The phosphorus requirement of lettuce

1973 ◽  
Vol 80 (1) ◽  
pp. 111-117 ◽  
Author(s):  
R. Smith ◽  
M. A. Scaife
Keyword(s):  
Adsorption Isotherm ◽  
Sandy Soil ◽  
Maximum Growth ◽  
P Adsorption ◽  
P Concentration ◽  
Phosphorus Requirement ◽  
Optimal Intensity ◽  
P Application ◽  
Leaf P ◽  
P Supply

SummaryThe optimal intensity of P supply for lettuce was investigated in a pot experiment with five soils, six levels of P application (0, 15, 30, 60, 120, 240 ppm) and three times of harvest (2, 3 and 4 weeks after emergence). The P adsorption isotherm for each soil was measured in 0.01 M CaCl2.All soils responded strongly to P application, the amounts required for maximum growth varying from 120 ppm on a sandy soil to 300 ppm on a moss peat. The differences in requirement were related to the P adsorption by the soil, and on all soils a solution P concentration of about 1 ppm resulted in maximum growth.The Optimal leaf P concentration in young lettuce was about 0·6%.

scholarly journals Phosphorus Requirement of Rhododendron ‘Victor’ and Cotoneaster adpressa praecox Grown in a Perlite-Peat Medium

1985 ◽  
Vol 3 (2) ◽  
pp. 63-64
Author(s):  
John R. Havis ◽  
John H. Baker
Keyword(s):  
Shoot Growth ◽  
Maximum Growth ◽  
Rooted Cuttings ◽  
Soilless Media ◽  
P Content ◽  
Growing Medium ◽  
Phosphorus Requirement ◽  
Nursery Crops ◽  
Leaf P

Rooted cuttings of Rhododendron ‘Victor’ (a PJM cultivar) and Cotoneaster adpressa praecox were grown in the greenhouse with phosphorus (P) levels ranging from 0 to 15 ppm in a perlite-peat medium. Shoot growth of Rhododendron was equal at P levels from 2.5 to 15 ppm. Maximum growth of shoots and roots of Cotoneaster was at 10 ppm. Maximum Rhododendron leaf P content occurred at 5 ppm in the medium and remained the same at higher P levels. The P content of Cotoneaster leaves increased throughout the range of P levels in the growing medium. A P level of 10 ppm in soilless media solution is suggested for most nursery crops.

scholarly journals COMPARISON OF BAND AND BROADCAST APPLICATIONS OF PHOSPHORUS ON SWEET CORN YIELD

HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 757f-758 ◽  
Author(s):  
J.M. Kemble ◽  
E.A. Guertal
Keyword(s):  
Crop Yield ◽  
Sweet Corn ◽  
Linear Increase ◽  
Soil Testing ◽  
Yield Response ◽  
Corn Yield ◽  
Fresh Weight ◽  
P Concentration ◽  
P Application ◽  
Leaf P

In 1994 and 1995, a study was conducted in Crossville, Ala., to determine if differences in leaf P concentration and crop yield occurred when P was broadcast or band-applied. Phosphorus (0, 34, 67, 101, and 134 kg P/ha) was banded (2 × 2) or broadcast and incorporated before planting. Other nutrients were applied based on current recommendations and soil testing. In 1994, as level of P increased from 0 to 150 kg P/ha, fresh weight of harvested ears increased quadratically. In 1995, fresh weight of harvested ears did not differ among broadcast treatments; however, there was a linear increase in yield among banded P treatments. There was no difference in fresh weight of harvested ears between banding and broadcasting in either year. Percent P in corn ear leaves did not differ among treatments. There was no difference in P leaf concentrations between the banded and broadcast treatments, indicating that yield response occurred because of rate of P application as opposed to method.

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 EFFECT OF RATE OF BANDED PHOSPHORUS ON SWEET CORN YIELD

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 436g-436
Author(s):  
Joseph M. Kemble ◽  
Elizabeth A. Guertal
Keyword(s):  
Crop Yield ◽  
Sweet Corn ◽  
Soil Testing ◽  
Corn Yield ◽  
Fresh Weight ◽  
P Concentration ◽  
P Application ◽  
Leaf P

In 1994, a study was conducted in Crossville, Ala., to determine if differences in leaf P concentration and crop yield occurred when P was applied as either a broadcast or banded treatment. Phosphorus (0, 34, 67, 101, and 134 kg·ha–1) was banded (2 × 2) or broadcast applied and incorporated before planting. Other nutrients were applied based on current recommendations and soil testing. As level of P increased from 0 to 134 kg·ha–1, fresh weight of harvested ears increased quadratically. There was no difference in fresh weight of harvested ears between banding and broadcasting. Yields were not maximized within the range of applied P, although it seems that yield reaches a plateau near the highest rate of applied P. Percent of P in corn ear leaves did not differ among treatments. There was no difference in P leaf concentrations between the banded and broadcast treatments, indicating that response in yield occurred due to rate of P application, not method.

Acclimation of Photosynthesis and Growth by Cotton to Elevated CO2: Interactions With Severe Phosphate Deficiency and Restricted Rooting Volume

1995 ◽  
Vol 22 (6) ◽  
pp. 955 ◽  
Author(s):  
DJ Barrett ◽  
RM Gifford
Keyword(s):  
Elevated Co2 ◽  
Phosphate Deficiency ◽  
Carbon Gain ◽  
Simple Relationship ◽  
P Concentration ◽  
Co2 Concentrations ◽  
Pot Size ◽  
Leaf P ◽  
Ambient Co2 ◽  
P Supply

Acclimation of photosynthesis and growth at three CO2 concentrations (376, 652 and 935 μmol mol-1) was examined in cotton grown under three growth-limiting phosphate (P) supplies (2.1, 6.1 and 18.2 mg P plant-1) and where biomass allocation between roots and shoots was altered by pots of three different sizes (0.32 × 10-3, 0.72 × 10-3 and 1.56 × 10-3 m3 pot-1). Phosphate supplies were chosen such that carbon gain at ambient CO2 increased linearly with P supply. Relative growth rates of these plants were 5-10-times less and photosynthetic rates 3-16-times less than for cotton supplied with abundant nutrients. Pot sizes were chosen so that root biomass and root:shoot ratios decreased with a decrease in rooting volume. Maximum carboxylation rates per unit leaf area (Vcmax) were lower in leaves grown at two elevated CO2 concentrations, compared with ambient CO2 concentrations, under all P and pot size treatments indicating that acclimation of photosynthesis had occurred. The degree of photosynthetic acclimation to elevated CO2 was not related to the degree by which whole plant carbon gain was stimulated by elevated CO2 concentration at the different P supplies, or to the degree by which allocation to root and shoots was altered by pot size. Thus there is no simple relationship between photosynthetic and growth acclimation by cotton to elevated CO2. At ambient CO2, the maximum carboxylation rate increased linearly with an increase in leaf P per unit area (mg P m-2), but rates were lower at elevated CO2 for a given P content m-2. Vcmax also increased linearly with an increase in leaf P concentration (mg P g-1 structural dry weight). However, values of Vcmax were similar for plants grown at ambient and elevated CO2, for a given P concentration. Acclimation of photosynthesis at elevated CO2 was associated with an increase in leaf starch determined 5 h into the light period. However, increased starch concentration with an increase in P supply was not associated with any decline in Vcmax.

scholarly journals Response of Young Olive Plants (Olea europaea) to Phosphorus Application

HortScience ◽  
2016 ◽  
Vol 51 (9) ◽  
pp. 1167-1170 ◽  
Author(s):  
María José Jiménez-Moreno ◽  
Ricardo Fernández-Escobar
Keyword(s):  
Shoot Growth ◽  
Phosphorus Uptake ◽  
P Uptake ◽  
Zn Deficiency ◽  
P Deficiency ◽  
P Concentration ◽  
Quadratic Response ◽  
P Application ◽  
Phosphorus Application ◽  
Leaf P

Mist-rooted ‘Picual’ olive cuttings growing in 1.1-L pots containing a mixture of washed sand and perlite were used to induce symptoms of phosphorus (P) deficiency and toxicity and to determine the nutritional status to which these symptoms occur. Plants were growing in a growth chamber at 25 °C day/15 °C night with a 14-hour photoperiod. From late spring to the autumn, plants were placed in a shade house protected from the rain. In the first experiment, plants received the application of 0, 100, 200, or 400 ppm P, and in the second experiment, 0, 12.5, 25, 50, 100, or 200 ppm P. Shoot growth was measured weekly and leaf samples were collected at different dates to determine P concentration. At the end of each experiment, plants were harvested and P was determined to obtain the P uptake by the plants. Phosphorus uptake efficiency (PUE) was estimated as PUE = (P uptake/P applied) × 100. P content increased in plants with the amount of P applied, and accumulated mainly in the roots. Vegetative growth showed a quadratic response, indicating a reduction of growth at the lowers and highest doses of P application. Leaf P concentration below or above which shoot growth was reduced was 0.11% to 0.13%. Symptoms of P deficiency and toxicity were observed in only a few plants. Leaf P concentration of deficient plants was 0.025%, and that of toxicity 0.21%. Toxicity symptoms were similar to that of zinc (Zn) deficiency. PUE was very low, 1.34% to 4.45%, suggesting the low P requirements of the olive.

scholarly journals INFLUENCE OF NITROGEN APPLICATION TIME AND PHOSPHORUS RATE ON PECAN

HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 496g-496
Author(s):  
Michael W. Smith
Keyword(s):  
Total Yield ◽  
Application Time ◽  
N Application ◽  
Soil P ◽  
P Concentration ◽  
Leaf N Concentration ◽  
P Application ◽  
Phosphorus Application ◽  
Leaf P ◽  
Plot Design

Thirty-five-year-old `Hayes' and `Patrick' trees (22 trees/ha) were fertilized with 112 kg N/ha (NH4NO3) either the second week of March or the first week of Oct each year. Phosphorus was applied (broadcast) during March 1986 and again during May 1989 at 0 or 244 kg P/ha. Treatments were arranged in a split-split-plot design with four single-tree replications. Leaf N concentration and the number of shoots/1-year-old shoot were not affected by N application time, and the effect on shoot length was inconsistent. Total yield and annual yield three of five years were greatest from `Hayes' when N was applied during Oct rather than March. Yield of `Patrick' was unaffected by time of N application. Phosphorus application increased soil P up to 20 cm deep, and leaf P concentration was increased three of five years in `Hayes' and two of five years in `Patrick'. Shoot growth, number of new shoots, nut size, kernel percentage, and yield were generally not affected by P application.

scholarly journals Time of Nitrogen Application and Phosphorus Effects on Growth, Yield, and Fruit Quality of Pecan

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 532-534 ◽  
Author(s):  
Michael W. Smith ◽  
Becky Cheary ◽  
Becky Carroll
Keyword(s):  
Shoot Growth ◽  
Growth Yield ◽  
Application Time ◽  
Cumulative Yield ◽  
N Application ◽  
P Concentration ◽  
P Application ◽  
Phosphorus Application ◽  
Leaf P

March vs. October N applications in factorial combination with two P rates were evaluated on two pecan [Carya illinoinensis (Wangenh.) C. Koch] cultivars. Leaf N concentrations were not affected by N application time. However, yield of `Hayes' was increased during 4 of 7 years and cumulative yield was increased 37% when N was applied during October compared to March. Yield of `Patrick' and individual nut weight and kernel percentage of `Hayes' and `Patrick' were not affected by N application time. Phosphorus application increased leaf P concentration 5 of 7 years during the study. Shoot growth, yield, individual nut weight, and kernel percentage were not affected by P application.

Sex-specifically responsive strategies to phosphorus availability combined with different soil nitrogen forms in dioecious Populus cathayana

2021 ◽  
Author(s):  
Xiucheng Liu ◽  
Yuting Wang ◽  
Shuangri Liu ◽  
Miao Liu
Keyword(s):  
Root Length ◽  
Root Length Density ◽  
Specific Root Length ◽  
P Uptake ◽  
Root Tip ◽  
P Availability ◽  
P Deficiency ◽  
Populus Cathayana ◽  
Leaf P ◽  
P Supply

Abstract Aims Phosphorus (P) availability and efficiency are especially important for plant growth and productivity. However, the sex-specific P acquisition and utilization strategies of dioecious plant species under different N forms are not clear. Methods This study investigated the responsive mechanisms of dioecious Populus cathayana females and males based on P uptake and allocation to soil P supply under N deficiency, nitrate (NO3 −) and ammonium (NH4 +) supply. Important Findings Females had a greater biomass, root length density (RLD), specific root length (SRL) and shoot P concentration than males under normal P availability with two N supplies. NH4 + supply led to higher total root length, RLD and SRL but lower root tip number than NO3 − supply under normal P supply. Under P deficiency, males showed a smaller root system but greater photosynthetic P availability and higher leaf P remobilization, exhibiting a better capacity to adaptation to P-deficiency than females. Under P deficiency, NO3 − supply increased leaf photosynthesis and PUE but reduced RLD and SRL in females while males had higher leaf P redistribution and photosynthetic PUE than NH4 + supply. Females had a better potentiality to cope with P deficiency under NO3 − supply than NH4 + supply; the contrary was true for males. These results suggest that females may devote to increase in P uptake and shoot P allocation under normal P availability, especially under NO3 − supply, while males adopt more efficient resource use and P remobilization to maximum their tolerance to P-deficiency.

The effects of grazing on the phosphorus requirement of an annual pasture

1971 ◽  
Vol 22 (1) ◽  
pp. 81 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes
Keyword(s):  
Subterranean Clover ◽  
Growing Season ◽  
Maximum Growth ◽  
Grazing Pressure ◽  
Light Interception ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Phosphorus Requirement ◽  
Root Size

The applied phosphorus requirement of a pasture sown to subterranean clover was measured with and without grazing. Under moderate grazing pressure, in the year of establishment, the pasture required about 50 % more phosphorus than when ungrazed. In the following season, at a higher stocking rate, the grazed areas needed twice as much phosphorus as the ungrazed to make 90% of their maximum growth. In both years this difference in requirement between stocked and unstocked treatments was present throughout the growing season. Increased phosphorus requirement under grazing is associated with the need for greater uptake of phosphorus under conditions where redistribution of absorbed phosphorus within the plant is prevented by defoliation. It does not appear to be due to effects of defoliation on root size. Nor does it depend on differential light interception or on changes in botanical composition.

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