD and Falker indices and the quantification of chlorophyll content and N concentration in wheat plants were performed, as well as analysis of variance and correlation test, both at 0.05 probability level. The chlorophyll meters Minolta SPAD® 502 and Falker ClorofiLOG® 1030 do not differ with respect to the indirect determination of chlorophyll in wheat plants. The Falker chlorophyll index was statistically equal to the chlorophyll content. Indirect chlorophyll indices and chlorophyll content showed a high correlation with the N concentration in the plant.

Highlights

Nitrogen (N) is considered as one of the most important nutrients in plant nutrition, since it is used in the synthesis of cell compounds, such as chlorophyll (Lima et al, 2001), influencing photosynthesis, production and transport of photoassimilates, growth rate between leaves and roots and the formation of roots (Taiz & Zieger, 2004)
The evaluated methods of chlorophyll measurement using the portable devices SPAD® 502 and Falker ClorofiLOG® 1030 in wheat plants showed the same efficiency (p ≥ 0.01) with respect to the reading of chlorophyll index. When these methods were compared with the laboratory quantification of chlorophyll contents, only the Falker index was significantly efficient (p ≤ 0.01) (Table 1)
The response is the same when the Falker chlorophyll meter was sued, because this device showed indices statistically equal to the chlorophyll contents measured at the laboratory, which shows the capacity of variation of chlorophyll indices, according to the nutritional status of wheat plants

Summary

Introduction

Nitrogen (N) is considered as one of the most important nutrients in plant nutrition, since it is used in the synthesis of cell compounds, such as chlorophyll (Lima et al, 2001), influencing photosynthesis, production and transport of photoassimilates, growth rate between leaves and roots and the formation of roots (Taiz & Zieger, 2004). The state of Mato Grosso, in order to increase its agricultural diversity, has expanded wheat-planted areas every year and increased its production in the Cerrado (CONAB, 2013). Pietro-Souza et al (2013) observed that N fertilization positively influences the initial development of wheat plants cultivated in a Red Latosol in the Cerrado region. Practical and fast evaluation methods that allow assessing plant nutritional status become essential to facilitate crop management. Portable leaf chlorophyll meters, or chlorophyll meters, are widely used, since they estimate chlorophyll contents in an instantaneous, indirect and nondestructive way, based on the optical properties of the leaves, constituting an alternative for the evaluation of N concentration in plants (Argenta et al, 2001)

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