Assessment of the phosphorus status of oilseed rape by plant analysis

1989 ◽  
Vol 29 (6) ◽  
pp. 861 ◽  
Author(s):  
A Pinkerton ◽  
K Spencer ◽  
AG Govaars
Keyword(s):  
Field Experiments ◽  
Maximum Yield ◽  
Plant Part ◽  
Plant Analysis ◽  
Triple Superphosphate ◽  
P Deficiency ◽  
P Concentration ◽  
Critical P Concentration ◽  
Phosphorus Status ◽  
P Supply

Phosphorus (P) concentrations in young plants of rapeseed (Brassica napus cv. Wesway) were related to seed and oil yields to develop a tissue test for the diagnosis of P deficiency. Critical P concentrations were defined as those concentrations required to sustain 90% of maximum yield. In 2 field experiments in successive seasons on a P-deficient soil, rates of triple superphosphate from 2.5 to 120 kg/ha were banded with the seed. The lowest P concentration in young shoots (17-19 weeks from sowing) associated with a P supply that was adequate for plant growth was approximately 0.31%. The youngest fully-expanded leaf was a reliable plant part to sample, its P concentration being about 0.05% lower than the concentration of the whole shoot. Critical P concentrations in young plants for sustaining 90% of maximum seed and oil yields were higher, namely 0.33 and 0.28% for whole shoots and youngest fully-expanded leaves respectively. The critical P concentration in seeds was about 0.35%.

Critical phosphorus levels in sunflower plants

1981 ◽  
Vol 21 (108) ◽  
pp. 91 ◽  
Author(s):  
K Spencer ◽  
CW Chan
Keyword(s):  
Field Experiments ◽  
Maximum Yield ◽  
Dry Weight ◽  
Plant Part ◽  
Weight Basis ◽  
P Deficiency ◽  
P Concentration ◽  
Glasshouse Experiment ◽  
Phosphorus Levels ◽  
Tissue Test

To provide a basis for a tissue test for the diagnosis of P deficiency in sunflower crops, the influence of plant part and age on the critical P percentage (P concentration in tissues required to sustain 90% of maximum yield) was examined. In a glasshouse experiment, the known mobility of phosphate within the plant was reflected in the occurrence of the highest P concentration in the youngest leaves. Laminae contained more P than petioles on a dry-weight basis. Stem internodes contained less P than the adjoining petiole near the base ofthe plant but more near the apex. Three field experiments indicated that the lamina of the youngest fully-expanded leaf was a suitable plant part for diagnosis. Critical P concentrations for this tissue decreased from about 0.35% at the fourth week from sowing to 0.20% at the tenth week.

Plant phosphorus status has a limited influence on the concentration of phosphorus-mobilising carboxylates in the rhizosphere of chickpea

2005 ◽  
Vol 32 (2) ◽  
pp. 153 ◽  
Author(s):  
Madeleine Wouterlood ◽  
Hans Lambers ◽  
Erik J. Veneklaas
Keyword(s):  
Root Systems ◽  
External Factors ◽  
Sand Culture ◽  
P Deficiency ◽  
Cicer Arietinum L ◽  
Split Root ◽  
Chickpea Cultivar ◽  
Phosphorus Status ◽  
Carboxylate Exudation ◽  
P Supply

Two experiments were conducted to investigate whether carboxylate exudation by chickpea (Cicer arietinum L.) is a response to phosphorus (P) deficiency or a constitutive trait. The effect of P supply on carboxylate concentrations in the plant and in the rhizosphere of chickpea cultivar Heera was studied in a sand culture. Plants were grown in pots supplied with 200 mL of solution containing 0–500 μm P every 3 d. Malonate was the main carboxylate exuded, and the main carboxylate in roots; shoots contained mainly citrate and malate. Contrary to what has been reported for other species, carboxylate concentrations in the rhizosphere decreased only slightly at high P supply, but they were still substantial. The effect of P supply on the rate of exudation was studied in a split-root sand culture. Root systems were split into two pots, one root half received no P and the other half received 200 mL of solution containing 0–500 μm P. The rhizosphere of both root halves contained similar concentrations of carboxylates, even when the plants received a different supply of P. Our results indicate that carboxylate exudation is determined by internal P rather than external factors. The fact that chickpea roots always exude carboxylates indicates that exudation in this species is largely constitutive.

scholarly journals Soil phosphorus–crop response calibration relationships and criteria for winter cereal crops grown in Australia

2013 ◽  
Vol 64 (5) ◽  
pp. 480 ◽  
Author(s):  
Richard Bell ◽  
Douglas Reuter ◽  
Brendan Scott ◽  
Leigh Sparrow ◽  
Wayne Strong ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Soil Type ◽  
Maximum Yield ◽  
National Database ◽  
Winter Cereal ◽  
Minimum Tillage ◽  
Soil P ◽  
Critical Concentrations ◽  
P Concentration ◽  
Critical P Concentration

Soil testing is the most widely used tool to predict the need for fertiliser phosphorus (P) application to crops. This study examined factors affecting critical soil P concentrations and confidence intervals for wheat and barley grown in Australian soils by interrogating validated data from 1777 wheat and 150 barley field treatment series now held in the BFDC National Database. To narrow confidence intervals associated with estimated critical P concentrations, filters for yield, crop stress, or low pH were applied. Once treatment series with low yield (<1 t/ha), severe crop stress, or pHCaCl2 <4.3 were screened out, critical concentrations were relatively insensitive to wheat yield (>1 t/ha). There was a clear increase in critical P concentration from early trials when full tillage was common compared with those conducted in 1995–2011, which corresponds to a period of rapid shift towards adoption of minimum tillage. For wheat, critical Colwell-P concentrations associated with 90 or 95% of maximum yield varied among Australian Soil Classification (ASC) Orders and Sub-orders: Calcarosol, Chromosol, Kandosol, Sodosol, Tenosol and Vertosol. Soil type, based on ASC Orders and Sub-orders, produced critical Colwell-P concentrations at 90% of maximum relative yield from 15 mg/kg (Grey Vertosol) to 47 mg/kg (Supracalcic Calcarosols), with other soils having values in the range 19–27 mg/kg. Distinctive differences in critical P concentrations were evident among Sub-orders of Calcarosols, Chromosols, Sodosols, Tenosols, and Vertosols, possibly due to differences in soil properties related to P sorption. However, insufficient data were available to develop a relationship between P buffering index (PBI) and critical P concentration. In general, there was no evidence that critical concentrations for barley would be different from those for wheat on the same soils. Significant knowledge gaps to fill to improve the relevance and reliability of soil P testing for winter cereals were: lack of data for oats; the paucity of treatment series reflecting current cropping practices, especially minimum tillage; and inadequate metadata on soil texture, pH, growing season rainfall, gravel content, and PBI. The critical concentrations determined illustrate the importance of recent experimental data and of soil type, but also provide examples of interrogation pathways into the BFDC National Database to extract locally relevant critical P concentrations for guiding P fertiliser decision-making in wheat and barley.

Relationship between P and N concentrations in timothy

1999 ◽  
Vol 79 (1) ◽  
pp. 65-70 ◽  
Author(s):  
G. Bélanger ◽  
J. E. Richards
Keyword(s):  
N Fertilization ◽  
Phleum Pratense ◽  
Growth And Yield ◽  
Shoot Biomass ◽  
P Deficiency ◽  
P Concentration ◽  
N Concentration ◽  
Critical P Concentration ◽  
The Relationship ◽  
Phleum Pratense L

Tools quantifying the status of N and P in plants may help to achieve efficient management of these nutrients and to optimize crop growth and yield. The objective of this study was to establish the relationship between P and N concentrations during the regrowth of timothy (Phleum pratense L.) and, in particular, to estimate the critical P concentration required to diagnose P deficiency. The relationship between P and N concentrations was determined for timothy grown in two experiments conducted with early- and late-maturing cultivars under non-limiting N conditions in spring of 1991 and 1992, and in two experiments with four rates of N fertilization conducted in the spring of 1993 and the summer of 1994. Shoot biomass and P and N concentrations were determined weekly during each regrowth cycle. The P and N concentrations decreased with time in all four experiments. The decrease in P concentration with increasing shoot biomass was generally similar to the decrease in N concentration. The relationship between P concentration and shoot biomass was not different for early- and late-maturing timothy cultivars. This relationship, however, was affected by N fertilization. For a given shoot biomass, increasing N fertilization rates increased P concentration. The relationship between P and N concentrations under non-limiting N conditions is described by a linear relationship (P = 1.46 + 0.069N, R2 = 0.79, P < 0.001, n = 48) in which P concentration (P) and N concentration (N) are expressed in g kg−1 DM. The relationship between P and N concentrations was different under N limiting conditions. For a given N concentration, the P concentration was greater under limiting N conditions than under non-limiting N conditions. Our results show that the critical P concentration for shoot growth is a function of the N concentration in the shoot biomass and the level of N deficiency. The present study provides the relationship required to estimate the critical P concentration which is essential for quantifying levels of P deficiency in timothy, and in developing models to predict the quantity of fertilizer P needed to correct that deficiency. Key words: Phleum pratense L., timothy, nitrogen, phosphorus, grasses

Effects of Direct Drilling on the Phosphorus Uptake and Fertilizer Requirements of Wheat

1987 ◽  
Vol 38 (4) ◽  
pp. 775 ◽  
Author(s):  
PS Cornish
Keyword(s):  
Field Experiments ◽  
Maximum Yield ◽  
Phosphorus Uptake ◽  
Soil Surface ◽  
Dry Weight ◽  
Available Phosphorus ◽  
Potential Yield ◽  
P Concentration ◽  
P Fertilizer ◽  
Direct Drilling

The effect of direct drilling on the phosphorus (P) relations of ~vheatw as examined in seven field experiments over three years. Compared with conventional cultivation of the soil, direct drilling concentrated available phosphorus nearer the soil surface and resulted in higher strength and lower root length in surface soil (0-10 cm). Tissue-P concentration and dry weight of young plants (< 10 weeks) were consistently lower after direct drilling. It appeared therefore that direct drilling limited the uptake of soil phosphorus. An unknown factor also reduced plant dry weight per unit of P taken up in some experiments, whilst high rates of P fertilizer generally failed to give equal P concentration or dry weight in early growth. It is suggested that the young plants were unable to exploit fully the banded fertilizer because of insufficient adaptation of roots to the concentrated source of P and that this effect is a greater disadvantage for a direct-drilled crop. Direct drilling gave lower grain yields in four experiments when no fertilizer was applied, but where rates of P fertilizer were high, the two tillage treatments produced equal'pields. In these four experiments direct-drilled crops needed more fertilizer to attain 90% of the maximum yield. Crops in cultivated soil had the higher dry weight at anthesis and therefore the higher potential yield at equal rates of P fertilizer (in two years), but they failed to realize their potential at high rates of fertilizer because their greater vegetative growth led to increased water stress after flowering.

scholarly journals Leaf Phosphorus Concentration Regulates the Development of Cluster Roots and Exudation of Carboxylates in Macadamia integrifolia

2021 ◽  
Vol 11 ◽  
Author(s):  
Xin Zhao ◽  
Yang Lyu ◽  
Kemo Jin ◽  
Hans Lambers ◽  
Jianbo Shen
Keyword(s):  
Critical Value ◽  
Cluster Roots ◽  
Phosphorus Concentration ◽  
Acid Phosphatases ◽  
P Deficiency ◽  
Cluster Root ◽  
Macadamia Integrifolia ◽  
P Concentration ◽  
Leaf P ◽  
P Supply

Phosphorus (P) deficiency induces cluster-root formation and carboxylate exudation in most Proteaceae. However, how external P supply regulates these root traits in Macadamia integrifolia remains unclear. Macadamia plants were grown hydroponically with seven P levels to characterize biomass allocation, cluster-root development, and exudation of carboxylates and acid phosphatases. Plant biomass increased with increasing P supply, peaking at 5 μM P, was the same at 5–25 μM P, and declined at 50–100 μM P. Leaf P concentration increased with increasing P supply, but shoot biomass was positively correlated with leaf P concentration up to 0.7–0.8 mg P g–1 dry weight (DW), and declined with further increasing leaf P concentration. The number of cluster roots declined with increasing P supply, with a critical value of leaf P concentration at 0.7–0.8 mg P g–1 DW. We found a similar trend for carboxylate release, with a critical value of leaf P concentration at 0.5 mg g–1 DW, but the activity of acid phosphatases showed a gradually-decreasing trend with increasing P supply. Our results suggest that leaf P concentration regulates the development and functioning of cluster roots, with a critical P concentration of 0.5–0.8 mg g–1, above which macadamia growth is inhibited.

scholarly journals Relationships of Gibberellic Acid to Water and Phosphorus in the Growth, Sugar Production, and Enzyme Behavior of Sugarcane

1969 ◽  
Vol 53 (3) ◽  
pp. 149-166
Author(s):  
Alex G. Alexander
Keyword(s):  
Gibberellic Acid ◽  
Water Supply ◽  
Field Experiments ◽  
Maximum Growth ◽  
Sand Culture ◽  
Growth Responses ◽  
P Deficiency ◽  
P Content ◽  
Variable Water ◽  
P Supply

Immature sugarcane was subjected to variable water and phosphorus (P) supply and then treated with foliar gibberellic acid (GA). All plants were grown in sand culture and received initial water and P treatments at 88 days of age. Water regimes of inadequate, adequate, and abundant supply were established with 1, 2, and 4 liters of water per day, respectively. Variable P included 0, 6, and 30 meq./liter. Foliar GA was given as 0-, 0.01-, and 0.10-percent solutions. There were three objectives: 1 To determine the effectiveness of GA as a growth stimulant and regulator of sugar-enzyme relationships under conditions of water and P stress; 2, to explore physiological limits within which GA-enzyme relationships persist; and 3, to explore the enzyme basis of water and P performance under extreme conditions of GA-stimulated growth. The following results were recorded: 1. Both water and GA had greatly increased stalk weight and intemode length 5 weeks after GA treatment. 2. Water supply strongly affected GA-growth responses. Water-deficient plants were proportionately more stimulated by GA than water-rich plants. However, maximum growth required both GA and abundant water. 3. GA appeared to increase the efficiency of water utilization, regardless of the amount of water supplied. 4. Variable water supply severely transformed the behavior patterns of ATP-ase, amylase, invertase and polyphenol oxidase. 5. GA treatment of low-water plants appeared to increase the severity of water shortage. Hydrolytic enzymes were severely retarded by GA when water supply was low, but not when adequate or abundant water was available. On the basis of growth and enzyme data it was proposed that GA caused an internal redeployment of water so that the net quantity available for enzymatic functions was reduced. It was also proposed that GA might decrease the internal water supply while increasing growth, in contrast to the commercial practice of externally withholding water which decreases growth. 6. Low P was inadequate for maximum growth, but severe P deficiency was not achieved. GA was proportionally more effective in promoting fresh weights and internode elongation when P supply was low. 7. GA moderately increased leaf P content when P supply was low. The increase was primarily organic P (PO) and this was attributed to GA suppression of phosphatase and ATP-ase. The significance of GA alteration of PO is discussed. 8. Evidence was found of a GA-induced PO decline mediated by increased amylase activity. 9. Leaf peroxidase was extremely sensitive to P supply, and to GA in P-hungry plants. The enzyme was excessively active in low-P X low-GA plants. 10. It is shown that cane growth and enzymology is far more sensitive to P than field experiments have indicated. The importance of PO, phosphatases and phosphorylase, as contrasted to total P content, is stressed.

Wheat and white lupin differ in root proliferation and phosphorus use efficiency under heterogeneous soil P supply

2011 ◽  
Vol 62 (6) ◽  
pp. 467 ◽  
Author(s):  
Qifu Ma ◽  
Zed Rengel ◽  
Kadambot H. M. Siddique
Keyword(s):  
Root Zone ◽  
White Lupin ◽  
Cluster Roots ◽  
Phosphorus Use Efficiency ◽  
P Deficiency ◽  
Soil P ◽  
P Use Efficiency ◽  
P Concentration ◽  
Use Efficiency ◽  
P Supply

Heterogeneity of soil nutrients, particularly phosphorus (P), is widespread in modern agriculture due to increased adoption of no-till farming, but P-use efficiency and related physiological processes in plants grown in soils with variable distribution of nutrients are not well documented. In a glasshouse column experiment, wheat (Triticum aestivum L.) and white lupin (Lupinus albus L.) were subjected to 50 mg P/kg at 7–10 cm depth (hotspot P) or 5 mg P/kg in the whole profile (uniform P), with both treatments receiving the same amount of P. Measurements were made of plant growth, gas exchange, P uptake, and root distribution. Plants with hotspot P supply had more biomass and P content than those with uniform P supply. The ratios of hotspot to uniform P supply for shoot parameters, but not for root parameters, were lower in L. albus than wheat, indicating that L. albus was better able than wheat to acquire and utilise P from low-P soil. Cluster roots in L. albus were enhanced by low shoot P concentration but suppressed by high shoot P concentration. Soil P supply decreased root thickness and the root-to-shoot ratio in wheat but had little effect on L. albus. The formation of cluster roots in low-P soil and greater proliferation and surface area of roots in the localised, P-enriched zone in L. albus than in wheat would increase plant P use in heterogeneous soils. L. albus also used proportionally less assimilated carbon than wheat for root growth in response to soil P deficiency. The comparative advantage of each strategy by wheat and L. albus for P-use efficiency under heterogeneous P supply may depend on the levels of P in the enriched v. low-P portions of the root-zone and other soil constraints such as water, nitrogen, or potassium supply.

scholarly journals Corrigendum to: Soil phosphorus–crop response calibration relationships and criteria for winter cereal crops grown in Australia

2015 ◽  
Vol 66 (1) ◽  
pp. 112
Author(s):  
Richard Bell ◽  
Douglas Reuter ◽  
Brendan Scott ◽  
Leigh Sparrow ◽  
Wayne Strong ◽  
...  
Keyword(s):  
Confidence Intervals ◽  
Soil Type ◽  
Maximum Yield ◽  
National Database ◽  
Winter Cereal ◽  
Minimum Tillage ◽  
Soil P ◽  
Critical Concentrations ◽  
P Concentration ◽  
Critical P Concentration

Soil testing is the most widely used tool to predict the need for fertiliser phosphorus (P) application to crops. This study examined factors affecting critical soil P concentrations and confidence intervals for wheat and barley grown in Australian soils by interrogating validated data from 1777 wheat and 150 barley field treatment series now held in the BFDC National Database. To narrow confidence intervals associated with estimated critical P concentrations, filters for yield, crop stress, or low pH were applied. Once treatment series with low yield (CaCl2 1 t/ha). There was a clear increase in critical P concentration from early trials when full tillage was common compared with those conducted in 1995–2011, which corresponds to a period of rapid shift towards adoption of minimum tillage. For wheat, critical Colwell-P concentrations associated with 90 or 95% of maximum yield varied among Australian Soil Classification (ASC) Orders and Sub-orders: Calcarosol, Chromosol, Kandosol, Sodosol, Tenosol and Vertosol. Soil type, based on ASC Orders and Sub-orders, produced critical Colwell-P concentrations at 90% of maximum relative yield from 15 mg/kg (Grey Vertosol) to 47 mg/kg (Supracalcic Calcarosols), with other soils having values in the range 19–27 mg/kg. Distinctive differences in critical P concentrations were evident among Sub-orders of Calcarosols, Chromosols, Sodosols, Tenosols, and Vertosols, possibly due to differences in soil properties related to P sorption. However, insufficient data were available to develop a relationship between P buffering index (PBI) and critical P concentration. In general, there was no evidence that critical concentrations for barley would be different from those for wheat on the same soils. Significant knowledge gaps to fill to improve the relevance and reliability of soil P testing for winter cereals were: lack of data for oats; the paucity of treatment series reflecting current cropping practices, especially minimum tillage; and inadequate metadata on soil texture, pH, growing season rainfall, gravel content, and PBI. The critical concentrations determined illustrate the importance of recent experimental data and of soil type, but also provide examples of interrogation pathways into the BFDC National Database to extract locally relevant critical P concentrations for guiding P fertiliser decision-making in wheat and barley.

scholarly journals An R2R3-type myeloblastosis transcription factor MYB103 is involved in phosphorus remobilization

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Fangwei Yu ◽  
Shenyun Wang ◽  
Wei Zhang ◽  
Hong Wang ◽  
Li Yu ◽  
...  
Keyword(s):  
Cell Wall ◽  
Transcription Factor ◽  
Abiotic Stresses ◽  
Myb Transcription Factor ◽  
Ethylene Signaling ◽  
Biotic And Abiotic Stresses ◽  
P Deficiency ◽  
P Concentration ◽  
Increased Sensitivity

Abstract The members of myeloblastosis transcription factor (MYB TF) family are involved in the regulation of biotic and abiotic stresses in plants. However, the role of MYB TF in phosphorus remobilization remains largely unexplored. In the present study, we show that an R2R3 type MYB transcription factor, MYB103, is involved in phosphorus (P) remobilization. MYB103 was remarkably induced by P deficiency in cabbage (Brassica oleracea var. capitata L.). As cabbage lacks the proper mutant for elucidating the mechanism of MYB103 in P deficiency, another member of the crucifer family, Arabidopsis thaliana was chosen for further study. The transcript of its homologue AtMYB103 was also elevated in response to P deficiency in A. thaliana, while disruption of AtMYB103 (myb103) exhibited increased sensitivity to P deficiency, accompanied with decreased tissue biomass and soluble P concentration. Furthermore, AtMYB103 was involved in the P reutilization from cell wall, as less P was released from the cell wall in myb103 than in wildtype, coinciding with the reduction of ethylene production. Taken together, our results uncover an important role of MYB103 in the P remobilization, presumably through ethylene signaling.

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