Petiole nitrate concentration as an indicator of geranium nitrogen status

1983 ◽  
Vol 14 (5) ◽  
pp. 363-371 ◽  
Author(s):  
William R. Woodson ◽  
James W. Boodley
1983 ◽  
Vol 19 (1) ◽  
pp. 103-109 ◽  
Author(s):  
D. M. Oosterhuis ◽  
G. C. Bate

SUMMARYThe possibility of using seasonal changes in leaf nitrate reductase activity (NRA) as a reliable and sensitive indicator of plant nitrogen (N) status has been investigated in field-grown cotton. These changes were compared with those in nitrate concentration in petioles and variations in soil-N concentration. We conclude that NRA in the uppermost, fully-expanded sympodial leaves may provide a more convenient, sensitive and reliable indicator of plant-N status than measurements of nitrate concentrations in petioles.


HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 571b-571 ◽  
Author(s):  
T.K. Hartz ◽  
R.F. Smith ◽  
W.L. Schrader

California vegetable growers are adopting drip irrigation at an accelerating pace, which affords the opportunity for more exacting control of nitrogen nutrition. Consequently, the need for quick, accurate, grower-friendly techniques for monitoring nitrogen status in soil and plant material has increased. Three field monitoring techniques were examined in detail: the analysis of soil water samples drawn by soil solution access tubes (SSAT). leaf reflectance as measured by the Minolta SPAD 502 chlorophyll meter, and petiole sap analysis with a Horiba portable nitrate-selective electrode meter. Nitrate concentration in soil solution was highly stratified in drip-irrigated soils, both with regard to location in the field and position with respect to the drip line, making the use of SSAT technology impractical as a tool for routine N fertigation scheduling. Correlation of SSAT nitrate values to any measure of plant N status was poor. Similarly, leaf reflectance correlated poorly with any measure of tissue N in the crops examined. Nitrate content of petiole sap was highly correlated with conventional laboratory analysis of dry petiole tissue over a range of crops and nitrogen levels.


1968 ◽  
Vol 71 (3) ◽  
pp. 383-392 ◽  
Author(s):  
P. J. Last ◽  
P. B. H. Tinker

SUMMARYThe use of the correct N dressing for beet is important, as any excess decreases juice purity and profit, and may decrease sugar yield, but no analytical method will at present predict the best dressing in any particular field. The concentration of nitrate in leaves and petioles of beet was determined to test if it would determine the need for top-dressings of N. Beet on seventeen field trials in 3 years testing N were sampled. Nitrate in a wet tissue extract was determined by reducing to ammonia with titanous sulphate and subsequent distillation.The petiole nitrate concentration decreased sharply with time, from around 1000 ppm in wet tissue in early June to less than 100 ppm in early September. The nitrate concentrations were closely related to nitrogen dressing, and the rapid decline in concentration was decreased by top-dressings. Comparison of samples taken in June showed that most of the variation between the experiments could be accounted for by the different ages of the plants. Sodium fertilizer had no effect on nitrate content.Petiole nitrate was inversely related to juice purity and sugar concentration, especially when the nitrate content exceeded 700 ppm in June.On average, petiole nitrate concentrations about 800 ppm in June were associated with the largest sugar yields, but the content could not be used to predict nitrogen top-dressing requirement accurately at individual sites.Measuring NO3-N cannot at present be recommended as a method for deciding how much nitrogen fertilizer to use, but it has value for detecting severe deficiencies and in research.


2021 ◽  
Vol 285 ◽  
pp. 110157
Author(s):  
Alejandra Rodríguez ◽  
M. Teresa Peña-Fleitas ◽  
Francisco M. Padilla ◽  
Marisa Gallardo ◽  
Rodney B. Thompson

1985 ◽  
Vol 25 (1) ◽  
pp. 231 ◽  
Author(s):  
J.B Robinson ◽  
M.G McCarthy

Summary. A study of the petiole nutrient status of cvv. Shiraz, Cabernet Sauvignon and Rhine Riesling (Vitis vinifera) was carried out in 19 vineyards of each in the Barossa Valley, South Australia, during 1979 to 1982. The sampling unit chosen was the petiole of leaves opposite bunches, collected at flowering time. Nitrogen status (assessed as nitrate concentration) varied widely among vineyards and high concentrations of nitrate could be associated with use of organic materials (chicken litter, winery marc) in the vineyards. Phosphorus status was almost invariably higher than necessary. Potassium, magnesium and chloride status were usually high by Californian standards. Of the trace elements, boron was low in 1979 to 1980 in some vineyards, but sufficient in other years. Zinc and manganese were usually present in sufficient quantities. Daily sampling of petioles showed that nutrient levels during the flowering period changed less dramatically in this region than in California. Pre-bloom foliar sprays ofurea with zinc had non-significant effects on petiole nitrate concentration. Differences in nutrient concentrations between the three cultivars were detected in some years. The standards used to interpret petiole analysis data in California, while useful in the survey area, required some modification for local use, and working standards are proposed.


2003 ◽  
Vol 80 (4) ◽  
pp. 251-261 ◽  
Author(s):  
G. Bélanger ◽  
J. R. Walsh ◽  
J. E. Richards ◽  
P. H. Milburn ◽  
N. Ziadi

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