Altitudinal effects on leaf traits and shoot growth of Betulaplatyphylla var. japonica

1995 ◽  
Vol 25 (11) ◽  
pp. 1881-1885 ◽  
Author(s):  
Gaku Kudo
Keyword(s):  
Shoot Growth ◽  
Leaf Size ◽  
Leaf Traits ◽  
Growing Season ◽  
Leaf Nitrogen ◽  
Leaf Life Span ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Lower Site ◽  
Leaf N

Leaf demography, shoot growth, and seasonal changes of leaf size, specific leaf area, and leaf nitrogen (N) concentration of Betulaplatyphylla var. japonica Hara were compared at two altitudes (140 and 700 m above sea level). At the higher site, where the length of growing season was restricted, leaf life-span was shorter and leaf N concentration was higher throughout the growing season than at the lower site. Leaf size did not differ between sites. Production of short-lived and high N concentration leaves was considered adaptive under the condition of short growing season. At the higher site, N was translocated from senescing early leaves to late leaves in mid-September, whereas a significant increase in late leaf N concentration was not observed at the lower site. There were no differences in shoot growth, bud size, late leaf number on long shoots between sites, probably because of effective N use at the higher site.

Optical sensing estimation of leaf nitrogen concentration in maize across a range of water-stress levels

2011 ◽  
Vol 62 (6) ◽  
pp. 474 ◽  
Author(s):  
Tong-Chao Wang ◽  
B. L. Ma ◽  
You-Cai Xiong ◽  
M. Farrukh Saleem ◽  
Feng-Min Li
Keyword(s):  
Water Stress ◽  
Vegetation Index ◽  
Optical Sensing ◽  
Leaf Nitrogen ◽  
Growth Stages ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Chlorophyll Index ◽  
Plant Moisture ◽  
Leaf N

Optical sensing techniques offer an instant estimation of leaf nitrogen (N) concentration during the crop growing season. Differences in plant-moisture status, however, can obscure the detection of differences in N levels. This study presents a vegetation index that robustly measures differences in foliar N levels across a range of plant moisture levels. A controlled glasshouse study with maize (Zea mays L.) subjected to both water and N regimes was conducted in Ottawa, Canada. The purpose of the study was to identify spectral waveband(s), or indices derived from different wavebands, such as the normalised difference vegetation index (NDVI), that are capable of detecting variations in leaf N concentration in response to different water and N stresses. The experimental design includes three N rates and three water regimes in a factorial arrangement. Leaf chlorophyll content and spectral reflectance (400–1075 nm) were measured on the uppermost fully expanded leaves at the V6, V9 and V12 growth stages (6th, 9th and 12th leaves fully expanded). N concentrations of the same leaves were determined using destructive sampling. A quantitative relationship between leaf N concentration and the normalised chlorophyll index (normalised to well fertilised and well irrigated plants) was established. Leaf N concentration was also a linear function (R2 = 0.9, P < 0.01) of reflectance index (NDVI550, 760) at the V9 and V12 growth stages. Chlorophyll index increased with N nutrition, but decreased with water stress. Leaf reflectance at wavebands of 550 ± 5 nm and 760 ± 5 nm were able to separate water- and N-stressed plants from normal growing plants with sufficient water and N supply. Our results suggest that NDVI550, 760 and normalised chlorophyll index hold promise for the assessment of leaf N concentration at the leaf level of both normal and water-stressed maize plants.

scholarly journals Down-Regulation of Photosynthesis to Elevated CO2 and N Fertilization in Understory Fraxinus rhynchophylla Seedlings

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1197
Author(s):  
Siyeon Byeon ◽  
Kunhyo Kim ◽  
Jeonghyun Hong ◽  
Seohyun Kim ◽  
Sukyung Kim ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
N Fertilization ◽  
Leaf Nitrogen ◽  
N Availability ◽  
Down Regulation ◽  
Leaf Production ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Regulation Of Photosynthesis ◽  
Leaf N

(1) Background: Down-regulation of photosynthesis has been commonly reported in elevated CO2 (eCO2) experiments and is accompanied by a reduction of leaf nitrogen (N) concentration. Decreased N concentrations in plant tissues under eCO2 can be attributed to an increase in nonstructural carbohydrate (NSC) and are possibly related to N availability. (2) Methods: To examine whether the reduction of leaf N concentration under eCO2 is related to N availability, we investigated understory Fraxinus rhynchophylla seedlings grown under three different CO2 conditions (ambient, 400 ppm [aCO2]; ambient × 1.4, 560 ppm [eCO21.4]; and ambient × 1.8, 720 ppm [eCO21.8]) and three different N concentrations for 2 years. (3) Results: Leaf and stem biomass did not change under eCO2 conditions, whereas leaf production and stem and branch biomass were increased by N fertilization. Unlike biomass, the light-saturated photosynthetic rate and photosynthetic N-use efficiency (PNUE) increased under eCO2 conditions. However, leaf N, Rubisco, and chlorophyll decreased under eCO2 conditions in both N-fertilized and unfertilized treatments. Contrary to the previous studies, leaf NSC decreased under eCO2 conditions. Unlike leaf N concentration, N concentration of the stem under eCO2 conditions was higher than that under ambient CO2 (4). Conclusions: Leaf N concentration was not reduced by NSC under eCO2 conditions in the understory, and unlike other organs, leaf N concentration might be reduced due to increased PNUE.

scholarly journals Leaf Nitrogen Status on Yield and Quality of Roses

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 564C-564b
Author(s):  
Raul I. Cabrera
Keyword(s):  
Experimental Period ◽  
Leaf Nitrogen ◽  
Stem Length ◽  
Yield And Quality ◽  
Leaf Chlorophyll ◽  
N Concentration ◽  
Biomass Yields ◽  
Leaf N Concentration ◽  
Plant Yields ◽  
Leaf N

The establishment of critical tissue N levels for greenhouse rose production has been primarily based on visual symptoms of N deficiency, with relatively less consideration to yield parameters. This work examined the relationship between rose leaf N concentration and flower yield and quality. Container-grown `Royalty' rose plants were irrigated for 13 months with complete nutrient solutions containing N concentrations of 30, 60, 90, 120, 150 and 220 mg·L–1. Optimum flower and dry biomass yields, stem length, and stem weights were obtained in plants irrigated with 90 mg·L–1 N. Leaf N concentrations increased asymptotically with N applications, stabilizing at N concentrations >90 mg·L–1. Time of the year had an effect on overall leaf N concentrations, with higher values observed in the winter, and lower values in the summer. Leaf N concentrations were linearly, and significantly, correlated with leaf chlorophyll content and leaf color attributes (hue, chroma, and value). Quadratic relationships between leaf N concentration and rose plant yields were observed only for the second half of the experimental period, and depicted an apparent, and striking, plant control over tissue N status. In addition, these relationships indicated that optimum plant yields were possible during spring and summer with leaf N concentrations below the recommended critical level of 3% (as low as 2.4% to 2.5%). These results suggest that leaf N concentration per se is not a dependable indicator of rose productivity.

scholarly journals Using SPAD-502 Values to Assess the Nitrogen Status of Apple Trees

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 508-512 ◽  
Author(s):  
Denise Neilsen ◽  
Eugene J. Hogue ◽  
Gerald H. Neilsen ◽  
Peter Parchomchuk
Keyword(s):  
Growing Season ◽  
Sampling Time ◽  
Nutrition Programs ◽  
N Concentration ◽  
Leaf N Concentration ◽  
N Rates ◽  
Spad Readings ◽  
Spad Meter ◽  
Leaf N

Four apple (Malus domestica Borkh) cultivars (`Fuji', `Spartan', `Fiesta', and `Gala') on Malling 9 (M.9) rootstock were grown in the field with three N rates (5, 20, and 35 g N/tree per year), supplied as Ca(NO3)2, and fertigated daily for 9 weeks. In the second year, leaf SPAD readings (chlorophyll readings obtained with the Minolta-502 SPAD meter) increased over the growing season for all cultivars, and leaf N decreased. Leaf SPAD and leaf N measurements increased in response to N fertigation rate at all sampling times. `Gala' consistently had lower SPAD readings than the other cultivars, and, with the exception of the first sampling time, `Fuji' had higher and `Fiesta' lower leaf N concentrations than other cultivars. There were strong relationships between leaf N concentration and SPAD readings for all cultivars until mid-July (r2 = 0.44 to 0.89), but not later in the growing season. Differences in SPAD readings and leaf N concentration due to cultivar and over time were as great as those due to N treatments, indicating that in the future, determination of critical SPAD values for apple leaves must be standardized for cultivar and sampling time. SPAD readings could be used to assess the need for N early in the growing season in fertigated orchards where rapid changes in nutrition programs can be undertaken readily.

Interactions Between Rising CO2 Concentration and Nitrogen Supply in Cotton. I. Growth and Leaf Nitrogen Concentration

1996 ◽  
Vol 23 (2) ◽  
pp. 119 ◽  
Author(s):  
GS Rogers ◽  
PJ Milham ◽  
MC Thibaud ◽  
JP Conroy
Keyword(s):  
Leaf Area ◽  
Elevated Co2 ◽  
Shoot Growth ◽  
High Co2 ◽  
N Supply ◽  
Co2 Concentrations ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Sink Development ◽  
Leaf N

The influence of sink development on the response of shoot growth in cotton (Gossypium hirsutum L. cv. Siokra BT1-4) was investigated by growing plants at three levels of CO2=2 concentration: 350 (ambient), 550 and 900 μL L-1 and six levels of nitrogen (N) supply ranging from deficient to excess (0-133 mg N kg-1 soil week-1). Changes in leaf N concentration were also investigated. At 59 days after sowing, there was an average 63% increase in shoot growth at 550 μL CO2 L-1 compared with ambient CO2-grown plants, with no significant growth increase at 900 μL CO2 L-1 and, this response was closely matched by sink development (flower number and stem weight). Low N supply restricted the responses of both sink development and shoot growth to high CO2. At elevated CO2, leaf N concentration was reduced by an average 27% at low to adequate N supply. The high CO2-induced reduction in leaf N concentration, however, disappeared when the N supply was increased to a high level of 133 mg N kg-1 soil week-1. These CO2 effects on leaf N concentration were smaller when N was expressed per unit leaf area, apparently due to a combination of the effects of elevated CO2 or high N supply reducing specific leaf area and, to an N uptake limitation at low to moderate levels of N supply. The critical foliar N concentrations (leaf N concentration at 90% of maximum shoot growth) were reduced from 42 to 38 and 36 mg g-1 when CO2 concentrations were increased from 350 to 550 and 900 μL L-1 respectively, indicating that changes in fertiliser management may be required under changing CO2 concentrations.

scholarly journals Pest Damage to Pecan is Affected by Irrigation, Nitrogen Application, and Fruit Load

HortScience ◽  
2000 ◽  
Vol 35 (4) ◽  
pp. 669-672 ◽  
Author(s):  
Bruce W. Wood ◽  
Charles C. Reilly
Keyword(s):  
Shoot Growth ◽  
Cultural Practices ◽  
Water Status ◽  
Leaf Water ◽  
Leaf Water Status ◽  
Crop Load ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Arthropod Pests ◽  
Leaf N

Orchard trees of pecan [Carya illinoinensis (Wangenh.) K. Koch] were subjected to combinations of cultural practices inducing differential physiological states so as to assess the potential for culture-related impact on damage to trees by key arthropod pests. Leaf N concentration, leaf water status, and crop load all affected foliar damage by black pecan aphids [BPA; Melanocallis caryaefoliae (Davis)] and pecan leaf scorch mite [PLSM; Eotetranychus hicoriae (McGregor)], as well as second-flush shoot growth. Damage to first-flush foliage in the late season by BPA generally diminished as leaf water status and leaf N concentration increased, but intensified with a reduction in crop load. Conversely, foliage damage by PLSM increased with elevated leaf water status and N concentration, but was unaffected by crop load. First- and second-order interactions for all combinations of cultural treatments conferring differential physiological states affected damage by pests and induction of second-flush shoot growth. Arthropod-induced defoliation on trees receiving highly favorable cultural practices—those producing high leaf N, high leaf water availability, and low crop load—was greater than on trees receiving minimal or lesser cultural inputs. Thus, cultural practices influencing leaf water status, N status, or crop load potentially act and interact to produce both desirable and undesirable side-effects on damage incurred by certain arthropod pests and therefore merit consideration in efforts to develop improved integrated pest management strategies.

Quantifying the nonlinearity in chlorophyll meter response to corn leaf nitrogen concentration

1995 ◽  
Vol 75 (1) ◽  
pp. 179-182 ◽  
Author(s):  
L. M. Dwyer ◽  
D. W. Stewart ◽  
E. Gregorich ◽  
A. M. Anderson ◽  
B. L. Ma ◽  
...  
Keyword(s):  
Growth Stage ◽  
Nitrogen Concentration ◽  
Leaf Nitrogen ◽  
Growth Stages ◽  
Concentration Data ◽  
Chlorophyll Meter ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Non Destructive ◽  
Leaf N

Chlorophyll meters have been used to provide a rapid non-destructive method to estimate corn leaf nitrogen (N) concentration, although meter readings plateau at high leaf N levels. Paired chlorophyll meter and leaf N concentration data were obtained for ear level leaves at growth stages ranging from 3 wk before anthesis to 5 wk after anthesis over a 2-yr period at Ottawa, Ontario. Separate quadratic-plus-plateau models best represented chlorophyll meter response to leaf N concentration for pre-anthesis, early grain-fill and late grain-fill stages; chlorophyll meter readings corresponding to the beginning of the plateau increased at later growth stages. Leaf N concentration was estimated well from chlorophyll meter readings up to the plateau range using growth stage specific functions (R2 ≥ 0.77) but chlorophyll meter readings beyond the plateau should not be used to estimate leaf N concentration. Key words: Chlorophyll meter calibration, maize

scholarly journals Indirect Estimations of Lentil Leaf and Plant N by SPAD Chlorophyll Meter

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Hossein Zakeri ◽  
Jeff Schoenau ◽  
Albert Vandenberg ◽  
Mohammadreza Tayfeh Aligodarz ◽  
Rosalind A. Bueckert
Keyword(s):  
Leaf Nitrogen ◽  
Plant Age ◽  
Rbf Neural Networks ◽  
Chlorophyll Meter ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Independent Variable ◽  
Relationship Of ◽  
The Relationship ◽  
Leaf N

A Soil Plant Analysis Development (SPAD) chlorophyll meter can be used to screen for leaf nitrogen (N) concentration in breeding programs. Lentil (Lens culinarisL.) cultivars were grown under varied N regimes, SPAD chlorophyll meter readings (SCMR) were recorded from the cultivars leaves, and leaf N concentration was measured by combustion. Linear regression and the nonlinear Radial Basis Functions (RBF) neural networks models were employed to estimate leaf N concentration (LNC) based on the SCMR values. The closest estimates of LNC were obtained from the multivariate models in which the combination of plant age, leaf thickness, and SCMR was employed as the independent variable. In comparison, SCMR as the single independent variable in both models estimated less than 50% of LNC variations. The results showed significant effects of soil moisture and plant age on the association of LNC –SCMR as well as the relationship of LNC with plant N, grain yield, and days to maturity. However, the effect of cultivar on the measured variables was negligible. Although lentil N can be diagnosed by comparing SCMR values of the crop with those from a well-fertilized (N fixing) plot, the results did not support using SPAD chlorophyll meter for screening lentil LNC.

scholarly journals Nitrogen use efficiency and critical leaf N concentration of Aloe vera in urea and diammonium phosphate amended soil

Heliyon ◽  
2020 ◽  
Vol 6 (12) ◽  
pp. e05718
Author(s):  
Md. Akhter Hossain Chowdhury ◽  
Taslima Sultana ◽  
Md. Arifur Rahman ◽  
Tanzin Chowdhury ◽  
Christian Ebere Enyoh ◽  
...  
Keyword(s):  
Nitrogen Use Efficiency ◽  
Aloe Vera ◽  
Diammonium Phosphate ◽  
Nitrogen Use ◽  
N Concentration ◽  
Leaf N Concentration ◽  
Use Efficiency ◽  
Leaf N ◽  
Amended Soil

scholarly journals Estimating Plant Nitrogen Concentration of Maize Using a Leaf Fluorescence Sensor across Growth Stages

2020 ◽  
Vol 12 (7) ◽  
pp. 1139
Author(s):  
Rui Dong ◽  
Yuxin Miao ◽  
Xinbing Wang ◽  
Zhichao Chen ◽  
Fei Yuan ◽  
...  
Keyword(s):  
Precision Agriculture ◽  
Fluorescence Sensor ◽  
Accurate Estimation ◽  
Growth Stages ◽  
Fluorescence Sensors ◽  
N Application ◽  
N Concentration ◽  
Leaf N Concentration ◽  
N Status ◽  
Leaf N

Nitrogen (N) is one of the most essential nutrients that can significantly affect crop grain yield and quality. The implementation of proximal and remote sensing technologies in precision agriculture has provided new opportunities for non-destructive and real-time diagnosis of crop N status and precision N management. Notably, leaf fluorescence sensors have shown high potential in the accurate estimation of plant N status. However, most studies using leaf fluorescence sensors have mainly focused on the estimation of leaf N concentration (LNC) rather than plant N concentration (PNC). The objectives of this study were to (1) determine the relationship of maize (Zea mays L.) LNC and PNC, (2) evaluate the main factors influencing the variations of leaf fluorescence sensor parameters, and (3) establish a general model to estimate PNC directly across growth stages. A leaf fluorescence sensor, Dualex 4, was used to test maize leaves with three different positions across four growth stages in two fields with different soil types, planting densities, and N application rates in Northeast China in 2016 and 2017. The results indicated that the total leaf N concentration (TLNC) and PNC had a strong correlation (R2 = 0.91 to 0.98) with the single leaf N concentration (SLNC). The TLNC and PNC were affected by maize growth stage and N application rate but not the soil type. When used in combination with the days after sowing (DAS) parameter, modified Dualex 4 indices showed strong relationships with TLNC and PNC across growth stages. Both modified chlorophyll concentration (mChl) and modified N balance index (mNBI) were reliable predictors of PNC. Good results could be achieved by using information obtained only from the newly fully expanded leaves before the tasseling stage (VT) and the leaves above panicle at the VT stage to estimate PNC. It is concluded that when used together with DAS, the leaf fluorescence sensor (Dualex 4) can be used to reliably estimate maize PNC across growth stages.

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