Critical sulfur concentrations in oilseed rape (Brassica napus) in relation to nitrogen supply and to plant age

1998 ◽  
Vol 38 (5) ◽  
pp. 511 ◽  
Author(s):  
A. Pinkerton
Keyword(s):  
Oilseed Rape ◽  
Seed Yield ◽  
Critical Values ◽  
Sand Culture ◽  
Culture Experiment ◽  
Total N ◽  
N Supply ◽  
S Deficiency ◽  
Time Required ◽  
Time Critical

Summary. Oilseed rape was grown in a sand culture experiment in a glasshouse to derive values for plant testing for the diagnosis of sulfur (S) deficiency and for the prediction of seed yield. Five rates of S, combined factorially with 4 rates of nitrogen (N), maintained constant throughout the experiment, were used to determine critical concentrations of S fractions and ratios (total S, St; sulfate-S, SO4; total N/total S, N/St; SO4/St). The most satisfactory indices of rapeseed S status for diagnosis or prediction were St and SO4. Whole shoots and youngest fully expanded leaves exhibited similar critical values in plants at the rosette stage, and critical values (St = 0.20–0.25%; SO4 = 230–460 mg/kg) changed little with time. Critical values for N/St changed with time, required 2 analyses, and gave no indication of the degree of deficiency when used to predict yield. Critical values of SO4/St depended on N supply, so 3 analyses were needed. It is argued that high critical values reported previously for prediction of seed yield have been obtained when there was a decline in soil-available S and plants relied on S taken up during early growth.

Critical phosphorus concentrations in oilseed rape (Brassica napus) and Indian mustard (Brassica juncea) as affected by nitrogen and plant age

1991 ◽  
Vol 31 (1) ◽  
pp. 107 ◽  
Author(s):  
A Pinkerton
Keyword(s):  
Oilseed Rape ◽  
Stem Elongation ◽  
Indian Mustard ◽  
Critical Values ◽  
Plant Age ◽  
Sand Culture ◽  
Mustard Seed ◽  
P Deficiency ◽  
N Supply ◽  
Oil Concentration

Oilseed rape and Indian mustard were grown in sand culture experiments in a glasshouse to derive values for a tissue test for the diagnosis of phosphorus (P) deficiency. Seven rates of P, combined factorially with 3 rates of nitrogen (N), were used to determine critical P concentrations. Suitable tissues to sample for a diagnostic test were the whole shoot of both species at any stage, or the youngest fully expanded leaf of rape and leaves 4-6 of mustard at the rosette stage. Critical P concentrations depended on both plant age and N supply. The critical values reported here for rape agreed closely with critical values found previously in tissues of field-grown crops of similar phenological age. Critical P levels in whole rape shoots adequately supplied with N decreased from 0.29% at the early rosette stage to 0.21% at the late rosette or yellow bud stage, while critical values in mustard fell from 0.25% at the early rosette stage to 0.18% at stem elongation to full flower. Critical P concentrations for prediction of seed yield were slightly higher (0.05% higher at the rosette stage). A nutrient supply with high P and high N reduced the seed oil concentration of both species; a low P and high N supply reduced the oil concentration in rape seed but increased it in mustard seed.

Sulphur uptake, yield responses and the interactions between nitrogen and sulphur in winter oilseed rape (Brassica napus)

1996 ◽  
Vol 126 (1) ◽  
pp. 53-62 ◽  
Author(s):  
S. P. McGrath ◽  
F. J. Zhao
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Seed Yield ◽  
Early Flowering ◽  
Utilization Efficiency ◽  
Winter Oilseed Rape ◽  
N Application ◽  
Total N ◽  
S Deficiency ◽  
Yield Responses

SUMMARYField experiments were conducted to test the seed yield responses of winter oilseed rape (Brassica napus L., cvs Libravo or Falcon) to the addition of different rates of S fertilizer, at three N application rates, on a sandy loam at Woburn, Bedfordshire, in 1990/91, 1991/92 and 1993/94. Large increases in seed yields, ranging from 0·7 to 1·6 t/ha, or 42–267% on a relative scale, were obtained in response to the application of 40 kg S/ha with 180 and 230 kg N/ha treatments. The effects of S were highly significant in 1991/92 (P < 0·01) and 1993/94 (P < 0·001) and close to significant (P = 0·053) in 1990/91. The yield benefits were obtained mainly from the application of the first 10 kg S/ha and further yield increases were unlikely above 40 kg S/ha. Increasing N application from 180 to 230 kg/ha decreased seed yield in 1990/91 and 1993/94, when no S was applied. In contrast, seed yield was not increased by S at zero or low (50 or 100 kg/ha) N rates. The interactions between N and S on seed yield were significant (P < 0·05) in 1990/91 but not in the other two seasons. Application of S also increased seed oil content in 1993/94, when the degree of S deficiency was particularly severe. With an application of 230 kg N/ha, the crops took up 5–22 kg S/ha at maturity when no S was applied and 26–51 kg S/ha when 40 kg S/ha was applied. The utilization efficiency of the fertilizer S ranged from 50 to 73% in the three seasons. Although the concentrations of total N in plants were largely unaffected by S treatments, large amounts of NO3-N accumulated in the leaves of S-deficient plants in 1993/94. This indicates that N metabolism was disrupted by S deficiency. The concentrations of S and the N: S ratios in different tissues and the whole plant changed considerably with time. The concentration of S in leaves at early flowering was found to be the best index in predicting S deficiency in terms of seed yield, and a critical value of 3·8 mg/g was obtained. In comparison, the N: S ratio in leaves at early flowering was a much poorer predictor of S deficiency.

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.

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.

Critical nitrate-nitrogen and total nitrogen concentrations for vegetative growth and seed yield of Linola (edible-oil linseed) as affected by plant age

1995 ◽  
Vol 35 (2) ◽  
pp. 239 ◽  
Author(s):  
PJ Hocking
Keyword(s):  
Seed Yield ◽  
Vegetative Growth ◽  
Edible Oil ◽  
Plant Age ◽  
Main Stem ◽  
Stem Tissue ◽  
Total N ◽  
N Supply ◽  
Nitrate N ◽  
N Status

Edible-oil linseed (Linola, CSIRO Australia) was grown in a sand culture experiment in a glasshouse to develop tissue tests for assessing the nitrogen (N) status of the crop. Seven rates of N, provided as nitrate, were used to obtain critical N concentrations. Plants were tissue-tested at 3 developmental stages: early tillering (TL), flower buds visible (BV), and the start of flowering (SF). Suitable tissues for tests based on nitrate-N were the upper half of the main stem and the whole main stem. Leaves were unsuitable as their nitrate-N concentration was unresponsive to N supply until well above the rate for maximum growth. For tests based on total N, suitable tissues were upper stem, upper leaves, total stem, total leaves, and whole shoot. Critical N supply rates for vegetative growth at TL, BV, and SF, respectively, were 85, 145, and 145 mg/L. The critical N supply rate for seed yield was 65 mg/L. Excessive N supplies (350, 700 mg N/L) reduced both seed oil percentage and seed yield. Critical nitrate-N concentrations in fresh, upper stem tissue for vegetative growth decreased from-0.26 to 0.16 mg/g fresh weight (FW) between stages TL and BV. A critical nitrate-N concentration for seed yield could only be obtained for fresh stem tissue at TL, and this value was 50% lower than that for vegetative growth. Critical nitrate-N concentrations [mg/g dry weight (DW)] in dried stem tissue for vegetative growth at TL, BV, and SF, respectively, were 2.3, 1.7, and 0.7 (upper stem); and 2.1, 1.1, and 0.6 (whole stem). Critical nitrate N values (mg/g DW) for seed yield at TL, BV, and SF were 1.1, 0.8, and 0.3 (upper stem); and 1.0,0.7, and 0.2 (whole stem). Critical total N concentrations (% DW) for vegetative growth at TL, BV, and SF, respectively, were 3.0, 2.3, and 2.2 (upper stem); 5.3, 5.8, and 4.5 (upper leaves); 2.2, 1.7, and 1.6 (whole stem); 5.5, 4.9, and 4.5 (total leaves); and 4.5, 3.1, and 2.7 (whole shoot). Corresponding total N values (% DW) for seed yield at TL, BV, and SF, respectively, were 2.9, 2.2, and 2.0 (upper stem); 5.2, 4.8, and 4.3 (upper leaves); 2.1, 1.4, and 1.4 (whole stem); 5.2, 4.4, and 4.2 (total leaves); and 4.3,2.8, and 2.6 (whole shoot). The upper stem is the preferred tissue when testing for nitrate-N, and the whole shoot is the most convenient tissue for total N. Tissue testing for N status of Linola needs to be matched closely to plant age or stage of development because of the decline in critical N concentrations between early tillering and flowering.

Assessment of sulphur deficiency in commercial oilseed rape crops from plant analysis

2013 ◽  
Vol 152 (4) ◽  
pp. 616-633 ◽  
Author(s):  
X. SARDA ◽  
S. DIQUELOU ◽  
M. ABDALLAH ◽  
N. NESI ◽  
O. CANTAT ◽  
...  
Keyword(s):  
Oilseed Rape ◽  
Principal Component ◽  
Organic N ◽  
Plant Analysis ◽  
Nitrate Accumulation ◽  
Rainfall Gradient ◽  
N Supply ◽  
S Deficiency ◽  
N Metabolism ◽  
Highly Correlated

SUMMARYSulphur (S) is one of the six main macroelements required to sustain the growth of plants. Sources include soil, fertilizer and atmospheric deposition, which has been reduced by 85% over the last three decades. Risks of S deficiencies are now recognized in high S-demanding species such as Brassica napus L. With the aims of evaluating the risk of excessive or insufficient fertilization and identifying robust relationships that may be used as plant S status indicators, 57 commercial crops of oilseed rape were selected among contrasting soils and along a rainfall gradient that may affect soil S availability. Cultivation practices were investigated and the S and nitrogen (N) concentrations of soil, senescing leaves, stems and seeds were analysed. Despite an excessive organic N supply and large variation in S supply (from 0 to 112 kg S/ha), principal component analysis using 43 parameters indicated that seed yield was poorly related to N and S fertilization rates. While the N and protein-N concentrations in seeds were inversely related to oil and glucosinolate concentrations, they were linked to S and sulphate (SO42−) accumulation in the seeds. Sulphate concentrations in senescing leaves, stems or seeds could be deduced from total S concentrations, as they were positively and highly correlated. Sulphate accounted for on average 0·69 of total S in senescing leaves with minimum and maximum values of 0·007 and 0·94, which revealed conditions of limited and excess supply of S, respectively. This high variation of SO42− concentration in leaves can be interpreted as the result of its mobilization triggered by S deficiency, but cannot be used alone as an indicator of plant S status. A comparison with plants grown in controlled conditions under different S supplies suggests that the intensity of S starvation affects N metabolism, leading to NO3− (nitrate) accumulation. It is further suggested that dual evaluation of SO42− and NO3− concentrations in senescing leaves could be used at the vegetative stage as a field indicator to adjust S fertilization.

scholarly journals Dynamics of Growth and Nitrogen Capture in Winter Oilseed Rape Hybrid and Line Cultivars under Contrasting N Supply

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1183 ◽  
Author(s):  
Yangyang Zhang ◽  
Piaopiao Lu ◽  
Tao Ren ◽  
Jianwei Lu ◽  
Li Wang
Keyword(s):  
Oilseed Rape ◽  
Seed Yield ◽  
Field Experiments ◽  
N Uptake ◽  
Genotypic Variation ◽  
Utilization Efficiency ◽  
Winter Oilseed Rape ◽  
N Accumulation ◽  
N Supply ◽  
Parental Lines

Cultivation of winter oilseed rape hybrids has been introduced as a promising solution to improve the nitrogen use efficiency (NUE) and to reduce the large N balance surpluses in this crop. To achieve a better understanding of the underlying physiological mechanisms, field experiments were conducted over two years to investigate the dynamics of growth and N capture in an oilseed rape hybrid and its parental lines under both low (0 kg ha−1) and high (180 kg ha−1) N supply. The results showed that the dynamic trajectories of crop growth and N capture could be accurately characterized by logistic equation using growing degree days as the independent variable. At both N rates, the oilseed rape hybrid outperformed the parental lines in seed yield and aboveground biomass accumulation, which was more closely associated with the longer duration (td) of the rapid growth period (RGP), than with the higher maximum growth rate (vm). N uptake was the main factor driving genotypic variation in seed yield, with an increasing importance of N utilization efficiency at high N supply. The hybrid had significantly higher N uptake than the parental lines at both low and high N supply, because of larger vm for N accumulation during the RGP, which may present a scope for genetically improving NUE in oilseed rape. High N application enhanced crop biomass production and N accumulation, as a result of prolonged td and larger vm during the RGP. The initiation of RGP for N accumulation occurred after overwinter period, which could not be accelerated by high N supply, suggesting rational distribution of N fertilizer with reduced basal dose. However, larger amounts in spring would be beneficial for a better synchronization to crop N demand with lower environmental risks.

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.

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