scholarly journals Physiological and Morphological Features Determining the Performance of the Sorghum Landraces of Northern Nigeria

1996 ◽  
Vol 32 (2) ◽  
pp. 129-141 ◽  
Author(s):  
D. J. Flower
Keyword(s):  
Dry Matter ◽  
Morphological Features ◽  
Light Extinction ◽  
Light Use Efficiency ◽  
Northern Nigeria ◽  
Low Light ◽  
Light Extinction Coefficient ◽  
Matter Production ◽  
Early Maturing ◽  
Use Efficiency

SUMMARYSorghum landraces from contrasting districts of northern Nigeria were grown during the 1990 rainy season to describe their physiological and morphological features. Changes in their dry matter production and yield could be predicted from thermal time to flowering (based on response to a fixed daylength) and partitioning indices. Many other morphological and physiological features, such as light-extinction coefficient, light-use efficiency, plant height, leaf area and leaf number, were either stable or varied systematically with time to flowering. Grain yields of early maturing lines were limited by low light interception from flowering to physiological maturity and those of later maturing lines by highly site-specific drought stress.

scholarly journals The effect of timing of shade on development, dry matter production and light-use efficiency in groundnut (Arachis hypogaea L.) under field conditions

1990 ◽  
Vol 41 (4) ◽  
pp. 633 ◽  
Author(s):  
CM Stirling ◽  
JH Williams ◽  
CR Black ◽  
CK Ong
Keyword(s):  
Arachis Hypogaea ◽  
Dry Matter ◽  
Incident Light ◽  
Light Use Efficiency ◽  
Matter Production ◽  
Arachis Hypogaea L ◽  
Leaf Area Expansion ◽  
Use Efficiency ◽  
Area Expansion ◽  
Final Harvest

During the rainy season in India, bamboo screens intercepting approximately 46% of the incident light were used to simulate the effect of shading by a cereal grown as an intercrop with groundnut (Arachis hypogaea L.). The treatments comprised an unshaded control and two durations of shading extending from peg initiation (T1) and the onset of pod filling (T2) to final harvest. Plant height was greatest in the T1 crop, but the maximum rates of leaf development on the main stem, leaf area expansion and pod production were similar in all crops. Shading appeared to reduce the rate of the linear growth phase because the reduced light interception was not entirely offset by an increase in light-use efficiency. Premature senescence in the shaded crops coincided with the virtual cessation of pod production, although continued allocation of dry matter to reproductive structures in the T1 crop resulted in a greater proportion of pods being filled at final harvest than in the other treatments. The responses of groundnut to timing of shade are discussed in terms of their implications for the selection of improved crop combinations for intercropping.

Nitrogen-limited light use efficiency in wheat crop simulators: comparing three model approaches

2015 ◽  
Vol 154 (6) ◽  
pp. 1090-1101 ◽  
Author(s):  
A. M. RATJEN ◽  
H. KAGE
Keyword(s):  
Dry Matter ◽  
Dry Matter Production ◽  
Wheat Crop ◽  
Light Use Efficiency ◽  
Data Set ◽  
Area Index ◽  
N Concentration ◽  
Matter Production ◽  
Use Efficiency ◽  
Critical N Concentration

SUMMARYThree different explanatory indicators for reduced light use efficiency (LUE) under limited nitrogen (N) supply were evaluated. The indicators can be used to adapt dry matter production of crop simulators to N-limited growth conditions. The first indicator, nitrogen factor (NFAC), originates from the CERES-Wheat model and calculates the critical N concentration of the shoot as a function of phenological development. The second indicator, N nutrition index (NNI), calculates a critical N concentration as a function of shoot dry matter. The third indicator, specific leaf nitrogen (SLN) index (SLNI), has been newly developed. It compares the actual SLN with the maximum SLN (SLNmax). The latter is calculated as a function of the green area index (GAI). The comparison was based on growth curves and fitted to empirical data, and was carried out independently from a dynamic crop model. The data set included four growing seasons (2004–2006, 2012) in Northern Germany and seven modern bread wheat cultivars with varying N fertilization levels (0–320 kg N/ha). The influence of N shortage on LUE was evaluated from the beginning of stem elongation until flowering. With the exception of 2005, the highest productivity was observed for the highest N level. A moderate N shortage primarily reduced GAI and therefore light interception, while LUE remained stable under moderate N shortage. The relative LUE (rLUE) of a specific day was defined as the ratio of actual to maximal LUE. None of the indicators was proportional to rLUE, but the relationships were described well by quadratic plateau curves. The correlation between simulated and measured rLUE was significant for all explanatory indicators, but different in terms of mean absolute error and coefficient of determination (R2). The performance of SLNI and NNI was similar, but the goodness of prediction was much lower for NFAC. Compared with NNI and NFAC, SLNI corresponded to leaf N and was therefore sensitive to N translocation from leaves to growing grains during the reproductive stage. For this reason, SLNI may have the potential to improve simulation of dry matter production in wheat crop simulators.

scholarly journals Physiological and Morphological Changes Over the Past 50 Years in Yield Components in Tomato

2009 ◽  
Vol 134 (4) ◽  
pp. 460-465 ◽  
Author(s):  
Tadahisa Higashide ◽  
Ep Heuvelink
Keyword(s):  
Dry Matter ◽  
Matter Content ◽  
Fruit Yield ◽  
Light Extinction ◽  
Dry Matter Content ◽  
Light Extinction Coefficient ◽  
The Past ◽  
Matter Production ◽  
Leaf Photosynthetic Rate ◽  
Japanese Cultivar

Greenhouse tomato (Solanum lycopersicum) yield in The Netherlands has increased tremendously over the past 50 years. The effects of breeding during this period were investigated. Eight Dutch cultivars and one typical current Japanese cultivar that were released over the past 50 years were compared in a short-term experiment conducted from summer to fall in The Netherlands. Fresh fruit yield of the Dutch cultivars significantly increased ≈0.9% per year with the year of release from 1950 to 2000. Dry weight fruit yield of the Dutch cultivars also increased with the year of release, whereas the fruit dry matter content was not correlated with the year of release. Total dry matter production of plants increased with the year of release, and the dry matter partitioning to fruit was not correlated with the year of release. An increase in dry matter production was caused not by an increase in fraction of intercepted light, but by light use efficiency based on correlations between each of them and the year of release. The light extinction coefficient in the plant canopy decreased, whereas leaf photosynthetic rate increased significantly with the year of release. Although fresh fruit yield of the Japanese cultivar was lower than that of the modern Dutch cultivars, fruit dry matter content of the Japanese cultivar was higher than that of the Dutch cultivars. An increase in yield over the past 50 years in Dutch tomato was caused by an increase in light use efficiency resulting from a decrease in light extinction coefficient (a morphological change) and an increase in leaf photosynthetic rate (a physiological change).

Light-use efficiency of native and hybrid poplar genotypes at high levels of intracanopy competition

2001 ◽  
Vol 31 (6) ◽  
pp. 1030-1037 ◽  
Author(s):  
D Scott Green ◽  
Eric L Kruger ◽  
Glen R Stanosz ◽  
J G Isebrands
Keyword(s):  
Populus Deltoides ◽  
Hybrid Poplar ◽  
Light Extinction ◽  
Light Use Efficiency ◽  
Light Extinction Coefficient ◽  
Cultural Conditions ◽  
Compensation Irradiance ◽  
Use Efficiency ◽  
Additive Combination ◽  
Growing Conditions

In southern Wisconsin, U.S.A., tree growth and associated canopy traits were compared among five native and hybrid genotypes of poplar (Populus spp.) in replicated, monoclonal stands planted at a 1 × 1 m spacing. The overall objective of this study was to assess clonal suitability to cultural conditions entailing high levels of intracanopy competition (such as high-density plantations or long rotations) and to identify selection criteria suitable to such conditions. Two of the clones were Populus deltoides Bartr., two were P. deltoides × Populus nigra L. (DN) crosses, and the fifth was a P. nigra × Populus maximowiczii A. Henry (NM) cross. In the third year after establishment, variation in aboveground biomass gain (ANBG) was analyzed in relation to canopy light interception (IPAR) and canopy light-use efficiency (LUE) during a 31-day period when growing conditions were most favorable (late June through late July). ANBG in this interval varied by twofold among genotypes (2.76–5.78 Mg·ha–1), and it was highest in the two P. deltoides clones, followed by the NM and DN hybrids, respectively. Across genotypes, ANBG was unrelated to IPAR, which varied by only 5%. Instead, it was strongly and positively related (r2 = 0.99) to the twofold variation in LUE (1.06–2.22 g·MJ–1). Among measured canopy traits, the best predictor of LUE (r2 = 0.88) was an additive combination of factors associated to the optimization of canopy photosynthesis: LUE was negatively related to both the canopy light-extinction coefficient and compensation irradiance at the canopy base. We infer from these findings that poplar genotypes can vary considerably in LUE and, correspondingly, in the extent to which photosynthesis is optimized in dense canopies. Furthermore, the low LUE among hybrid genotypes at this level of intracanopy competition may reflect a bias in "tree improvement" efforts towards maximizing biomass production under conditions of relatively low competition.

Discrimination in Carbon Isotopes of Leaves Correlates With Water-Use Efficiency of Field-Grown Peanut Cultivars

1988 ◽  
Vol 15 (6) ◽  
pp. 815 ◽  
Author(s):  
GC Wright ◽  
KT Hubick ◽  
GD Farquhar
Keyword(s):  
Water Use Efficiency ◽  
Water Use ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Dry Matter Yield ◽  
Strong Negative Correlation ◽  
Matter Production ◽  
Whole Plant ◽  
Use Efficiency ◽  
The Relationship

Variation in water-use efficiency (W, g of total dry matter produced/kg water used), and its correlation with cultivar isotope discrimination in leaves (Δ) was assessed in peanut plants grown in small canopies in the field. Plants were grown in separate minilysimeters that were both embedded in the ground and positioned above the crop. Differences among cultivars were found in W and � and the relationship between W and Δ was compared for plants grown in open and closed canopies. Genetic variability in W in plants grown in the field under non-limiting water conditions was demonstrated, with Tifton-8, of Virginia habit, having the highest W (3.71 g/kg) and Rangkasbitung, an Indonesian cultivar of Spanish habit, the lowest (2.46 g/ kg). Variability in W was due to variation in total dry matter production more than that of water use. A strong negative correlation was found between Δ and W, and also between Δ and total dry matter. The relationship between whole plant W, including roots, and Δ was stronger than that between shoot W, without roots and Δ. The improvement occurred because of variation among cultivars in the root to shoot ratio. This highlights the importance of taking account of root dry matter in studies concerning W. There were significant differences in W and Δ between plants in pots above-ground compared to pots in the ground, with above-ground plants having significantly lower values of both W and Δ. The ranking of W and Δ among cultivars was not affected by the contrast in environment, which suggests these parameters are under strong genetic control. Total above-ground dry matter yield at maturity was negatively correlated with Δ, while pod yield was not. It appears a negative association between harvest index and Δ may exist; however not all cultivars used in this and other studies follow this response. Both water-use efficiency, Wand total dry matter production are negatively correlated with Δ in leaves of peanut plants grown in small canopies in the field. Measurement of Δ may prove a useful trait for selecting cultivars with improved W and total dry matter yield under field conditions.

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