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A petiole sap nitrate test for broccoli

Authors :
Aki Kubota
Ronald E. Godin
Thomas A. Doerge
Thomas L. Thompson
Source :
Journal of Plant Nutrition. 20:669-682
Publication Year :
1997
Publisher :
Informa UK Limited, 1997.

Abstract

Nitrogen (N) status of vegetable crops is often monitored by analysis of dried plant tissues. However, dry tissue analysis often causes a significant delay between sampling and analysis. This study was conducted to examine the accuracy of a portable nitrate meter for determining petiole sap nitrate (NO3) contents, and the relationship between NO3‐N concentration in fresh petiole sap and in dried petiole tissue of broccoli grown in southern Arizona during the 1993–94 and 1994–95 winter growing seasons. Experiments were factorial combinations of three irrigation rates and four N rates, both ranging from deficient to excessive. Petioles were sampled throughout each season, and split for sap and dry tissue analysis. A linear correlation was obtained between the two measurements in both seasons, with no consistent effect due to irrigation treatment or crop maturity. The regression coefficients did not differ among seasons. Therefore, a combined regression equation: Y=343+0.047X (r2 = 0.799) was derive...

Details

ISSN :
15324087 and 01904167
Volume :
20
Database :
OpenAIRE
Journal :
Journal of Plant Nutrition
Accession number :
edsair.doi...........6296be52ec1c5a817d3e0e14e74a114d