Maize radiation use-efficiency response to optimally distributed foliar-nitrogen-content depends on canopy leaf-area index

2020 ◽  
Vol 247 ◽  
pp. 107557 ◽  
Author(s):  
Lucas E. Bonelli ◽  
Fernando H. Andrade
2015 ◽  
Vol 154 (4) ◽  
pp. 662-673 ◽  
Author(s):  
D. C. CAMARGO ◽  
F. MONTOYA ◽  
M. A. MORENO ◽  
J. F. ORTEGA ◽  
J. I. CÓRCOLES

SUMMARYThe aim of the current research was to analyse the effect of four water irrigation treatments (1·20, 1·00, 0·80 and 0·60 of the crop water requirement) on the relationships among leaf area index (LAI), radiation use efficiency (RUE) and green canopy cover in a potato crop (Solanum tuberosumL.) cv. Agria. The crop was established in a commercial plot irrigated with a centre pivot system in Southeast Spain during the 2011 and 2012 seasons. In both seasons, the highest light absorption efficiency values occurred at the LAI value of 3 that corresponded to maximum ground cover. With regard to the irrigation treatment, a significant linear response was indicated for RUE. The results indicate that the 1·00 irrigation treatment produced the best result, improving water resources management without reducing crop yield.


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.


2021 ◽  
Vol 22 (3) ◽  
pp. 285-294
Author(s):  
KOUSHIK BAG ◽  
K.K. BANDYOPADHYAY ◽  
V.K. SEHGAL ◽  
A. SARANGI ◽  
P. KRISHNAN

In this study, we have evaluated the effect of different tillage (conventional tillage (CT) and no tillage (NT)), residue (with crop residue mulch (R+) and without residue (R0)) and nitrogen (60, 120 and 180 kgN ha-1) interaction for radiation interception, radiation use efficiency (RUE), evapotranspiration (ET) partitioning and yield of wheat in a split-split plot design for 2017-18 and 2018-19. Results showed that Leaf Area Index (LAI), Leaf area duration (LAD), Total intercepted photosynthetically active radiation (TIPAR), Grain and Biomass yields were higher in R+ during both the years of study. With increasing Ndoses LAI, LAD, TIPAR, RUE, grain and biomass yields increased and extinction coefficient decreased significantly in both the years. Fraction intercepted photosynthetically active radiation (fIPAR) followed a similar trend with LAI. Seasonal ET was partitioned into soil evaporation (Ep) and crop transpiration (Tp) to take into account the productive transpiration effects on crop growth and yield. It was found that NT and residue could reduce Ep (6% and 5.6%) and increased Tp (2.6% and 2.4%) over CT and no mulch treatments, respectively. With higher N-dose, Ep decreased while Tp increased significantly. Thus besides higher nitrogen doses, NT and crop residue mulching could be a better strategy to harness higher radiation interception vis-a-vis higher crop productivity.


2021 ◽  
Vol 74 (3) ◽  
pp. 9621-9629
Author(s):  
Jamer Alexis Ramirez Jimenez ◽  
Paulo Eduardo Ribeiro Marchiori ◽  
Oscar de Jesús Córdoba-Gaona

Grafting is an effective approach to improve tomato yield and for tolerance to various abiotic and biotic stresses. This technique consists of using a vigorous or resistant plant (rootstock) to replace the root system of a genotype of economic interest (scion) but susceptible to one or more stress factors. The present work aimed to evaluate the physiological and productive response of a commercial tomato scion grafted on different rootstocks in Colombia’s high-Andean region. For this purpose, a tomato cv. Libertador was grafted on two commercial (“Olimpo” and “Armada”) tomato rootstocks in a randomized complete block experimental design. Four scion×rootstock combinations were evaluated by vigor rootstock, resistant rootstock, self-grafting, and non-grafted plants. Net photosynthesis, transpiration rate, stomatal conductance, water use efficiency, and radiation use efficiency were evaluated during six phenological stages (701, 704, 706, 708, 710, and 712), according to the BBCH scale; while the leaf area index and quantum yield were analyzed in five phenological stages (except 706). The highest values of photosynthesis, stomatal conductance, water and radiation use efficiency were registered in the initial phase of the production stage (701), which tended to decline at the end of the life cycle (712). Transpiration rate was similar throughout the growth cycle. Nevertheless, vigor rootstock presented the lowest photosynthesis rate; it was superior in terms of leaf area index, leaves dry matter, and tomato yield. The quantum yield values of the photosystem II did not indicate photochemical injuries in any of the scion×rootstock combinations. The higher tomato yield was reached in vigor rootstock and was associated with a more significant accumulation of dry matter in the leaf and higher leaf area index.


2007 ◽  
Vol 4 (4) ◽  
pp. 647-656 ◽  
Author(s):  
M. Jung ◽  
G. Le Maire ◽  
S. Zaehle ◽  
S. Luyssaert ◽  
M. Vetter ◽  
...  

Abstract. Three terrestrial biosphere models (LPJ, Orchidee, Biome-BGC) were evaluated with respect to their ability to simulate large-scale climate related trends in gross primary production (GPP) across European forests. Simulated GPP and leaf area index (LAI) were compared with GPP estimates based on flux separated eddy covariance measurements of net ecosystem exchange and LAI measurements along a temperature gradient ranging from the boreal to the Mediterranean region. The three models capture qualitatively the pattern suggested by the site data: an increase in GPP from boreal to temperate and a subsequent decline from temperate to Mediterranean climates. The models consistently predict higher GPP for boreal and lower GPP for Mediterranean forests. Based on a decomposition of GPP into absorbed photosynthetic active radiation (APAR) and radiation use efficiency (RUE), the overestimation of GPP for the boreal coniferous forests appears to be primarily related to too high simulated LAI - and thus light absorption (APAR) – rather than too high radiation use efficiency. We cannot attribute the tendency of the models to underestimate GPP in the water limited region to model structural deficiencies with confidence. A likely dry bias of the input meteorological data in southern Europe may create this pattern. On average, the models compare similarly well to the site GPP data (RMSE of ~30% or 420 gC/m2/yr) but differences are apparent for different ecosystem types. In terms of absolute values, we find the agreement between site based GPP estimates and simulations acceptable when we consider uncertainties about the accuracy in model drivers, a potential representation bias of the eddy covariance sites, and uncertainties related to the method of deriving GPP from eddy covariance measurements data. Continental to global data-model comparison studies should be fostered in the future since they are necessary to identify consistent model bias along environmental gradients.


2011 ◽  
Vol 62 (10) ◽  
pp. 840 ◽  
Author(s):  
E. Chakwizira ◽  
D. J. Moot ◽  
W. R. Scott ◽  
A. L. Fletcher ◽  
S. Maley

Inadequate phosphorus (P) supply at crop establishment can reduce dry matter (DM) accumulation. A field experiment quantified the effects of banded or broadcast P fertiliser (0, 20, 40 or 60 kg P/ha) applied at establishment to moderately fertile soils on growth and development of ‘Regal’ kale (Brassica oleracea var. acephala L.) crops. DM yield increased from 8710 to ~11 400 kg/ha by the addition of P fertiliser but was unaffected by the method of P application. The control crops accumulated 630 kg DM/100 degree-day (degree-day-accumulated heat available for crop growth) compared with ~800 kg/100 degree-day for the P-fertilised crops. The yield response to P was caused by an increased rate of development of leaf area index (LAI) and consequently earlier canopy closure that led to higher accumulated radiation interception (RIcum). The maximum LAI for the control crops was 3.80 or 24% lower than for fertilised crops. At the final harvest total RIcum for P-fertilised crops was 22% higher than the 592 MJ/m2 for the control, and this accounted for 80% of their yield differences. Leaf appearance rates were unaffected by P supply, with a common phyllochron of 109 degree-day. There was a consistent relationship between light interception and LAI, with a critical LAI of 3.40, extinction coefficient of 0.90 and radiation-use efficiency of 1.56 g/MJ photosynthetically active radiation. Overall, these results support a starter P application of at least 20 kg P/ha at establishment to maximise yields for kale crops when initial soil Olsen P levels ranged from 9 to 17 mg/kg soil.


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