Critical petiole nitrate concentration of two processing potato cultivars in Eastern Canada

2003 ◽  
Vol 80 (4) ◽  
pp. 251-261 ◽  
Author(s):  
G. Bélanger ◽  
J. R. Walsh ◽  
J. E. Richards ◽  
P. H. Milburn ◽  
N. Ziadi
Keyword(s):  
Nitrate Concentration ◽  
Potato Cultivars ◽  
Eastern Canada ◽  
Petiole Nitrate Concentration

Nitrogen Uptake of Field-grown Cotton. II. Nitrate Reductase Activity and Petiole Nitrate Concentration as Indicators of Plant Nitrogen Status

1983 ◽  
Vol 19 (1) ◽  
pp. 103-109 ◽  
Author(s):  
D. M. Oosterhuis ◽  
G. C. Bate
Keyword(s):  
Nitrate Reductase ◽  
Seasonal Changes ◽  
Nitrate Reductase Activity ◽  
Nitrate Concentration ◽  
Reductase Activity ◽  
Soil N ◽  
Plant Nitrogen ◽  
Petiole Nitrate Concentration ◽  
Leaf Nitrate ◽  
N Status

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.

COMPARISON OF SPAD CHLOROPHYLL METER READINGS vs. PETIOLE NITRATE CONCENTRATION IN SUGARBEET

2002 ◽  
Vol 25 (9) ◽  
pp. 1975-1986 ◽  
Author(s):  
Peter Sexton ◽  
Jim Carroll
Keyword(s):  
Nitrate Concentration ◽  
Chlorophyll Meter ◽  
Petiole Nitrate Concentration

Nitrate nitrogen in leaves and petioles of sugar beet in relation to yield of sugar and juice purity

1968 ◽  
Vol 71 (3) ◽  
pp. 383-392 ◽  
Author(s):  
P. J. Last ◽  
P. B. H. Tinker
Keyword(s):  
Sugar Beet ◽  
Nitrogen Fertilizer ◽  
Analytical Method ◽  
Nitrate Nitrogen ◽  
Nitrate Concentration ◽  
Field Trials ◽  
Nitrate Content ◽  
Rapid Decline ◽  
Nitrate Concentrations ◽  
Petiole Nitrate Concentration

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.

Use of petiole analysis for assessment of vineyard nutrient status in the Barossa district of South Australia

1985 ◽  
Vol 25 (1) ◽  
pp. 231 ◽  
Author(s):  
J.B Robinson ◽  
M.G McCarthy
Keyword(s):  
Nitrate Concentration ◽  
South Australia ◽  
Nutrient Status ◽  
Analysis Data ◽  
Nutrient Concentrations ◽  
Chicken Litter ◽  
Daily Sampling ◽  
High Concentrations ◽  
Petiole Nitrate Concentration ◽  
Local Use

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.

The relationship between crop yield and petiole nitrate concentration at various growth stages

1977 ◽  
Vol 46 (3) ◽  
pp. 705-712 ◽  
Author(s):  
M. A. Scaife ◽  
A. Barnes
Keyword(s):  
Crop Yield ◽  
Nitrate Concentration ◽  
Growth Stages ◽  
Petiole Nitrate Concentration ◽  
The Relationship

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
Keyword(s):  
Nitrate Concentration ◽  
Nitrogen Status ◽  
Petiole Nitrate Concentration

Seasonal diving and foraging behaviour of Eastern Canada-West Greenland bowhead whales

2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  
Keyword(s):  
Climate Change ◽  
Late Summer ◽  
Calanoid Copepods ◽  
Eastern Canada ◽  
West Greenland ◽  
Bowhead Whales ◽  
Seasonal Movement ◽  
Dive Behaviour ◽  
Calanus Glacialis ◽  
Canada West

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.

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