scholarly journals Leaf angle distribution in Johnsongrass, leaf thickness in sorghum and Johnsongrass, and association with response to Colletotrichum sublineola

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ezekiel Ahn ◽  
Gary Odvody ◽  
Louis K. Prom ◽  
Clint Magill

AbstractBasal leaf angle distribution was surveyed in twenty-one Johnsongrass cultivars near the end of the vegetative stage. The angles increased from the top to the bottom leaves, and compared to cultivated grain sorghums, the average angle was larger in Johnsongrass. When basal leaf angle distribution data were correlated with pathogenicity test data from excised-leaf assays for three isolates of Colletotrichum sublineola, the results showed a weak positive correlation between basal leaf angle and pathogenicity level in Johnsongrass. In order to investigate a protective role of leaf thickness to C. sublineola, leaf thickness was measured in three sorghum cultivars and one Johnsongrass cultivar at the 8-leaf-stage. Leaf thickness near the apex, near the base, and half-way between the two points were measured in the top four leaves of each plant. Thickness of leaf blade and midrib were recorded separately. Using an excised-leaf-assay, the three points were inoculated with C. sublineola, and pathogenicity level was recorded 4-days-post-inoculation. Results showed strong negative correlations between leaf midrib thickness and pathogenicity level in sorghum and Johnsongrass but not in leaf blades.

Author(s):  
I. V. Matelenok ◽  
◽  
F. A. Alekseev ◽  
E. A. Evdokimova ◽  
◽  
...  

Methods for retrieving leaf inclination angles in a forest canopy are considered. To acquire data on the orientation of Sorbus aucuparia leaves, a technique based on leveled camera digital photography well suited for conducting surveys in a boreal forest was used. In the course of field and office work, leaf angle distribution data for the specified species in the Priozersky district of the Leningrad region was obtained and analyzed. Values of the Ross-Nielson integral function were estimated.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ezekiel Ahn ◽  
Gary Odvody ◽  
Louis K. Prom ◽  
Clint Magill

An amendment to this paper has been published and can be accessed via a link at the top of the paper.


Plant Methods ◽  
2015 ◽  
Vol 11 (1) ◽  
pp. 11 ◽  
Author(s):  
Mark Müller-Linow ◽  
Francisco Pinto-Espinosa ◽  
Hanno Scharr ◽  
Uwe Rascher

2019 ◽  
Vol 16 (8) ◽  
pp. 1190-1194 ◽  
Author(s):  
Jianbo Qi ◽  
Donghui Xie ◽  
Linyuan Li ◽  
Wuming Zhang ◽  
Xihan Mu ◽  
...  

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 686 ◽  
Author(s):  
Xuhan Wu ◽  
Weiliang Fan ◽  
Huaqiang Du ◽  
Hongli Ge ◽  
Feilong Huang ◽  
...  

Both leaf area (LA) and leaf angle distribution are the most important eco-physiological measures of tree crowns. However, there are limited published investigations on the two parameters of Moso bamboo (Phyllostachys edulis (Carrière) J. Houz., abbreviated as MB). The aim of this study was to develop allometric equations for predicting crown LA of MB by taking the diameter at breast height (DBH) and tree height (H) as predictors and to investigate the leaf angle distribution of a MB crown based on direct leaf angle measurements. Data were destructively sampled from 29 MB crowns including DBH, H, biomass and the area of sampled leaves, biomass of total crown leaves, and leaf angles. The results indicate that (1) the specific leaf area (SLA) of a MB crown decreases from the bottom to the top; (2) the vertical LA distribution of MB crowns follow a “Muffin top” shape; (3) the LA of MB crowns show large variations, from 7.42 to 74.38 m2; (4) both DBH and H are good predictors in allometry-based LA estimations for a MB crown; (5) linear, exponential, and logarithmic regressions show similar capabilities for the LA estimations; (6) leaf angle distributions from the top to the bottom of a MB crown can be considered as invariant; and (7) the leaf angle distribution of a MB crown is close to the planophile case. The results provide an important tool to estimate the LA of MB on the standing scale based on DBH or H measurements, provide useful prior knowledge for extracting leaf area indexes of MB canopies from remote sensing-based observations, and, therefore, will potentially serve as a crucial reference for calculating carbon balances and other ecological studies of MB forests.


2019 ◽  
Vol 148 ◽  
pp. 208-220 ◽  
Author(s):  
Jing Liu ◽  
Andrew K. Skidmore ◽  
Tiejun Wang ◽  
Xi Zhu ◽  
Joe Premier ◽  
...  

2017 ◽  
Vol 35 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Carlos Andrés Unigarro M. ◽  
Álvaro Jaramillo R. ◽  
Claudia Patricia Flórez R.

The study was conducted at the "Estación Central Naranjal Ce-nicafé" (National Coffee Research Center, Chinchina, Caldas, Colombia) on Coffea arábica L. variety Castillo® to find the leaf angle distribution function that best described the tilt of the angles present in the canopy. Leaf angles were recorded for 1,559 leaves located in the upper, middle and lower profiles of the canopy. The observed leaf angle distribution was compared with the Beta, ellipsoidal and four de Wit distribution functions. The fit between comparisons was determined by the Pearson X2 test and its significance, the regression coefficient statistically equal to one and the RMSE. Likewise, the leaf angle distribution recorded in the field per profile and their combination was described based on three angle classes (1stclass: 0°-30°; 2nd class: 30°-60°; and 3rd class: 60°-90°) according to the Goudriaan criterion. Generally, the leaf angle distribution present in the canopy of Castillo® coffee variety is adequately described by the Beta function with two parameters and the ellipsoidal function based on the adjustment provided by the statistical tests.


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