scholarly journals Influence of water deficit on transpiration and radiation use efficiency of chickpea (Cicer arietinum L.)

1989 ◽  
Vol 48 (3-4) ◽  
pp. 317-330 ◽  
Author(s):  
Piara Singh ◽  
Y.V Sri Rama
2018 ◽  
Vol 33 (4) ◽  
pp. 579-587
Author(s):  
Denis de Pinho Sousa ◽  
Paulo Jorge Oliveira Ponte de Souza ◽  
Vivian Dielly da Silva Farias ◽  
Hildo Giuseppe Caldas Nunes ◽  
Denílson Pontes Ferreira ◽  
...  

Abstract This study aims to determine the cowpea efficiency in absorbing and using solar radiation according to different irrigation depths under the climatic conditions of the northeast of Pará State. The experiment was carried out on 2014 and 2016 in an experimental design of randomized blocks, which consisted in six blocks with four treatments, in which different irrigation depths the reproductive phase were applied, as follows: T100, T50, T25 e T0, that corresponded to 100%, 50%, 25% e 0% of the crop evapotranspiration, respectively. The absorbed photosynthetically active radiation, leaf area index (LAI), total aerial dry matter (TADM) and grain yield were measured. The extinction coefficient (k) was obtained by nonlinear regression between the fraction of absorbed PAR (fPARinter) and the LAI. The radiation use efficiency (RUE) was calculated by linear regression between the TADM and the accumulated absorbed PAR. The water deficit imposed by the treatments had a significant influence on the LAI, TADM and cowpea yields. The water deficit did not significantly influenced k – it ranged between 0.83 for T100 and 0.70 for T0. The RUE showed significant behaviors regarding the treatments with adequate water supply and treatments under water deficit, ranging from 2.23 to 1.64 g·MJ-1, respectively.


2001 ◽  
Vol 52 (1) ◽  
pp. 103 ◽  
Author(s):  
P. J. Stone ◽  
D. R. Wilson ◽  
J. B. Reid ◽  
R. N. Gillespie

The responses of sweet corn biomass and yield to timing and severity of water deficit were determined in an experiment using a mobile rainshelter. Six irrigation treatments were applied such that plots experienced: (1) no water deficit; (2) full water deficit; (3) moderate pre-silking deficit; (4) severe pre-silking deficit; (5) moderate post-silking deficit; or (6) severe post-silking deficit. Drought was quantified using the concept of potential soil moisture deficit, which was calculated from climatic data. Potential soil moisture deficit can be related simply to a wide range of plant performance variables, making it possible to compare the relative importance of variables in determining the overall response of the crop to drought. For all treatments, yield was related strongly to biomass, especially that accumulated after silking. Biomass, in turn, was reduced by water deficit, mainly because of reduced radiation use efficiency, but also because of reduced total radiation interception, particularly in early deficit treatments. Both water use efficiency and transpiration efficiency increased with water deficit, even though soil evaporation as a proportion of total water use also increased with deficit. There was no stage of crop development at which yield was particularly sensitive to water deficit, although yield components changed with timing of deficit. Importantly, measures of potential soil moisture deficit integrated the effects of timing and severity of drought, making it possible to simply and mechanistically account for the effects of water deficit on biomass and particularly yield.


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.


Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 351
Author(s):  
Adolfo Rosati ◽  
Damiano Marchionni ◽  
Dario Mantovani ◽  
Luigi Ponti ◽  
Franco Famiani

We quantified the photosynthetically active radiation (PAR) interception in a high-density (HD) and a super high-density (SHD) or hedgerow olive system, by measuring the PAR transmitted under the canopy along transects at increasing distance from the tree rows. Transmitted PAR was measured every minute, then cumulated over the day and the season. The frequencies of the different PAR levels occurring during the day were calculated. SHD intercepted significantly but slightly less overall PAR than HD (0.57 ± 0.002 vs. 0.62 ± 0.03 of the PAR incident above the canopy) but had a much greater spatial variability of transmitted PAR (0.21 under the tree row, up to 0.59 in the alley center), compared to HD (range: 0.34–0.43). This corresponded to greater variability in the frequencies of daily PAR values, with the more shaded positions receiving greater frequencies of low PAR values. The much lower PAR level under the tree row in SHD, compared to any position in HD, implies greater self-shading in lower-canopy layers, despite similar overall interception. Therefore, knowing overall PAR interception does not allow an understanding of differences in PAR distribution on the ground and within the canopy and their possible effects on canopy radiation use efficiency (RUE) and performance, between different architectural systems.


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