Determination of critical nitrogen concentrations of lettuce (Lactuca sativa L. cv. Montello) grown in sand culture

1992 ◽  
Vol 32 (6) ◽  
pp. 759 ◽  
Author(s):  
DO Huett ◽  
E White
Keyword(s):  
Dry Matter ◽  
Growth Period ◽  
Sand Culture ◽  
N Application ◽  
Total N ◽  
N Supply ◽  
Nitrate N ◽  
N Concentration ◽  
Nitrate Concentrations ◽  
Petiole Sap

A gamma x cubic response surface model was used to predict the dry matter yield of lettuce cv. Montello over the 8-week growth period in sand culture with nitrogen (N) levels of 2, 5, 11, 18 and 36 mmol/L. At 1, 2, 3, 5, 7 and 8 weeks after transplanting, dry matter yield relative to maximum was plotted against tissue N concentration to derive diagnostic concentrations of petiole sap nitrate-N and leaf total N in youngest fully opened leaf (YFOL), youngest fully expanded leaf (YFEL) and oldest green leaf (OL), and total N in bulked leaf samples. Critical concentrations corresponding to 90% maximum yield are presented. Growth was consistently depressed at 2 mmol N/L due to N deficiency, and at 36 mmol N/L due to salt toxicity. Petiole sap nitrate concentrations were more responsive than leaf total N concentrations to N application levels. Leaf N concentrations at N application levels of 18 and 36 mmol/L were often similar. Critical leaf total N concentrations in YFOL and YFEL decreased from 2 weeks after transplanting to maturity, whereas the opposite trend occurred for petiole sap nitrate concentrations. Critical total N concentration ranges in YFEL were 0.30-0.95 g/L for petiole sap nitrate-N, and 4.00-5.30% for leaf total N concentration. Critical leaf total N and petiole sap nitrate concentrations clearly differentiated between inadequate and adequate N application rates. Critical values in most cases, differentiated toxic concentrations. Nitrogen application levels of 2 and 36 mmol N/L reduced (P<0.05) potassium, calcium and magnesium concentrations in all leaves. This confirms the importance of optimising N supply when determining critical levels of these nutrients for lettuce. Petiole sap nitrate-N concentrations, which can be determined rapidly in the field, can be used to distinguish between a deficient and an adequate N supply. The marked increase in critical concentration over the growth period requires consecutive determinations to verify the N status of lettuce.

Determination of critical nitrogen concentrations of potato (Solanum tuberosum L. cv. Sebago) grown in sand culture

1992 ◽  
Vol 32 (6) ◽  
pp. 765 ◽  
Author(s):  
DO Huett ◽  
E White
Keyword(s):  
Dry Matter ◽  
Maximum Yield ◽  
Growth Period ◽  
Sand Culture ◽  
N Application ◽  
Total N ◽  
Nitrate N ◽  
Nitrate Concentrations ◽  
Petiole Sap ◽  
Leaf Nitrate

A gamma x cubic response surface model was used to predict the dry matter yield of potato cv. Sebago over the 12-week growth period in sand culture with nitrogen (N) levels of 2, 7, 14, 29 and 43 mmol N/L. At each 2-week sampling period after emergence, dry matter yield relative to maximum was plotted against tissue N concentration to derive diagnostic petiole, petiole sap, leaf nitrate-N and leaf total N in youngest fully opened leaf (YFOL), youngest fully expanded leaf (YFEL) and oldest green leaf (OL) and for total N in bulked leaves. Critical concentrations corresponding to 90% maximum yield are presented. Tissue nitrate was much more responsive than leaf total N to applied N over the 2-14 mmol/L range where positive growth responses to N were recorded. Plants grown with 2 mmol N/L were severely N deficient and growth was depressed. Tissue nitrate concentrations in these plants from 4 weeks after emergence onwards were negligible, while leaf total N concentrations exceeded 2.36%. Salt toxicity occurred at 29 and 43 mmol NIL, and it sometimes reduced tissue N concentrations so that adequacy and toxicity concentrations overlapped. Critical tissue N concentrations declined over the growth period, the largest decline occurring for nitrate. Critical tissue N concentrations for YFEL, from 2 weeks after emergence to final harvest were: petiole sap nitrate-N, 1.2-0.2 g/L; petiole nitrate-N, 2.1-0.1%; leaf nitrate-N, 0.44-0.08%. Critical tissue nitrate concentrations clearly differentiated between inadequate and adequate N application levels. Critical leaf total N concentrations only differentiated between inadequate and marginal N application rates, except for OL when inadequate and marginally adequate (80-90% maximum yield) concentrations were not different (P>0.05). Nitrogen application level affected (P<0.05) leaf potassium, phosphorus, calcium (Ca), magnesium (Mg) and sulfur concentrations. The largest effects were recorded for Ca and Mg where increasing N application level reduced leaf nutrient concentration. Petiole sap nitrate concentrations can be used as a rapid field test for distinguishing between a deficient and an adequate N supply. Where concentrations exceed critical values, they can be interpreted as such because N fertiliser toxicity rarely occurs under field conditions.

Determination of critical nitrogen concentrations of zucchini squash (Cucurbita pepo L.) cv. Blackjack grown in sand culture

1991 ◽  
Vol 31 (6) ◽  
pp. 835 ◽  
Author(s):  
DO Huett ◽  
E White
Keyword(s):  
Growth Rate ◽  
Growth Period ◽  
Sand Culture ◽  
Total N ◽  
N Supply ◽  
Nitrate N ◽  
Fruit Harvest ◽  
Petiole Sap ◽  
Leaf Nitrate

A gamma x quadratic response surface model was used to predict the growth rate over the 14-week growth period of zucchini squash (Cucurbita pepo L.) cv. Blackjack in sand culture with nitrogen (N) levels of 2, 7, 14, 29 and 43 mmol/L. Growth rate relative to maximum was plotted against tissue N concentration every 2 weeks, to derive diagnostic petiole sap; leaf nitrate-N and leaf total-N in youngest fully opened leaf, youngest fully expanded leaf and oldest green leaf; and total N in bulked leaf samples. Critical concentrations corresponding to 90% maximum growth rate for deficiency and toxicity are presented. Petiole sap and leaf nitrate-N were much more responsive than leaf total N concentrations over the 2-14 mmol N/L range where positive growth responses were recorded. At 2 mmol N/L, plants were severely N-deficient and growth rate was low (1.6 g/plant.week at fruit set). Tissue nitrate concentrations were negligible, while leaf total N concentrations exceeded 2.6%. Salt toxicity occurred at 29 and 43 mmol N/L, and at the highest N level, tissue N concentrations were sometimes reduced so that concentration ranges for adequacy and toxicity overlapped. Critical tissue N concentrations always exceeded (P<0.05) levels recorded in plants receiving a marginally deficient N level (7 mmol/L). Critical petiole sap and leaf nitrate-N concentrations were much more variable between sampling periods than leaf total N concentrations. Adequate concentration ranges (values between critical concentrations for deficiency and toxicity) were determined for the pre-fruit harvest (weeks 2-6) and fruit harvest (weeks 8-14) growth stages where values were common for consecutive weeks within each sampling period. It was only possible to determine adequate concentrations over the entire growth period for bulked leaf total N (4.30440% prefruit harvest and 4.15-4.45% fruit harvest). Concentrations of potassium (K), phosphorus and sulfur were affected (P<0.05) by N application level, with the largest effect being recorded for K. This confirms the importance of optimising N supply when determining critical levels of these nutrients for zucchini squash. Determination of petiole sap nitrate-N concentrations in the field can be used to distinguish between a deficient and an adequate N supply, but the large variation in values between sampling periods renders this technique less reliable than leaf total N. Tissue N concentrations which exceed critical deficient levels can be interpreted as such because they were recorded when growth was depressed at high N levels. This will rarely occur under field conditions.

Diagnostic nitrogen concentrations for cabbages grown in sand culture

1989 ◽  
Vol 29 (6) ◽  
pp. 883 ◽  
Author(s):  
DO Huett ◽  
G Rose
Keyword(s):  
Growth Rate ◽  
Growth Period ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Sand Culture ◽  
Total N ◽  
Rate Range ◽  
Nitrate N ◽  
N Concentration ◽  
Petiole Sap

The cabbage cv. Rampo was grown in sand culture with 5 nitrogen (N) levels, between 2 and 43 mmol/L, applied as nitrate each day in a complete nutrient solution. The youngest fully opened leaf (YFOL), which became the wrapper leaf at heading, the youngest fully expanded leaf (YFEL) and the oldest green leaf (OL) were harvested at a minimum of 2-week intervals over a 12-week growth period. Standard laboratory leaf total N and nitrate-N determinations and rapid petiole sap nitrate-N determinations were conducted on YFOL, YFEL and OL. Total N was also determined in bulked leaves. The relationship between growth rate relative to the maximum at each sampling time and leaf N concentration was used to derive diagnostic petiole sap nitrate-N, leaf nitrate-N and total N in YFOL, YFEL and OL and bulked leaf total N concentrations. Critical concentration corresponded to 90% maximum growth rate and adequate concentration corresponded to 9 1-1 00% maximum growth rate. Petiole sap nitrate-N concentration, which can be measured rapidly in the field, and leaf nitrate-N concentration were very responsive to N application where positive growth responses were recorded. Critical N concentrations are presented for all leaves at most sampling times throughout the growth period. Critical total N concentrations in YFOL, YFEL and bulked leaves were higher during the pre-heading growth stage (weeks 2-6) than the post-heading growth stage (weeks 8-12). Critical N concentrations were inconsistent over the growth period and it was not possible to present single values to represent the full growth period, with 2 exceptions. A critical petiole sap nitrate-N concentration for OL of 3.0 g/L can be recommended for the full growth period because it represents a percentage of maximum growth rate range of 88-95%. Similarly, for YFEL, a critical total N concentration of 4.10% pre-heading (range 4.10-4.38%) represents a percentage maximum growth rate range of 62-90% and a post-heading critical total N concentration of 3.10% (range 3.10-3.50%) represents a percentage maximum growth rate range of 76-90%. The concentrations of potassium, phosphorus, calcium, magnesium and sulfur in YFOL, YFEL, OL and bulked leaf corresponding to N treatments producing maximum growth rates are also presented.

Diagnostic nitrogen concentrations for tomatoes grown in sand culture

1988 ◽  
Vol 28 (3) ◽  
pp. 401 ◽  
Author(s):  
DO Huett ◽  
G Rose
Keyword(s):  
Critical Values ◽  
Sand Culture ◽  
Nutrient Concentrations ◽  
Total N ◽  
Nitrate N ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Petiole Sap ◽  
N Status ◽  
Leaf N

The tomato cv. Flora-Dade was grown in sand culture with 4 nitrogen (N) levels of 1.07-32.14 mmol L-1 applied as nitrate each day in a complete nutrient solution. The youngest fully opened leaf (YFOL) and remaining (bulked) leaves were harvested at regular intervals over the 16-week growth period. Standard laboratory leaf total and nitrate N determinations were conducted in addition to rapid nitrate determinations on YFOL petiole sap. The relationships between plant growth and leaf N concentration, which were significantly affected by N application level, were used to derive diagnostic leaf N concentrations. Critical and adequate concentrations in petiole sap of nitrate-N, leaf nitrate-N and total N for the YFOL and bulked leaf N were determined from the relationship between growth rate relative to maximum at each sampling time and leaf N concentration. YFOL petiole sap nitrate-N concentration, which can be measured rapidly in the field by using commercial test strips, gave the most sensitive guide to plant N status. Critical values of 770-1 120 mg L-I were determined over the 10-week period after transplanting (first mature fruit). YFOL (leaf + petiole) total N concentration was the most consistent indicator of plant N status where critical values of4.45-4.90% were recorded over the 4- 12 week period after transplanting (early harvests at 12 weeks). This test was less sensitive but more precise than the petiole sap nitrate test. The concentrations of N, potassium, phosphorus, calcium and magnesium in YFOL and bulked leaf corresponding to the N treatments producing maximum growth rates are presented, because nutrient supply was close to optimum and the leaf nutrient concentrations can be considered as adequate levels.

scholarly journals Effects of nitrogen accumulation and partitioning of dry matter and nitrogen of vegetables. 1. Brussels sprouts

1995 ◽  
Vol 43 (4) ◽  
pp. 419-433
Author(s):  
H. Biemond ◽  
J. Vos ◽  
P.C. Struik
Keyword(s):  
Dry Matter ◽  
Leaf Number ◽  
Nitrogen Accumulation ◽  
N Accumulation ◽  
Total N ◽  
Brussels Sprouts ◽  
Apical Buds ◽  
Nitrate N ◽  
N Concentration ◽  
Final Harvest

Three greenhouse trials and one field trial were carried out on Brussels sprout cv. Icarus SG2004 in which the treatments consisted of different N amounts and application dates. DM and N accumulation in stems, apical buds and groups of leaf blades, petioles and sprouts were measured frequently throughout crop growth. Total amounts of accumulated DM and N were affected by amount of N applied and date of application, but the final harvest indexes for DM and N (0.10-0.35 and 0.20-0.55, respectively) were not significantly affected by treatments in most experiments. Nitrate N concentrations were only high (up to about 2%) shortly after planting. The total N concentration of leaf blades and petioles increased with increasing leaf number. This increase resulted from a decreasing N concentration during the leaf's life. The total N concentration in sprouts changed little with leaf number.

The effect of interval between harvests and nitrogen application on the concentration of nitrate-nitrogen in the total herbage, green leaf and ‘stem’ of grasses

1986 ◽  
Vol 106 (3) ◽  
pp. 467-475 ◽  
Author(s):  
D. Wilman ◽  
P. T. Wright
Keyword(s):  
Field Experiment ◽  
Perennial Ryegrass ◽  
Nitrate Nitrogen ◽  
Italian Ryegrass ◽  
Green Leaf ◽  
N Application ◽  
Total N ◽  
Nitrate N ◽  
N Concentration ◽  
Time Of Year

SummaryThe effect of six intervals between harvests and three levels of N application on the concentration of nitrate-N and total N in total herbage, green leaf and ‘stem’ was studied in two varieties of perennial ryegrass during 30-week periods in each of the first two harvest years of a field experiment. The effect of two intervals between harvests on the concentration of nitrate-N in Italian ryegrass total herbage was studied in the same experiment. The effect of two intervals between harvests and three levels of N application on the concentrations of nitrate-N and total N in total herbage was studied in five grasses during a 32-week period in a second field experiment.Increasing the interval between harvests tended to increase the concentration of nitrate-N in herbage; however, this seemed due mainly to the average date of harvest being later in the year with the longer intervals. The concentration of nitrate-N in herbage increased from June to September. Italian and hybrid ryegrass and tall fescue were much higher than perennial ryegrass in nitrate-N concentration at the highest level of applied N (525 kgN/ha per year). Apart from the species and time of year effects, the nitrate-N concentration seemed to be determined mainly by the amount of N applied divided by the number of days between the date of application and the date of sampling. The ‘stem’ of perennial ryegrasa tended to be slightly higher in nitrate-N concentration than green leaf. The proportion of nitrate-N in total N was increased by increasing the interval between harvests and by applying N and was nearly twice as high in ‘stem’ as in green leaf. Both the nitrate-N and the total N concentration of herbage, particularly the latter, seemed to be inversely related to solar radiation receipt.

Within-season grass herbage crude-protein- and nitrate-N concentrations as affected by rates and seasonal distribution of fertilizer nitrogen in a high yearly rainfall climate

2000 ◽  
Vol 80 (2) ◽  
pp. 277-285 ◽  
Author(s):  
S. Bittman ◽  
C. G. Kowalenko
Keyword(s):  
Crude Protein ◽  
Residual Effect ◽  
Residual Effects ◽  
Single Application ◽  
N Application ◽  
Total N ◽  
Nitrate N ◽  
N Concentration ◽  
Application Rates ◽  
Poor Indicator

An orchardgrass study in which three rates of N (100, 200 and 400 kg ha−1) each distributed in 1/0/0/0, 0.75/0.25/0/0, 0.50/0.25/0.25/0 and 0.25/0.25/0.25/0.25 proportions prior to four cut intervals examined crude-protein-N and nitrate-N concentrations in grass herbage at each cut in three trials. Crude-protein-N concentration frequently increased to a greater degree and in a different pattern (based on cut) than yield as the rate of N application increased. This showed that crude-protein-N by itself cannot be used as a method for determining the N sufficiency status of grass. Both rate and distribution of fertilizer N strongly influenced plant nitrate-N concentration; the degree of change varied considerably among cuts and trials. Plant nitrate-N concentration in the control did not correspond to yield responsiveness to N application, making it a poor indicator of the plant's need for fertilizer applications. Residual effects of N applications on plant nitrate-N were noted into the last cut of the season from a single spring application. The effect of N rate and distribution, then, was a function of immediate and residual effects of the applications. There was some evidence that N present in the soil in nitrate-N form enhanced the potential for high nitrate-N in the plant. Plant nitrate-N concentrations accounted for up to 29% of the total N in the plant with concentrations greater than 4000 mg N kg−1 at the highest N application rates. Plant nitrate-N did not exceed 1000 mg N kg−1, a concentration considered safe for ruminants, when 75 kg N ha−1 or less ammonium nitrate was applied as a single application prior to a growth interval for all cuts. Since grass protein- and nitrate-N concentrations respond differently than yield to N applications, a specific combination of rate and distribution of fertilizer will not necessarily produce maximum herbage quantity and quality simultaneously. Key words: Crude-protein-N, plant nitrate-N, residual effect, split applications

Assessment of the nitrogen and potassium status of irrigated Brussels sprouts (Brassica oleracea L. var. gemmifera) by plant analysis

1996 ◽  
Vol 36 (7) ◽  
pp. 887 ◽  
Author(s):  
CMJ Williams ◽  
NA Maier
Keyword(s):  
Total Yield ◽  
Leaf Age ◽  
Plant Analysis ◽  
Total N ◽  
Brussels Sprouts ◽  
Critical Concentrations ◽  
N Supply ◽  
Nitrate N ◽  
N Concentration ◽  
N Status

Four field experiments were carried out during 1992-93 (sites 1 and 2) and 1993-94 (sites 3 and 4) to assess the effects of nitrogen (N), at rates up to 600 kgha, and potassium (K), at rates up to 300 kgha, on total N, nitrate-N and K concentrations in petioles of the youngest fully expanded leaves (P-YFEL) of Brussels sprouts (Brassica oleracea var. gemmifera). The experiments were located in commercial plantings in the Mt Lofty Ranges, South Australia. Plant samples were collected at 2-4-week intervals from 4 to 28 weeks after the plants were transplanted. Temporal or seasonal variation, and the effects on concentrations of total N, nitrate-N and K of sampling leaves next in age (YFEL-1 to YFEL+2) to the index leaf, were also studied. Total N concentration in P-YFEL was more sensitive to variations in N supply than nitrate-N at all sites. Total N and nitrate-N concentrations in petioles also varied with the age of the leaf sampled. Total N concentrations in petioles of leaves sampled 4-16 weeks after transplanting decreased with increasing leaf age. In contrast, nitrate-N concentrations in petioles sampled 4-8 weeks after transplanting increased with leaf age. Potassium concentrations in petioles did not vary consistently between leaves of different age. From 4 to 6 weeks after transplanting, relationships between total N or nitrate-N concentrations in P-YFEL and relative total yield were not significant (P>0.05), therefore, critical concentrations could not be determined. Linear and quadratic models were used to study the relationships between total N and nitrate-N concentration in P-YFEL and relative total yield during 8-28 weeks after transplanting. Total N concentrations accounted for a greater amount of variation in relative total yield at 10, 12, 14, 16, 18, 20, 24 and 28 weeks after transplanting compared with nitrate-N. Coefficients of determination (r2) were in the range 0.52-0.93. Relationships between nitrate-N concentration in P-YFEL and relative total yield were only significant 8, 10, 14 and 16 weeks after transplanting and 9 values were in the range 0.49-0.82. Critical concentrations for total N decreased from 3.13-3.44% at 10 weeks to 1.22-1.38% at 28 weeks after transplanting. This decrease highlights the importance of carefully defining sampling time to ensure correct interpretation of plant test data. Potassium concentrations also decreased between 4 and 28 weeks after transplanting. Critical concentrations were not determined for K, because the crops at all sites did not respond significantly (P>0.05) to applied K. Based on sensitivity (as indicated by the range in tissue concentrations in response to variations in N supply) and on the correlations between total N and nitrate-N concentrations and relative total yield, we concluded that total N was better than nitrate-N as an indicator of plant N status and yield response of Brussels sprouts. We suggested that growers sample P-YFEL several times during the growing season, starting 10 weeks after transplanting. Plant analysis can be used to monitor N status and to detect N deficiencies which may arise during the growing season of Brussels sprouts which may be up to 9 months duration. Growers can adjust their fertiliser N program to ensure deficiencies are quickly corrected.

Total nitrogen concentration in leaves of potatoes (Solanum tuberosumL.) as an index of nutritional status

1976 ◽  
Vol 87 (2) ◽  
pp. 293-296 ◽  
Author(s):  
A. Gupta ◽  
M. C. Saxena
Keyword(s):  
Total Nitrogen ◽  
Tuber Yield ◽  
Critical Concentration ◽  
Nitrogen Concentration ◽  
Curvilinear Relationship ◽  
N Application ◽  
Total N ◽  
Potato Plants ◽  
N Concentration ◽  
Total Nitrogen Concentration

SummaryLeaf samples were collected, at weekly intervals, throughout the growing season, from potato (Solanum tuberosumL.) plants supplied with varying amounts of nitrogen (0, 60, 120, 180 and 240 kg N/ha) and analysed for total N. Application of nitrogen increased the N concentration in the green leaves at all stages of growth. There was a significant curvilinear relationship between the final tuber yield and the total N concentration in the leaves at 48–90 days after planting in 1968–9 and at 79–107 days after planting in 1969–70. The N concentration at 70–90 days after planting was consistently related to the final tuber yield in both years. Thus this period was ideal for assessing the nitrogen status of potato plants. The critical concentration of total nitrogen generally decreased with advance in age. It ranged from 4·65% at 76 days to 3·30% at 90 days during 1968–9, whereas in 1969–70 it ranged from 4·20% at 79 days to 3·80% at 93 days. During the period from 83 to 86 days the critical percentage was around 3·6% in both the years.

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