scholarly journals CORRELATIONS OF CITRUS LEAF CHLOROPHYLL WITH LEAF MINERAL CONTENT

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 669c-669
Author(s):  
Robert E. Rouse
Keyword(s):  
Chlorophyll Content ◽  
Mineral Content ◽  
Nutrient Elements ◽  
Mineral Analysis ◽  
Chlorophyll Meter ◽  
Standard Curve ◽  
Leaf Chlorophyll ◽  
Citrus Leaves ◽  
Relationship Of ◽  
The Relationship

The Minolta chlorophyll meter SPAD-502 (Minolta Camera Company, 101 Williams Drive, NJ 07446, USA) has been found to be a quick, accurate, simple, and nondestructive way to determine chlorophyll content in citrus leaves and a standard curve had been developed. The SPAD-502 chlorophyll meter was used to measure chlorophyll content in citrus leaves of ten varieties on three rootstocks. Leaf mineral analysis was then determined on these leaves for N, P, K, Mg, Mn, Zn, Fe, Cu and Ca. Correlation r values were generally low and not significant for most nutrient elements but were highest for Fe and Ca. The relationship of leaf nutrient levels and chlorophyll meter readings are not understood. The usefulness of the SPAD chlorophyll meter for determining mineral content in citrus leaves is not yet known.

scholarly journals A NONDESTRUCTIVE METHOD TO MEASURE CHLOROPHYLL IN CITRUS LEAVES

HortScience ◽  
1991 ◽  
Vol 26 (6) ◽  
pp. 694A-694
Author(s):  
Robert E. Rouse ◽  
Sandra P. Perez ◽  
Sally B. Davenport
Keyword(s):  
Chlorophyll Content ◽  
Sweet Orange ◽  
Nondestructive Method ◽  
Chlorophyll Meter ◽  
Standard Curve ◽  
Citrus Leaves ◽  
Chlorophyll Extraction

The Minolta chlorophyll meter SPAD-502 (Minolta Camera Company, 101 Williams Drive, NJ 07446, USA) was evaluated as an accurate, nondestructive means to measure chlorophyll content in citrus leaves. Meter readings from leaves of sweet orange and grapefruit citrus cultivars were used to develop a standard curve for citrus. A significant correlation value of 0.96 was calculated between the chlorophyll meter readings and actual chlorophyll extraction levels. The development of a standard curve using the SPAD-502 chlorophyll meter had not been established on citrus. The SPAD-502 chlorophyll meter proved to be a quick, accurate, simple, and nondestructive way to determine chlorophyll content in citrus leaves.

scholarly journals Effects of Crop Leaf Angle on LAI-Sensitive Narrow-Band Vegetation Indices Derived from Imaging Spectroscopy

2018 ◽  
Vol 8 (9) ◽  
pp. 1435 ◽  
Author(s):  
Xiaochen Zou ◽  
Iina Haikarainen ◽  
Iikka Haikarainen ◽  
Pirjo Mäkelä ◽  
Matti Mõttus ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Vegetation Indices ◽  
Imaging Spectroscopy ◽  
Leaf Angle ◽  
Field Crops ◽  
Leaf Chlorophyll ◽  
Simple Ratio ◽  
The Relationship

Leaf area index (LAI) is an important biophysical variable for understanding the radiation use efficiency of field crops and their potential yield. On a large scale, LAI can be estimated with the help of imaging spectroscopy. However, recent studies have revealed that the leaf angle greatly affects the spectral reflectance of the canopy and hence imaging spectroscopy data. To investigate the effects of the leaf angle on LAI-sensitive narrowband vegetation indices, we used both empirical measurements from field crops and model-simulated data generated by the PROSAIL canopy reflectance model. We found the relationship between vegetation indices and LAI to be notably affected, especially when the leaf mean tilt angle (MTA) exceeded 70 degrees. Of the indices used in the study, the modified soil-adjusted vegetation index (MSAVI) was most strongly affected by leaf angles, while the blue normalized difference vegetation index (BNDVI), the green normalized difference vegetation index (GNDVI), the modified simple ratio using the wavelength of 705 nm (MSR705), the normalized difference vegetation index (NDVI), and the soil-adjusted vegetation index (SAVI) were only affected for sparse canopies (LAI < 3) and MTA exceeding 60°. Generally, the effect of MTA on the vegetation indices increased as a function of decreasing LAI. The leaf chlorophyll content did not affect the relationship between BNDVI, MSAVI, NDVI, and LAI, while the green atmospherically resistant index (GARI), GNDVI, and MSR705 were the most strongly affected indices. While the relationship between SR and LAI was somewhat affected by both MTA and the leaf chlorophyll content, the simple ratio (SR) displayed only slight saturation with LAI, regardless of MTA and the chlorophyll content. The best index found in the study for LAI estimation was BNDVI, although it performed robustly only for LAI > 3 and showed considerable nonlinearity. Thus, none of the studied indices were well suited for across-species LAI estimation: information on the leaf angle would be required for remote LAI measurement, especially at low LAI values. Nevertheless, narrowband indices can be used to monitor the LAI of crops with a constant leaf angle distribution.

THE RELATIONSHIP OF BONE MINERAL CONTENT AND PHYSICAL ACTIVITY IN WOMEN OVER THE AGE OF THIRTY

1983 ◽  
Vol 15 (2) ◽  
pp. 149 ◽  
Author(s):  
R. J. Stillman ◽  
T. G. Lohman ◽  
M. H. Slaughter ◽  
B. H. Massey
Keyword(s):  
Physical Activity ◽  
Bone Mineral Content ◽  
Bone Mineral ◽  
Mineral Content ◽  
Relationship Of ◽  
The Relationship

Influences of Physical Fitness on Bone Mass in Women With Fibromyalgia

2015 ◽  
Vol 32 (2) ◽  
pp. 125-136 ◽  
Author(s):  
Alba Gómez-Cabello ◽  
Germán Vicente-Rodríguez ◽  
Isabel Navarro-Vera ◽  
Diana Martinez-Redondo ◽  
Carmen Díez-Sánchez ◽  
...  
Keyword(s):  
Bone Mass ◽  
Physical Fitness ◽  
Mineral Content ◽  
Handgrip Strength ◽  
Quadriceps Strength ◽  
Cardiovascular Fitness ◽  
Whole Body ◽  
Control Group ◽  
Relationship Of ◽  
The Relationship

The aim of this study was to provide information about the relationship of bone mineral content (BMC) and density (BMD) with some physical-fitness-related variables in a sample of women with fibromyalgia (FM) and age-matched women without FM. Twenty-eight women clinically diagnosed with FM (age 51.1 ± 8.4 yr, M ± SD) and 22 age-matched controls participated in the study. Whole-body BMC and BMD, lean mass, handgrip strength, quadriceps strength, and cardiovascular fitness were measured in all participants. The association between physical-fitness variables and bone-related variables was tested by linear regression controlling for body weight as a possible confounder. There were no differences in BMC or BMD between groups. Women with FM had lower values of handgrip strength, quadriceps strength, and VO2peak than the control group. Handgrip strength and aerobic capacity were associated with BMC and BMD and quadriceps strength was associated with BMD in women with FM; however, only VO2peak was associated with BMC in the group of women without FM. Bone mass of women with FM may be more susceptible to changes in physical fitness than that of the women without fibromyalgia.

scholarly journals Evaluation of SPAD and LCC based nitrogen management in rice (Oryza sativa L.)

1970 ◽  
Vol 34 (4) ◽  
pp. 661-672 ◽  
Author(s):  
M Sh Islam ◽  
MSU Bhuiya ◽  
S Rahman ◽  
MM Hussain
Keyword(s):  
Chlorophyll Content ◽  
Lower Amount ◽  
Flower Initiation ◽  
Plant Analysis ◽  
Rice Varieties ◽  
Chlorophyll Contents ◽  
Spad Value ◽  
Leaf Chlorophyll ◽  
Relationship Of ◽  
Nitrogen Contents

A study was conducted during Boro and T. Aman seasons of 2002 at Bangladesh Rice Research Institute (BRRI), Gazipur to see the relationship of SPAD (Soil plant analysis development) reading with chlorophyll and N contents of leaves and to determine the critical LCC value for rice crops. Hybrid varieties Sonarbangla-1 and BRRI hybrid dhan0l were used for both rice crops and BRRI dhan29 and BRRI dhan31 were used as checks for Boro and T. Aman crops, respectively. Sonarbangla-1, BRRI hybrid dhan0l and BRRI dhan29 had similar leaf chlorophyll contents in Boro season. The maximum chlorophyll content (1.6-1.8 mg/g leaf) was observed at 39-42 soil plant analysis development (SPAD) value. In T. Aman season, the inbred BRRI dhan3l showed lower amount of chlorophyll (1.2-1.4 mg/g leaf) at 39-42 SPAD value compared to the hybrids Sonarbangla-1 and BRRI hybrid dhan 0l. Seasonal variation in chlorophyll content between Sonarbangla-1 and BRRI hybrid dhan0l was not large. Relationship between SPAD value and chlorophyll content was very close (R2 =>0.8) at panicle initiation and flower initiation stages for all the varieties. Similar relationship was also observed in case of SPAD value and nitrogen content in leaves. The results indicated that the rice leaves showing higher SPAD readings (>35) had higher chlorophyll and nitrogen contents. The adjusted critical LCC values were 3.0 for Boro and 3.5 for T. Aman seasons for all rice varieties. Key Words: Chlorophyll; nitrogen.DOI: 10.3329/bjar.v34i4.5841Bangladesh J. Agril. Res. 34(4) : 661-672, December 2009

Effect of different physiological traits on grain yield in barley grown under irrigated and terminal water deficit conditions

2010 ◽  
Vol 148 (3) ◽  
pp. 319-328 ◽  
Author(s):  
A. GONZÁLEZ ◽  
V. BERMEJO ◽  
B. S. GIMENO
Keyword(s):  
Water Deficit ◽  
Chlorophyll Concentration ◽  
Net Photosynthesis ◽  
Physiological Traits ◽  
Breeding Lines ◽  
Terminal Drought ◽  
Leaf Chlorophyll ◽  
Drought Tolerant ◽  
Relationship Of ◽  
The Relationship

SUMMARYDrought is the main factor limiting the productivity of crops in Mediterranean areas. The introduction of physiological traits into crops that improve their tolerance to drought is necessary if yields under these conditions are to be efficiently improved. The effect of drought on different gas exchange variables, i.e. net photosynthesis (A), stomatal conductance (gs) and leaf chlorophyll concentration (Chl), and the relationship of these variables with yield were studied in 12 barley genotypes grown under irrigated and terminal drought conditions. The variable most sensitive to water deficit was gs (mean reduction 43% with respect to control conditions), followed by A (mean reduction 34%). The mean reduction of yield by terminal drought was 27%. A significant correlation was seen between these physiological traits and yield. The effect of water deficit on A, gs and Chl was smaller in the breeding lines than in the traditional varieties assayed, in agreement with the results found for yield. These results suggest a potential indirect selection of physiological characteristics in these breeding lines that allow greater tolerance to drought. The response of the different genotypes examined was not homogeneous across all the variables analysed. This variability is important in programmes aiming to obtain drought-tolerant genotypes via the optimization of traits such as those above.

scholarly journals Growing Conditions Alter the Relationship Between SPAD-501 Values and Apple Leaf Chlorophyll

HortScience ◽  
1990 ◽  
Vol 25 (3) ◽  
pp. 330-331 ◽  
Author(s):  
Richard J. Campbell ◽  
Kendrick N. Mobley ◽  
Richard P. Marini ◽  
Douglas G. Pfeiffer
Keyword(s):  
Chlorophyll Content ◽  
Malus Domestica ◽  
Regression Models ◽  
Total Chlorophyll ◽  
Total Chlorophyll Content ◽  
Leaf Chlorophyll ◽  
Growing Conditions ◽  
The Relationship

The relationship between SPAD-501 meter readings (SPAD) and total chlorophyll content (TCHL) was evaluated for `Delicious' apple (Malus domestica Borkh.) leaves grown in various environments. Regression models were developed between SPAD and TCHL for each of six separate experiments and were evaluated for statistical coincidence. SPAD was linearly related in a positive manner to TCHL in five of the six experiments; however, models differed between experiments, particularly between field- and greenhouse-grown trees. Thus, the relationship between SPAD and TCHL must be determined for each experiment.

Sign in / Sign up

Export Citation Format

Share Document