Effect of Nitrogen and Trinexapac-Ethyl Rates on the SPAD Index of Wheat Leaves |
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Authors: | Marcelo Curitiba Espindula Valterley Soares Rocha Paulo Cezar Rezende Fontes Raul Carvalho Corrêa da Silva Leandro Torres de Souza |
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Institution: | Departamento de Fitotecnia , Universidade Federal de Vi?osa , Minas Gerais, Brazil |
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Abstract: | ABSTRACT The objective of this study was to evaluate the effect of nitrogen (N) and trinexapac-ethyl (TE) rates on the SPAD index in wheat flag leaf. The treatments were five N rates (30, 60, 90, 120, 150 kg ha?1) combined with four TE rates (0, 63, 125, 188 g ha?1). The experiment was carried out in a randomized block design with four repetitions. SPAD index, leaf N content and grain yield showed quadratic response to the increase in N rates, whereas area, wet and dry weight of flag leaf presented linear increase. TE caused linear increase in SPAD index, linear decrease in leaf area, reduction in grain yield with smaller N rates and increase with larger N rates. The N content, and the wet and dry weight of flag leaf were not affected by TE. SPAD calibration to estimate N status in wheat should be specific for each TE rate. |
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Keywords: | Triticum aestivum diagnosis chlorophyll green |
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