scholarly journals Optimization of Light Interception, Leaf Area and Yield in “WA38”: Comparisons among Training Systems, Rootstocks and Pruning Techniques

Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 689 ◽  
Author(s):  
Brendon Anthony ◽  
Sara Serra ◽  
Stefano Musacchi
Keyword(s):  
Leaf Area ◽  
Management Strategy ◽  
New Technologies ◽  
Light Interception ◽  
Alternate Bearing ◽  
Area Index ◽  
Training Systems ◽  
Optimal Thresholds ◽  
Proper Training ◽  
Pruning Techniques

As apple orchards have transitioned to high-density plantings, proper training systems are required to manage increased leaf area. Leaf area index (LAI) is defined as the ratio between leaf area to ground area (m2/m2) and can infer orchard health, light relationships and productivity. New technologies enable rapid assessments of LAI and light interception (LI) in the orchard. In this study, LAI, LI, and productivity were assessed across two training systems (Spindle and V), two rootstocks (Geneva 41® (G41) and Malling 9—Nic29 (Nic29)) and two pruning techniques (“click” and bending) in 2016 and 2017. The objective of this study was to determine a management strategy for “WA38” to meet optimal levels for LAI (1.2–2.0) and light interception (65–75%). Higher light interception was measured in V compared to Spindle and in G41 compared to Nic29 in both years. Minimal differences in LAI and light interception were detected across pruning techniques. In “WA38” the “click” technique maintained more consistent yields than bending. In both years, the Spindle-Nic29-“click” combination maintained optimal thresholds for LAI (1.93 and 1.48), light interception (66% and 68%) and consistent yields. This sequence helps mitigate “blind wood” and alternate bearing, while optimizing leaf area and light in “WA38”.

scholarly journals Varying Density with Constant Rectangularity: I. Effects on Apple Tree Growth and Light Interception in Three Training Systems over Ten Years

HortScience ◽  
2004 ◽  
Vol 39 (3) ◽  
pp. 501-506 ◽  
Author(s):  
Cheryl R. Hampson ◽  
Harvey A. Quamme ◽  
Frank Kappel ◽  
Robert T. Brownlee
Keyword(s):  
Leaf Area ◽  
Tree Height ◽  
Light Interception ◽  
Training System ◽  
Influential Factor ◽  
Planting Density ◽  
Area Index ◽  
Training Systems ◽  
Slender Spindle ◽  
Plot Design

The effect of increasing planting density at constant rectangularity on the vegetative growth and light interception of apple [Malus ×sylvestris (L) var. domestica (Borkh.) Mansf.] trees in three training systems (slender spindle, tall spindle, and Geneva Y trellis) was assessed for 10 years. Five tree densities (from 1125 to 3226 trees/ha) and two cultivars (Royal Gala and Summerland McIntosh) were tested in a fully guarded split-split plot design. Planting density was the most influential factor. As tree density increased, tree size decreased, and leaf area index and light interception increased. A planting density between 1800 and 2200 trees/ha (depending on training system) was needed to achieve at least 50% light interception under the conditions of this trial. Training system altered tree height and canopy diameter, but not total scion weight. Training system began to influence light interception in the sixth leaf, when the Y trellis system intercepted more light than either spindle form. Trees trained to the Y trellis tended to have more spurs and a lower proportion of total leaf area in shoot leaves than the other two systems. The slender and tall spindles were similar in most aspects of performance. Tall spindles did not intercept more light than slender spindles. `Royal Gala' and `Summerland McIntosh' trees intercepted about the same amount of light. `Royal Gala' had greater spur leaf area per tree than `Summerland McIntosh', but the cultivars were similar in shoot leaf area per tree and spur density.

scholarly journals Modeling light interception and distribution in mixed canopy of common cocklebur (Xanthium stramarium) in competition with corn

2010 ◽  
Vol 28 (3) ◽  
pp. 455-462 ◽  
Author(s):  
F. Vazin ◽  
M. Hassanzadeh ◽  
A. Madani ◽  
M. Nassiri-Mahallati ◽  
M. Nasri
Keyword(s):  
Leaf Area ◽  
Extinction Coefficient ◽  
Distribution Density ◽  
Yield Loss ◽  
Light Interception ◽  
Area Index ◽  
Corn Seed ◽  
Parabolic Function ◽  
Triangular Function ◽  
Height Model

The aim of this study was to model light interception and distribution in the mixed canopy of Common cocklebur (Xanthium stramarium) with corn. An experiment was conducted in factorial arrangement on the basis of randomized complete blocks design with three replications in Gonabad in 2006-2007 and 2007-2008 seasons. The factors used in this experiment include corn density of 7.5, 8.5 and 9.5 plants per meter of row and density of Common cocklebur of zero, 2, 4, 6 and 8 plants per meter of row. INTERCOM model was used through replacing parabolic function with triangular function of leaf area density. Vertical distribution of the species' leaf area showed that corn has concentrated the most leaf area in layer of 80 to 100 cm while Common cocklebur has concentrated in 35-50 cm of canopy height. Model sensitivity analysis showed that leaf area index, species' height, height where maximum leaf area is seen (hm), and extinction coefficient have influence on light interception rate of any species. In both species, the distribution density of leaf area at the canopy length fit a triangular function, and the height in which maximum leaf area was observed was changed by change in density. There was a correlation between percentage of the radiation absorbed by the weed and percentage of corn seed yield loss (r² = 0.89). Ideal type of corn was determined until the stage of tasseling in competition with weed. This determination indicates that the corn needs more height and leaf area, as well as less extinction coefficient to successfully fight against the weed.

Effect of residual leaf area index on spatial components of Tifton 85 pastures and ingestive behaviour of sheep

2017 ◽  
Vol 57 (5) ◽  
pp. 903 ◽  
Author(s):  
W. L. Silva ◽  
J. P. R. Costa ◽  
G. P. Caputti ◽  
A. L. S. Valente ◽  
D. Tsuzukibashi ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Rainy Season ◽  
Structural Characteristics ◽  
Light Interception ◽  
Dry Season ◽  
Area Index ◽  
Dead Material ◽  
Point Quadrat ◽  
Ingestive Behaviour

This study compared the effect of residual leaf area index (rLAI) on the spatial distribution of morphological components of Tifton 85 (Cynodon spp.) pastures and the ingestive behaviour of grazing sheep. Also, it was investigated whether any specific correlation could be found between pasture structural characteristics and sheep ingestive behaviour. Four rLAI treatments (0.8; 1.4; 2.0 and 2.6) with four replications were evaluated per period. Sheep grazed under rotational stocking management and they grazed for 4 days in each pasture while pasture regrowth period was determined by the 95% light interception requirement. Pasture structure was evaluated using inclined point-quadrat, LAI estimates, light interception and leaf : stem ratio. The 2.6 rLAI yielded the highest proportion of dead material in the lower canopy. In the post-grazing period the proportion of leaves increased with increasing rLAI, especially on the canopy surface during the rainy season. In the pre-grazing average pasture height ranged between 19 and 26 cm with dead material and stem observed up to the canopy surface in the dry season. The animals grazed longer on the last day (89.72%) compared with the first day (80.25%) in the dry season. However, they spent less time (11.45%) ruminating in the dry season compared with the rainy season (15.38%), regardless of the grazing day. Grazing time decreased and rumination time increased as rLAI increased. Sheep grazing time correlated negatively with pasture height, before and after grazing. The sheep tend to graze longer on Tifton 85 pastures when rLAI was lower and forage supply was possibly less as on the last grazing day and in the dry season.

scholarly journals Effect of Spatial-Temporal Light Competition on Cotton Yield and Yield Distribution

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2346
Author(s):  
Qingru Wang ◽  
Huanxuan Chen ◽  
Yingchun Han ◽  
Fangfang Xing ◽  
Zhanbiao Wang ◽  
...  
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Retention Rate ◽  
Block Design ◽  
Light Interception ◽  
Planting Density ◽  
Cotton Yield ◽  
Light Competition ◽  
Area Index ◽  
Yield Distribution

The photosynthetically active radiation (PAR) of crop canopy is highly related to yield formation, but how it relates to yield and yield distribution is not well understood. The focus of this study was to explore the relationship between light competition under different densities and yield distributions of cotton. The experiment was conducted in 2019 and 2020 at the Cotton Research Institute of the Chinese Academy of Agricultural Sciences in Anyang city, Henan Province, China. A randomized block design was employed, with a total of three repeats. Each repeat had six density treatments: D1: 15,000; D2: 33,000; D3: 51,000; D4: 69,000; D5: 87,000; and D6: 105,000 plants·ha−1. As predicted, the results showed that the canopy light interception, leaf area index, plant height, and biomass of high-density cotton were higher than those of low-density cotton. The aboveground biomass produced by D6 was the highest, and was 12.9, 19.5, 25.4, 46.3, and 69.2% higher in 2019 and 14.3, 19.9, 32.5, 53.7, and 109.9% higher in 2020 than D5, D4, D3, D2, and D1, respectively. Leaf area, plant height, biomass, boll number, and boll weight were significantly correlated with the light interception rate. D5 (87,000 plants·ha−1) had a higher light interception rate and the highest yield. The highest lint yields produced by D5 were 1673.5 and 1375.4 kg·ha−1 in two years, and was 3.2, 4.3, 5.6, 9.7, and 24.7% higher in 2019, and 6.8, 10.6, 13.5, 21.5, and 34.4% higher in 2020 than D6, D4, D3, D2, and D1, respectively. The boll retention of the lower fruit branch under D5 reached 0.51 and 0.57 in two years, respectively. The shedding rate of the upper fruit branch decreased with the increase in cotton density in two years. The boll retention rate and shedding rate in the lower part of cotton plants were most closely related to light interception, with R2 values of 0.91 and 0.96, respectively. Our study shows cotton yield could be improved through higher light interception by optimizing planting density and canopy structure.

scholarly journals Components of the leaf area index of marandu palisadegrass swards subjected to strategies of intermittent stocking

2009 ◽  
Vol 66 (6) ◽  
pp. 721-732 ◽  
Author(s):  
Alessandra Aparecida Giacomini ◽  
Sila Carneiro da Silva ◽  
Daniel Oliveira de Lucena Sarmento ◽  
Cauê Varesqui Zeferino ◽  
Júlio Kuhn da Trindade ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Management Practices ◽  
Block Design ◽  
Early Spring ◽  
Light Interception ◽  
Area Index ◽  
Early Return ◽  
Index Site

Leaf area index is the main sward characteristic related to the processes of light interception and competition in plant communities. The objective of this experiment was to quantify and evaluate the composition of the leaf area on tillers of marandu palisadegrass (Brachiaria brizantha cv. Marandu) subjected to strategies of intermittent stocking. The experiment was carried out in Piracicaba, state of São Paulo, Brazil, from October/2004 to December/2005. Swards were grazed at 95 and 100% canopy light interception (LI) to post-grazing heights of 10 and 15 cm, following a 2 ' 2 factorial arrangement with four replications in a randomised complete block design. Estimates were made of sward leaf area index, site filling, specific leaf area and the dimensionless ratio between tiller leaf area and volume (R), as well as the relative contribution of basal and aerial tillers to these variables. In early spring, values of leaf area index and specific leaf area were low when compared to the other seasons, and swards grazed at 95% LI presented higher site filling and specific leaf area than those grazed at 100% LI. This resulted in higher tillering activity and increase in leaf area index in late spring, indicating quick recovery and early return of swards grazed at 95% LI to growing conditions. Aerial tillers corresponded to an important morphological adaptation of marandu palisadegrass to increase its competitive ability. Treatment 100/10 resulted in the highest and 95/15 in the lowest R values throughout the experiment, suggesting an allometric pattern of growth of tillers during regrowth in order to compensate low tiller population and optimise the leaf area index. Grazing management practices can benefit from this knowledge by promoting ideal sward conditions to maximise and accelerate growth.

scholarly journals Climate change and vine training systems: the influence different spatial distribution of shoots may have on sugar accumulation in Sangiovese grapevines.

2019 ◽  
Vol 13 ◽  
pp. 04006 ◽  
Author(s):  
Gabriele Valentini ◽  
Gianluca Allegro ◽  
Chiara Pastore ◽  
Emilia Colucci ◽  
Eugenio Magnanini ◽  
...  
Keyword(s):  
Climate Change ◽  
Leaf Area ◽  
Light Interception ◽  
Training System ◽  
Soluble Solids ◽  
Sugar Accumulation ◽  
Stem Water Potential ◽  
Negative Consequences ◽  
Training Systems ◽  
Open Canopy

The choice of training system may influence vineyard efficiency in terms of light interception and water consumption, particularly in the current context of climate change. On this basis, during the 2017 season, Sangiovese potted vines were grown outdoors using two different training systems: guyot vertical shoot positioned system (C) and V-shaped open canopy (A). From the end of June until September, vine transpiration was continuously monitored by the gravimetric approach and at different times in the season, the leaf area, light interception, photosynthetic activity and stem water potential were measured. Grape yield and fruit composition were recorded at harvest. C plants did not differ from A in terms of leaf area during the entire season. Light interception was higher in C vines during the early hours of the morning and lower in the central part of the day and the transpiration loss was higher, as was the net photosynthesis detected on some days in August. No differences were detected in terms of yield but a significant increase in soluble solids was found in C compared to A. The open canopy compared to a closed one, in a particularly hot year like 2017, resulted in negative consequences on the accumulation of soluble solids, probably as a result of the radiative stress suffered by the A vines in the middle hours of the day.

scholarly journals Cluster and Principle Component Analysis of Soybean Grown at Various Row Spacings, Planting Dates and Plant Populations

2018 ◽  
Vol 3 (1) ◽  
pp. 110-121 ◽  
Author(s):  
Charanjit Singh Kahlon ◽  
Bin Li ◽  
James Board ◽  
Mahendra Dia ◽  
Parmodh Sharma ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Light Interception ◽  
Plant Population ◽  
Large Set ◽  
Planting Dates ◽  
Area Index ◽  
Principle Components Analysis

Abstract Increased light interception (LI), along with concomitant increases in crop growth rate (CGR), is the main factor explaining how cultural factors such as row spacing, plant population, and planting date affect soybean yield. Leaf area index (LAI), LI, and CGR are interrelated in a “virtuous spiral” where increased LAI leads to greater LI resulting in a higher CGR and more total dry matter per area (TDM). This increases LAI, thus accelerating the entire physiological process to a higher level. A greater understanding of this complex growth dynamic process could be achieved through use of cluster analysis and principle components analysis (PCA). Cluster analysis involves grouping of similar objects in such way that objects in same cluster are similar to each other and dissimilar to objects in other cluster. PCA is a technique used to reduce a large set of variables to a few meaningful ones. Seasonal relative leaf area index (RLAI), relative light interception (RLI), and relative total dry matter (RTDM) response curves were determined from the data by a stepwise regression analysis in which these parameters were regressed against relative days after emergence (RDAE). Greatest levels of RLAI, RLI and RTDM were observed in soybean planted early on narrow row spacings and recorded greater plant population. In contrast, lower levels of these parameters occurred on plants with wide row spacings at late planting dates. For farmers, these results are useful in terms of adopting certain cultural practices which can help in the management of stress in soybean.

CANOPY CHARACTERISTICS OF CONTRASTING CLONES OF CACAO (THEOBROMA CACAO)

2002 ◽  
Vol 38 (3) ◽  
pp. 359-367 ◽  
Author(s):  
A. J. Daymond ◽  
P. Hadley ◽  
R. C. R. Machado ◽  
E. Ng
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Theobroma Cacao ◽  
Light Interception ◽  
Canopy Architecture ◽  
Mature Trees ◽  
Area Index ◽  
Mean Values ◽  
Extinction Coefficients ◽  
The Relationship

Canopy characteristics (leaf area index, fractional light interception, extinction coefficient) of mature trees of ten clonally propagated cacao cultivars were measured over a period of 14 months at an experiment site in Bahia, Brazil. Differences in leaf area index between clones became more pronounced over time. When an approximately constant leaf area index was reached (after about nine months), the leaf area index varied between clones from 2.8 to 4.5. Clonal differences in the relationship between leaf area index and fractional light interception implied differences in canopy architecture, as reflected by the range of extinction coefficients (mean values ranged from 0.63 for the clone TSH-565 to 0.82 for CC-10). The results demonstrate the potential for breeding more photosynthetically efficient cacao canopies.

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