PERFORMANCE OF DUALEX IN SPRING WHEAT FOR CROP NITROGEN STATUS ASSESSMENT,YIELD PREDICTION AND ESTIMATION OF SOIL NITRATE CONTENT |
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Authors: | Nicolas Tremblay Zhijie Wang Carl Bélec |
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Institution: | Agriculture and Agri-Food Canada , Saint-Jean-sur-Richelieu , Quebec , Canada |
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Abstract: | Dualex and SPAD are devices developed for the purpose of testing crop nitrogen (N) status. These instruments were used in a wheat experiment in order to compare their respective performance in assessing leaf nitrogen (N) concentration, response to N topdressing application, soil nitrate (NO3)-N levels and in predicting grain yield. The experiment included different N rates in 2005 and 2006 in the Montérégie region of Quebec, Canada. Dualex readings correlated negatively with SPAD readings, leaf N concentration, soil NO3-N content and wheat grain yield. SPAD alone and the ratio of SPAD to Dualex measurements (Chl/Phen) were linearly related to N application rate but no effect of N application rate was found for individual Dualex parameters. However, both SPAD and Dualex readings were affected by year effects. The Dualex was also capable of indirect evaluation of in-season soil NO3-N accumulation and the prediction of wheat yield, but more so as Chl/Phen. |
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Keywords: | SPAD Dualex nitrogen status soil NO3-N grain yield |
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