scholarly journals First vs. second rotation of a poplar short rotation coppice: leaf area development, light interception and radiation use efficiency

2015 ◽  
Vol 8 (5) ◽  
pp. 565-573 ◽  
Author(s):  
LS Broeckx ◽  
SP Vanbeveren ◽  
MS Verlinden ◽  
R Ceulemans
Weed Science ◽  
1999 ◽  
Vol 47 (3) ◽  
pp. 291-296 ◽  
Author(s):  
Stevan Z. Knezevic ◽  
Michael J. Horak ◽  
Richard L. Vanderlip

Redroot pigweed is a troublesome weed in the sorghum-growing regions of North America. In 1994 and 1995, field studies were conducted at two locations near Manhattan, KS, to determine the influence of redroot pigweed density and environmental conditions on physiological determinants of redroot pigweed growth: duration of plant growth, light interception, radiation-use efficiency, and dry matter partitioning. In addition, specific leaf area was determined. Redroot pigweed was seeded at monoculture densities of 2, 4, and 12 plants m−1of row each year at each location. Duration of redroot pigweed growth was not influenced by plant density. Light interception was defined as a simple exponential function of leaf area index. Specific leaf area did not change over the season and averaged 135 cm2g−1. Partitioning of redroot pigweed dry matter was not influenced by plant density or environmental conditions but did not change within vegetative and reproductive stages. Radiation-use efficiency was not influenced by redroot pigweed density; the most reliable estimate was 1.74 g dry matter MJ−1of intercepted photosynthetically active radiation. Physiological determinants described were not affected by redroot pigweed density or environmental conditions and therefore provide a starting point for the development of a redroot pigweed growth module. The module could be coupled with available crop growth models (e.g., the sorghum growth model SORKAM) to simulate redroot pigweed–sorghum competition.


Crop Science ◽  
1998 ◽  
Vol 38 (3) ◽  
pp. 827-834 ◽  
Author(s):  
I. C. Madakadze ◽  
B. E. Coulman ◽  
P. Peterson ◽  
K. A. Stewart ◽  
R. Samson ◽  
...  

Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 101-110 ◽  
Author(s):  
S. Sridhara ◽  
T.G. Prasad

SUMMARYA field experiment was conducted at Gandhi Krishi Vignana Kendra, University of Agricultural Sciences, Bangalore to study the effect of irrigation regimens on the biomass accumulation, canopy development, light interception and radiation use efficiency of sunflower. The treatments includes irrigating the plants at 0.4, 0.6, 0.8 and 1.0 cumulative pan evaporation. The results indicated that the aboveground biomass, canopy development, radiation interception and radiation use efficiency were influenced favorably by the irrigation regimens. Irrespective of the irrigation regimen, the radiation use efficiency of sunflower increased from 15 DAS to 75 DAS and then tended to decline. The decrease in RUE after anthesis is coupled with decrease in leaf nitrogen content. In general the RUE of sunflower ranged from 0.49 g MJ-1 to 1.84 g MJ-1 at different growth stages. The light transmission within the canopy increased exponentially with plant height and the canopy extension coefficient is found to be 0.8.


2016 ◽  
Vol 53 (2) ◽  
pp. 210-225 ◽  
Author(s):  
GUILHERME M. TORRES ◽  
ADRIAN KOLLER ◽  
RANDY TAYLOR ◽  
WILLIAM R. RAUN

SUMMARYSeed-oriented planting provides a manner to influence canopy structure. The purpose of this research was to improve maize light interception using seed-oriented planting to manipulate leaf azimuth across the row thereby minimizing leaf overlap. To achieve leaf azimuths oriented preferentially across the row, seeds were planted: (i) upright with caryopsis pointed down, parallel to the row (upright); and (ii) laying flat, embryo up, perpendicular to the row (flat). These treatments were compared to conventionally planted seeds with resulting random leaf azimuth distribution. Seed orientation effects were contrasted with three levels of plant population and two levels of hybrid specific canopy structures. Increased plant population resulted in greater light interception but yield tended to decrease as plant population increased. The planophile hybrid produced consistently greater yields than the erectophile hybrid. The difference between planophile and erectophile hybrids ranged from 283 to 903 kg ha−1. Overall, mean grain yield for upright and flat seed placement increased by 351 and 463 kg ha−1 compared to random seed placement. Greater cumulative intercepted photosynthetically active radiation (CIPAR) was found for oriented seeds rather than random-oriented seeds. At physiological maturity upright, flat and random-oriented seeds intercepted 555, 525 and 521 MJ m−2 of PAR, respectively. Maize yield responded positively to improved light interception and better radiation use efficiency. Under irrigated conditions, precision planting of maize increased yield by 9 to 14% compared to random-oriented seeds.


2008 ◽  
Vol 35 (10) ◽  
pp. 885 ◽  
Author(s):  
Gaëtan Louarn ◽  
Karine Chenu ◽  
Christian Fournier ◽  
Bruno Andrieu ◽  
Catherine Giauffret

Maize (Zea mays L.) is a chill-susceptible crop cultivated in northern latitude environments. The detrimental effects of cold on growth and photosynthetic activity have long been established. However, a general overview of how important these processes are with respect to the reduction of productivity reported in the field is still lacking. In this study, a model-assisted approach was used to dissect variations in productivity under suboptimal temperatures and quantify the relative contributions of light interception (PARc) and radiation use efficiency (RUE) from emergence to flowering. A combination of architectural and light transfer models was used to calculate light interception in three field experiments with two cold-tolerant lines and at two sowing dates. Model assessment confirmed that the approach was suitable to infer light interception. Biomass production was strongly affected by early sowings. RUE was identified as the main cause of biomass reduction during cold events. Furthermore, PARc explained most of the variability observed at flowering, its relative contributions being more or less important according to the climate experienced. Cold temperatures resulted in lower PARc, mainly because final leaf length and width were significantly reduced for all leaves emerging after the first cold occurrence. These results confirm that virtual plants can be useful as fine phenotyping tools. A scheme of action of cold on leaf expansion, light interception and radiation use efficiency is discussed with a view towards helping breeders define relevant selection criteria.


2009 ◽  
Vol 44 (10) ◽  
pp. 1211-1218 ◽  
Author(s):  
Paulo Jorge de Oliveira Ponte de Souza ◽  
Aristides Ribeiro ◽  
Edson José Paulino da Rocha ◽  
José Renato Bouça Farias ◽  
Renata Silva Loureiro ◽  
...  

The objective of this work was to evaluate the efficiency of soybean (Glycine max) in intercepting and using solar radiation under natural field conditions, in the Amazon region, Brazil. The meteorological data and the values of soybean growth and leaf area were obtained from an agrometeorological experiment carried out in Paragominas, Pará state, during 2007 and 2008. The radiation use efficiency (RUE) was obtained from the ratio between the above-ground biomass production and the intercepted photosynthetically active radiation (PAR) accumulated to 99 and 95 days after sowing, in 2007 and 2008, respectively. Climatic conditions during the experiment were very distinct, with reduction in rainfall in 2007, which began during the soybean mid-cycle, due to the El Niño phenomenon. An important reduction in the leaf area index and biomass production was observed during 2007. Under natural field conditions in the Amazon region, the values of RUE were 1.46 and 1.99 g MJ-1 PAR in the 2007 and 2008 experiments, respectively. The probable reason for the differences found between these years might be associated to the water restriction in 2007 coupled with the higher air temperature and vapor pressure deficit, and also to the increase in the fraction of diffuse radiation that reached the land surface in 2008.


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