scholarly journals Breeding strategies for soybean canopy structure optimization in dry regions

2021 ◽  
Vol 186 (2) ◽  
pp. 24-30
Author(s):  
V.E. Rosenzweig ◽  
◽  
D.V. Goloenko ◽  
Keyword(s):  
Leaf Area ◽  
Leaf Surface ◽  
Effective Means ◽  
Canopy Structure ◽  
Leaf Size ◽  
Leaf Number ◽  
Width Ratio ◽  
Area Index ◽  
Trifoliate Leaf ◽  
Soybean Canopy

Water supply is one of the key factors limiting soybean yield. Coming from the monsoon climate region, soybean lacks effective means of leaf surface growth restriction and is prone to produce excessive leaf area that leads to undesirable transpiration increase. Reducing branching rate and, correspondingly, leaf number per plant is usually proposed to decrease leaf area. However, as far as branching ability is generally a useful trait contributing to yield stability, we have undertaken a search for possible alternative ways of leaf area reduction. Soybean canopy structure was studied in our germplasm nursery in Kursk region. We have updated an express method of soybean trifoliate leaf surface calculation. A regression index for soybean trifoliate leaf surface by central leaflet length and width product characterizes leaflet shape and depends from its length to width ratio. In the sampling studied, trifoliate leaf surface varied from 79 to 150sq. cm. Leaf area index (LAI) varied from 4.0 to 8.6 sq. m/sq. m, with optimal LAI equal to 6.0 sq. m/sq. m. Excessive LAI (over 7.7 sq. m/sq. m) decreased yield by 20 %. Optimal LAI may be achieved by various combinations of leaf size and leaf number per plant. Lines possessing good branching rate but remaining within optimal LAI values due to small leaf size were revealed. Thus, lamina size reduction may be proposed as an alternative breeding direction to solve a conflict of bushy plant type and drought tolerance.

Studies of grain production in Sorghum bicolor (L. Moench). VI.* Profiles of photosynthesis, illuminance and foliage arrangement. 4. Profiles of Photosynthesis, Illuminance and Foliage Arrangement

1976 ◽  
Vol 27 (1) ◽  
pp. 35 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson
Keyword(s):  
Leaf Surface ◽  
Canopy Structure ◽  
Light Extinction ◽  
Grain Production ◽  
Area Index ◽  
14Co2 Uptake ◽  
Total Light ◽  
Intercepted Radiation ◽  
Density Population ◽  
Sorghum Bicolor L

Grain sorghum was grown at two population densities in the field, and photosynthetic rates compared at noon. Profiles of photosynthesis were established by combining measurements of 12CO2 exchange and 14CO2 uptake. Canopy structure and light penetration were measured. Factors responsible for the superiority of the higher density population were evaluated. Photosynthesis–radiation responses of leaves were similar between the populations and there was little difference in total light interception. The high density population had leaves which were more vertically displayed, more uniformly dispersed, smaller in both length and width, and distributed over a greater height of canopy. Light was therefore more uniformly distributed down the profile, and coefficients of light extinction were lower. Associated with this was a higher leaf area index. The overall consequence was the distribution of intercepted radiation over a larger leaf surface, at a lower illuminance and therefore a higher efficiency of photosynthetic conversion, resulting in greater total photosynthesis. ___________________ ** Part V, Aust. J. Agric. Res., 26: 31 (1975).

A study of growth in swards of timothy and meadow fescue. I. Uninterrupted growth

1958 ◽  
Vol 51 (3) ◽  
pp. 347-352 ◽  
Author(s):  
R. H. M. Langer
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Leaf Size ◽  
Dry Weight ◽  
Meadow Fescue ◽  
Area Index ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Number Of Leaves ◽  
Total Dry Weight

1. Swards of S. 48 timothy and S. 215 meadow fescue growing alone or together were sampled at intervals of 3 weeks throughout the season. The number and weight of leaves, stems and ears were determined, and leaf area was estimated.2. Despite high rainfall, the total number of tillers in both species declined from the beginning of the experiment until early July, but increased again from then onwards until the original complement had been approximately restored. The number of leaves failed to show a corresponding increase in the autumn because each tiller carried fewer leaves than earlier in the year.3. In the spring total dry weight increased more rapidly in meadow fescue than in timothy which in turn out-yielded meadow fescue later in the season. Both species attained their greatest dry weight soon after ear emergence, a period which was marked by considerable crop growth and relative growth rates.4. Leaf area index reached a maximum before total dry weight had increased to its highest level, but then declined in both species. Meadow fescue differed from timothy by producing a second crop of foliage after the summer with a leaf area index of about 7. This second rise appeared to be due mainly to increased leaf size in contrast to timothy whose leaves became progressively smaller towards the end of the season.5. The differences in growth between the species discussed with reference to their dates of ear emergence which in this experiment differed by about 6 weeks.

Influence of different organic manures on growth, yield and mineral nutrient accumulation in lettuce (Lactuca sativa L.)

2021 ◽  
Vol 30 (2) ◽  
pp. 159-168
Author(s):  
Shabnur Chowdhury ◽  
MK Rahman
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Lactuca Sativa ◽  
Dry Weight ◽  
Organic Manure ◽  
Leaf Number ◽  
Nutrient Accumulation ◽  
Area Index ◽  
Organic Manures ◽  
Lactuca Sativa L

Effects of organic manures on growth and yield of lettuce (Lactuca sativa L.) and nutrient accumulation in its leaves was examined. The experiment was conducted in a completely randomized design (CRD) replicated thrice with ten treatments involving nine organic manures and a control treatment. Growth parameters viz. plant height, leaf number, leaf length, leaf area, leaf area index and fresh and dry weight of leaf, stem and root were assessed. The highest height (23.69 cm), longest leaf (32.18cm), leaf area (5883.43cm2), leaf area index (6.434), fresh weight (85.41 g) and dry weight (42.73 g) were found in Payel organic manure. The maximum leaf number (27) was recorded in Approshika organic manure. The maximum content of nitrogen (6.12%), phosphorus (1.83%), potassium (4.11%) and Sulphur (1.69%) were observed in Payel organic manure. The best growth performance and nutrient accumulation was observed in Payel organic manure. Dhaka Univ. J. Biol. Sci. 30(2): 159-168, 2021 (July)

Defoliation frequency and the response by white clover to increasing phosphorus supply 1. Leaf dry matter yield and plant morphology responses

1997 ◽  
Vol 48 (1) ◽  
pp. 111 ◽  
Author(s):  
D. K. Singh ◽  
P. W. G. Sale
Keyword(s):  
Leaf Area ◽  
White Clover ◽  
Dry Matter ◽  
Leaf Size ◽  
Plant Morphology ◽  
Application Rate ◽  
Leaf Number ◽  
Growth And Survival ◽  
Defoliation Frequency ◽  
P Supply

A glasshouse experiment was carried out to determine how an increasing P supply influences the growth and survival of white clover plants subjected to a range of defoliation frequencies. Treatments involved the factorial combination of P application rate (0, 30, 90, and 180 mg/pot) to a P-deficient Krasnozem soil and defoliation frequency (1, 2, or 4 defoliations over 36 days). The survival of P-deficient plants was threatened by the most frequent defoliation; their leaf area declined owing to a reduction in leaf number and individual leaf size with each successive defoliation. Increasing the P supply to 180 mg/pot reversed this downward trend as the high P plants were able to maintain leaf area by increasing leaf size and number. Increasing the frequency from 1 to 4 defoliations over the 36 days also changed the form of the leaf dry matter response to added P, from an asymptotic to a linear response. The P requirement of white clover for maximum leaf yield therefore increased under frequent defoliation. This effect was also apparent for a range of morphological measurements including stolon elongation rate, leaf area, root mass, leaf number, and stolon number, where the magnitude of the P response was consistently greater for frequently defoliated plants. Exceptions included stolon mass, which responded more to P addition under infrequent defoliation.

Relative importance of overstory canopy openness and seedling density on crown morphology and growth of Acer nipponicum seedlings

Botany ◽  
2012 ◽  
Vol 90 (11) ◽  
pp. 1152-1160 ◽  
Author(s):  
Waka Saito ◽  
Koji Kawamura ◽  
Hiroshi Takeda
Keyword(s):  
Leaf Area ◽  
Mass Fraction ◽  
Leaf Size ◽  
Adaptive Plasticity ◽  
Canopy Openness ◽  
Seedling Density ◽  
Seedling Morphology ◽  
Area Index ◽  
Leaf Mass ◽  
Leaf Mass Fraction

We investigated the effects of overstory canopy openness and seedling density on seedling morphology and growth in the mid-successional species Acer nipponicum Hara in a cool-temperate forest. Studied seedlings were 46 seedlings of 30–160 cm height, and their overstory canopy openness ranged between 7.2% and 17.0%. Seedling density, measured as the number of conspecific neighboring seedlings within a 50 cm radius of the target seedling, ranged between 0 and 19. There were no significant correlations between seedling height, canopy openness, and seedling density. Multiple regression analysis showed that crown depth, leaf mass fraction, and leaf area index decreased with decreasing canopy openness and increasing seedling density, while the ratio of trunk-lateral branches mass increased. Overstory canopy openness did not affect crown area, leaf size, or petiole length, all of which decreased with increasing seedling density. Standardized regression coefficients indicated that seedling density affected morphology and growth more than canopy openness did. The morphological responses to canopy openness cannot be considered as adaptive plasticity, as total leaf area and leaf mass fraction decreased with decreasing light levels. In contrast, responses to seedling density indicate adaptive responses to neighborhood competition. The results highlight the importance of seedling density that influenced seedling growth and morphology independently of overstory canopy openness.

scholarly journals Correlation and path coefficient studies of Cocoyam (Xanthosoma sagittifolium L.)

2015 ◽  
Vol 50 (1) ◽  
pp. 47-52
Author(s):  
KK Paul ◽  
MA Bari
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Leaf Length ◽  
Leaf Number ◽  
Path Coefficient ◽  
Path Coefficient Analysis ◽  
Area Index ◽  
Xanthosoma Sagittifolium ◽  
Positive Direct

Plant height, leaf length, leaf breadth, leaf number, leaf area index, corm length, corm breadth, corm weight, sucker number exhibited positive correlation with yield per plant in both genotypic and phenotypic level in cocoyam (Xanthosoma sagittifolium). Path coefficient analysis revealed that leaf length, leaf number, corm length exhibited direct influences to yield per plant. In genotypic level yield per plant showed the highest positive direct effect with corm length followed by cormel breadth, sucker number.Bangladesh J. Sci. Ind. Res. 50(1), 47-52, 2015

scholarly journals Sweet Potato Canopy Morphology: Leaf Distribution

1990 ◽  
Vol 115 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Zana C. Somda ◽  
Stanley J. Kays
Keyword(s):  
Leaf Area ◽  
Sweet Potato ◽  
Ipomoea Batatas ◽  
Plant Density ◽  
Leaf Size ◽  
Progressive Increase ◽  
Leaf Number ◽  
Petiole Length ◽  
Plant Densities ◽  
Leaf Distribution

Changes in leaf distribution of the sweet potato [Ipomoea batatas (L.) Lam.] cultivar Jewel were assessed bi-weekly for 18 weeks at three plant densities (15, 30, and 45 cm × 96-cm spacing). The distribution of leaves on the branches and the timing at which leaf number stabilized were affected by the plant density. Plant density resulted in significant differences in the number of leaves and percentage of missing leaves during the growing season. Leaf number and total leaf area varied substantially in response to plant density, but individual lamina and petiole lengths and leaf area did not vary. Average petiole and leaf lengths and leaf size increased during the season, with the maximum length and area dependent on the type of branch on which the leaf was formed. Average petiole length per branch and the susceptibility to leaf loss increased with descending branch hierarchy (secondary branch < primary branch < main stem). Leaf losses after the 4th week tended to parallel a progressive increase in petiole length of new leaves, suggesting shading as a primary cause of leaf shedding and the loss of the oldest leaves first.

scholarly journals LEAF SURFACE AREA ESTIMATION IN DIFFERENT GRAPES VARIETIES USING A AM 300 LEAF AREA METER

2018 ◽  
Author(s):  
Patrik BURG ◽  
Jana BURGOVÁ ◽  
Vladimír MAŠÁN ◽  
Miroslav VACHŮN
Keyword(s):  
Leaf Area ◽  
Surface Area ◽  
Leaf Surface ◽  
Significant Proportion ◽  
Area Index ◽  
Initial Development ◽  
Lateral Shoots ◽  
Leaf Surface Area ◽  
South Moravia ◽  
Area Development

Experimental measurements focused on evaluation of grapevine leaf surface area development in nine varieties, in the viticultural conditions of South Moravia. The dynamics of leaf surface area development was measured by using a device called leaf area meter AM 300. The device operates on the principle of a scanner and the resulting values are expressed through the leaf area index - LAI. The measurements were carried out in five dates during phenophases of growth, flowering, initial development of fruits, and ripening of berries. The results show a significant differences in increase in leaf area between the evaluated varieties, especially during flowering. The size of the leaf area, depending on the year, corresponds to values between 7.615 and 13.483 square metres per hectare. The largest leaf area was reached in growth stage 8, which is ripening of fruit. The leaf area reached the largest size in the varieties Grüner Veltliner, Zweigelt, and Sauvignon, with values ranging from 20.560 to 26.481 square metres per hectare. The results suggest that a significant proportion of leaf area is also represented by lateral shoots whose size in the ripening phase, depending on variety, ranges from 33.7 to 52.9 per cent of the total leaf area.

Improved methods for predicting individual leaf area and leaf senescence in maize (Zea mays)

1998 ◽  
Vol 49 (2) ◽  
pp. 249 ◽  
Author(s):  
C. J. Birch ◽  
G. L. Hammer ◽  
K. G. Rickert
Keyword(s):  
Leaf Area ◽  
Leaf Senescence ◽  
Leaf Length ◽  
Thermal Time ◽  
Leaf Number ◽  
Area Index ◽  
Plant Leaf ◽  
Individual Leaf ◽  
Total Leaf ◽  
Maximum Temperatures

The ability to predict leaf area and leaf area index is crucial in crop simulation models that predict crop growth and yield. Previous studies have shown existing methods of predicting leaf area to be inadequate when applied to a broad range of cultivars with different numbers of leaves. The objectives of the study were to (i) develop generalised methods of modelling individual and total plant leaf area, and leaf senescence, that do not require constants that are specific to environments and/or genotypes, (ii) re-examine the base, optimum, and maximum temperatures for calculation of thermal time for leaf senescence, and (iii) assess the method of calculation of individual leaf area from leaf length and leaf width in experimental work. Five cultivars of maize differing widely in maturity and adaptation were planted in October 1994 in south-eastern Queensland, and grown under non-limiting conditions of water and plant nutrient supplies. Additional data for maize plants with low total leaf number (12-17) grown at Katumani Research Centre, Kenya, were included to extend the range in the total leaf number per plant. The equation for the modified (slightly skewed) bell curve could be generalised for modelling individual leaf area, as all coefficients in it were related to total leaf number. Use of coefficients for individual genotypes can be avoided, and individual and total plant leaf area can be calculated from total leaf number. A single, logistic equation, relying on maximum plant leaf area and thermal time from emergence, was developed to predict leaf senescence. The base, optimum, and maximum temperatures for calculation of thermal time for leaf senescence were 8, 34, and 40ºC, and apply for the whole crop-cycle when used in modelling of leaf senescence. Thus, the modelling of leaf production and senescence is simplified, improved, and generalised. Consequently, the modelling of leaf area index (LAI) and variables that rely on LAI will be improved. For experimental purposes, we found that the calculation of leaf area from leaf length and leaf width remains appropriate, though the relationship differed slightly from previously published equations.

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