scholarly journals Relating X-band SAR Backscattering to Leaf Area Index of Rice in Different Phenological Phases

2019 ◽  
Vol 11 (12) ◽  
pp. 1462 ◽  
Author(s):  
Sonia Asilo ◽  
Andrew Nelson ◽  
Kees de Bie ◽  
Andrew Skidmore ◽  
Alice Laborte ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Linear Relationship ◽  
Leaf Area ◽  
P Value ◽  
Area Index ◽  
Dynamic Relationship ◽  
Reproductive Phase ◽  
X Band ◽  
Relationship Of ◽  
The Relationship

The objective of this study is to provide complete information on the dynamic relationship between X-band (3.11 cm) backscattering intensity (σ°) and rice crop’s leaf area index (LAI) at all growth phases. Though the relationship between X-band σ° and LAI has been previously explored, details on the relationship at the reproductive phase remain unstudied. LAI at the reproductive phase is important particularly at the heading stage where LAI reaches its maximum as it is closely related to grain yield, and at flowering stage where the total leaf area affects the amount of photosynthates. Therefore, this study examined the relationship of increasing LAI (vegetative to reproductive phase) and decreasing LAI (ripening phase) with TerraSAR-X (TSX) ScanSAR (3.11 cm) σ° at HH polarisation and 45° incidence angle. The results showed a statistically significant (R2 = 0.51, p value < 0.001) non-linear relationship of LAI with σ° at the vegetative to reproductive phase while no significant linear relationship was found at the ripening phase. This study completes the response curve of X-band σ° to LAI by filling in the information on the reproductive phase which more accurately characterises the dynamic relationship between the rice crop’s LAI and X-band’s σ°. This contributes to improved knowledge on the use of X-band data for estimating LAI for the whole crop cycle which is essential for the modelling of crop growth and estimation of yield.

On the relationship of NDVI with leaf area index in a deciduous forest site

2005 ◽  
Vol 94 (2) ◽  
pp. 244-255 ◽  
Author(s):  
Quan Wang ◽  
Samuel Adiku ◽  
John Tenhunen ◽  
André Granier
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Deciduous Forest ◽  
Forest Site ◽  
Area Index ◽  
Relationship Of ◽  
The Relationship

scholarly journals Nutrient management on leaf area index of potato-mungbean- T. aman rice cropping pattern

2015 ◽  
Vol 39 (3) ◽  
pp. 515-527 ◽  
Author(s):  
MAH S Jahan ◽  
MAR Sarkar ◽  
M Salim
Keyword(s):  
Leaf Area Index ◽  
Linear Relationship ◽  
Leaf Area ◽  
Nutrient Management ◽  
Agricultural Research ◽  
Management Practice ◽  
Research Centre ◽  
Cropping Pattern ◽  
Area Index ◽  
Positive Linear Relationship

A field experiment was conducted at Regional Wheat Research Centre of the Bangladesh Agricultural Research Institute, Joydebpur, Gazipur, Bangladesh for 2 consecutive years during 2006-07 and 2007-08. The objective was to find out the optimum nutrient management practice on leaf area index of each component crop of potato-mungbean-T. Aman rice cropping pattern. Twelve nutrient management treatments were tested in RCBD with 3 replications. Treatments combination based on cropping pattern were T1=HYG (0-198-44- 194-24-6-1.2 for potato; 0-24-40-48-24-3-1.2 for mungbean ; 0-80-16-44-12-2-0 for T.Aman rice ), T2=MYG (0-140-34-138-18-4.5-0.9 for potato; 0-20-36-40- 20-2-1 for mungbean ; 0-56-12-32-8-1.5-0 for T.Aman rice), T3=IPNS (10000- 168-38-170-18-6-1.2 for potato ; 5000-9-37-36-21-3-1.2 for mungbean ; 5000- 65-13-32-9-2-0 for T.Aman rice), T4=STB (0-171-40-164-22-5-1 for potato; 0- 20-36-40-22-2-1 for mungbean ; 0-68-15-37-11-2-0 for T.Aman rice), T5=FP (0- 97-16-91-0-0-0 for potato ; 0-6-5-4-0-0-0 for mungbean ; 0-39-37-12-0-0-0 for T.Aman rice), T6=CON (0-0-0-0-0-0-0 for potato, mungbean and T.Aman rice) kg/ha CDNPKSZnB, T7=HYG+CRI, T8=MYG+CRI, T9=IPNS+CRI, T10=STB+CRI, T11=FP+CRI, T12=CON+CRI for potato-mungbean T.Aman rice cropping pattern, respectively. Average of two years data showed that HYG+CRI treatment gave maximum LAI followed by HYG, IPNS+CRI, IPNS, STB+CRI, and STB treatments at 60 days after planting (DAP) for potato, at 50 days after sowing (DAS) for mungbean, at 60 days after transplanting (DAT) for T.Aman rice, respectively. For potato, there was a significant (p?0.01) and positive linear relation between the LAI at 60 DAP and the tuber yield. While there was a significant (p?0.01) and positive linear relationship between the LAI at 50 DAS and seed yield of mungbean. In case of T.Aman rice, there was a significant (p?0.05) as well as positive linear relationship between the LAI at 60 DAT and the grain yield of rice. DOI: http://dx.doi.org/10.3329/bjar.v39i3.21994 Bangladesh J. Agril. Res. 39(3): 515-527, September 2014

Relationship between tillering and leaf area index: quantifying critical leaf area index for tillering in rice

2002 ◽  
Vol 138 (3) ◽  
pp. 269-279 ◽  
Author(s):  
X. ZHONG ◽  
S. PENG ◽  
J. E. SHEEHY ◽  
R. M. VISPERAS ◽  
H. LIU
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Planting Density ◽  
Coefficient Of Determination ◽  
Area Index ◽  
N Input ◽  
Major Factors ◽  
The Relationship ◽  
Changing Light ◽  
Input Level

A field study was conducted at the International Rice Research Institute (IRRI), Philippines during the dry seasons of 1997 and 1998 under irrigated conditions. The objectives of this study were to quantify the critical leaf area index (LAIc) at which tillering stops based on the relationship between tillering rate and LAI, and to determine the effect of nitrogen (N) on LAIc in irrigated rice (Oryza sativa L.) crop. Results showed that the relative tillering rate (RTR) decreased exponentially as LAI increased at a given N input level. The coefficient of determination for the equation quantifying the RTR-LAI relationship ranged from 0·87 to 0·99. The relationship between RTR and LAI was affected by N input level, but not by planting density. The N input level had a significant effect on LAIc with a high N input level causing an increase in LAIc. Tillering stopped at LAI of 3·36 to 4·11 when N was not limiting. Under N limited conditions LAIc reduced to as low as 0·98. Transplanting spacing and number of seedlings per hill had little effect on LAIc. Results from this study suggest that LAI and plant N status are two major factors that influence tiller production in rice crops. The possibility that LAI influences tillering by changing light intensity and/or light quality at the base of the canopy where tiller buds and young tillers are located is discussed.

CANOPY CHARACTERISTICS OF CONTRASTING CLONES OF CACAO (THEOBROMA CACAO)

2002 ◽  
Vol 38 (3) ◽  
pp. 359-367 ◽  
Author(s):  
A. J. Daymond ◽  
P. Hadley ◽  
R. C. R. Machado ◽  
E. Ng
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Theobroma Cacao ◽  
Light Interception ◽  
Canopy Architecture ◽  
Mature Trees ◽  
Area Index ◽  
Mean Values ◽  
Extinction Coefficients ◽  
The Relationship

Canopy characteristics (leaf area index, fractional light interception, extinction coefficient) of mature trees of ten clonally propagated cacao cultivars were measured over a period of 14 months at an experiment site in Bahia, Brazil. Differences in leaf area index between clones became more pronounced over time. When an approximately constant leaf area index was reached (after about nine months), the leaf area index varied between clones from 2.8 to 4.5. Clonal differences in the relationship between leaf area index and fractional light interception implied differences in canopy architecture, as reflected by the range of extinction coefficients (mean values ranged from 0.63 for the clone TSH-565 to 0.82 for CC-10). The results demonstrate the potential for breeding more photosynthetically efficient cacao canopies.

Response of late-sown mustard (Brassica juncea) to irrigation and nitrogen

1994 ◽  
Vol 123 (2) ◽  
pp. 219-224 ◽  
Author(s):  
S. K. Yadav ◽  
Krishan Chander ◽  
D. P. Singh
Keyword(s):  
Leaf Area Index ◽  
Linear Relationship ◽  
Leaf Area ◽  
Brassica Juncea ◽  
Seed Yield ◽  
Light Absorption ◽  
Irrigation Treatment ◽  
Canopy Temperature ◽  
Area Index ◽  
N Treatment

SummaryThe response of late-sown mustard (Brassica juncea L.) to four rates of irrigation (ratio of irrigation depth to cumulative pan evaporation, ID:CPE = 0·2, 0·4, 0·6 and 0·8) and nitrogen (0, 30, 60 and 90 kg/ha) was investigated at Haryana Agricultural University, India, in the winter seasons of 1986/87 and 1987/88. Increases in the amounts of water and N fertilizer applied increased leaf water potential, stomatal conductance, light absorption, leaf area index, seed yield and evapotranspiration and decreased canopy temperature. Water-use efficiency was highest for the 0·4 ID:CPE irrigation treatment in both seasons, and for the 60 kg N/ha N treatment in 1986/87 and the 90 kg N/ha treatment in 1987/88. The combination of 0·6 ID:CPE with 60 kg N/ha gave a significantly higher seed yield than lower rates and equalled that from the highest irrigation and N treatment combinations. The amount of water used by the mustard crop decreased with increasing soil depth irrespective of treatment. In the deeper soil layers, the percentage of total moisture use was greater under less irrigated than under more frequently irrigated plots. Leaf area index showed a significant positive linear relationship with evapotranspiration and light absorption and a negative linear relationship with canopy temperature. Seed yield was linearly related to leaf area index and light absorption coefficient.

scholarly journals Monitoring leaf area index at watershed level through NDVI from Landsat-7/ETM+ data

2004 ◽  
Vol 61 (3) ◽  
pp. 243-252 ◽  
Author(s):  
Alexandre Cândido Xavier ◽  
Carlos Alberto Vettorazzi
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Vegetation Index ◽  
Hydrological Cycle ◽  
Riparian Forest ◽  
Empirical Relationships ◽  
Area Index ◽  
Landsat 7 ◽  
The Mean ◽  
The Relationship

Leaf area index (LAI) is an important parameter of the vegetation canopy, and is used, for instance, to estimate evapotranspiration, an important component of the hydrological cycle. This work analyzed the relationship between LAI, measured in field, and NDVI from four dates (derived from Landsat-7/ETM+ data), and with such vegetation index, to generate and analyze LAI maps of the study area for the diverse dates. LAI data were collected monthly in the field with LAI-2000 equipment in stands of sugar cane, pasture, corn, eucalypt, and riparian forest. The relationships between LAI and NDVI were adjusted by a potential model; 57% to 72% of the NDVI variance were explained by the LAI. LAI maps generated by empirical relationships between LAI and NDVI showed reasonable precision (standard error of LAI estimate ranged from 0.42 to 0.87 m² m-2). The mean LAI value of each monthly LAI map was shown to be related to the total precipitation in the three previous months.

Relationship of thematic mapper simulator data to leaf area index of temperate coniferous forests

1987 ◽  
Vol 22 (3) ◽  
pp. 323-341 ◽  
Author(s):  
David L. Peterson ◽  
Michael A. Spanner ◽  
Steven W. Running ◽  
Kurt B. Teuber
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Thematic Mapper ◽  
Coniferous Forests ◽  
Area Index ◽  
Relationship Of
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