The Bases of Productivity in Apple Production Systems: The Role of Light Interception by Different Shoot Types

Although apple (Malus domestica Borkh.) system yield differences are generally related to whole-canopy light interception, this study tested the hypothesis that these orchard yields are related primarily to total light intercepted by the spur canopy. Seasonal leaf area development of different shoot types, exposed bourse shoot leaf net photosynthesis, fruit growth, whole canopy light interception (by image analysis of fisheye photographs) and relative light interception by different shoot types (by a laser assisted canopy scanning device) were estimated within four 14-year-old `Empire' apple production systems (slender spindle/M.9, central leader/M.7, central leader/M.9/MM.111 and Y-trellis/M.26). The final LAI values were CL/M.7 = 1.8, CL/9/111 = 2.3, SS/M.9 = 2.6 and Y/M.26 = 3.6. Exposed leaf net photosynthesis showed few differences and was not dependent upon the production system. Yields of the pyramidal shaped tree forms were 40 to 42 t·ha-1 while Y-trellis produced 59 t·ha-1, with similar fruit sizes. Again, yields were primarily related to the percentage of light intercepted by the whole canopy, 48% to 53% for conic forms versus 62% for the Y-trellis system. Laser analyses showed that the Y-trellis system intercepted about 20% to 30% more light with the spur canopy than the conic tree forms, supporting the hypothesis. Yields were better correlated with spur canopy LAI and spur canopy light interception than with extension shoot canopy LAI and light interception.

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PRODUCTIVITY IN APPLE PRODUCTION SYSTEMS: THE ROLE OF LIGHT INTERCEPTION BY DIFFERENT SHOOT TYPES

HortScience ◽

10.21273/hortsci.27.6.619e ◽

1992 ◽

Vol 27 (6) ◽

pp. 619e-619

Author(s):

Jens-Norbert Wünsche ◽

Alan N. Lakso ◽

Steven S. Denning ◽

Terence L. Robinson

Keyword(s):

Production Systems ◽

Light Interception ◽

Leaf Photosynthesis ◽

Total Light ◽

Slender Spindle ◽

Significant Yield ◽

Apple Production ◽

Role Of Light ◽

Area Development

A 14-year-old trial of `Empire' apple production systems (Slender Spindle/M9, Central Leaders on M7 and 9/111 interstems, and Y-trellis/M26) had shown significant yield differences that were primarily related to total light interception, but yield of fruit/MJ light interception, however, was still higher in the Y-trellis. The hypothesis tested was that in healthy orchards yields are related primarily tototal light intercepted by the spur canopy. In 1991 seasonal leaf area development, exposed leaf photosynthesis, fruit growth, total light interception (by image analysis of fisheye photos) and relative light interception by different shoot types (by a laser sunbeam simulator) were estimated. The results reflected the mature, spurry nature of these trees. The final LAI values were CL/7=1.8, CL/9/111=2.3, SS/9=2.6 and Y/26=3.6. Exposed leaf photosynthesis showed few differences. Yields of the pyramid forms were 40-42 t/ha while Y-trellis gave 59 t/ha, with similar fruit sizes. Again, yields were primarily related to % total light interception (48-53% for pyramid forms versus 62% for the Y). Laser analyses showed that the Y intercepted more light with the spur canopy than the pyramid forms, supporting the hypothesis. Yields were better correlated with spur canopy LAI and spur canopy light interception than with shoot canopy LAI and light interception.

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The Relationship Between Leaf Area and Light Interception by Spur and Extension Shoot Leaves and Apple Orchard Productivity

HortScience ◽

10.21273/hortsci.35.7.1202 ◽

2000 ◽

Vol 35 (7) ◽

pp. 1202-1206 ◽

Cited By ~ 49

Author(s):

Jens N. Wünsche ◽

Alan N. Lakso

Keyword(s):

Leaf Area ◽

Production Systems ◽

Light Interception ◽

Apple Orchard ◽

Fruit Yield ◽

Area Index ◽

Canopy Development ◽

Slender Spindle ◽

The Relationship ◽

Canopy Light Interception

The study evaluated the relationship of spur vs. extension shoot leaf area and light interception to apple (Malus {XtimesX}domesticaBorkh.) orchard productivity. Fifteen-year-old `Marshall McIntosh'/M.9 trees had significantly greater leaf area and percentage of light interception at 3-5 and 10-12 weeks after full bloom (AFB) than did 4-year-old `Jonagold'/Mark trees. Despite significant increases in leaf area and light interception with canopy development, linear relationships between total, spur, and extension shoot canopy leaf area index (LAI) and 1) light interception and 2) fruit yield were similar at both times. Mean total and spur canopy LAI and light interception were significantly and positively correlated with fruit yield; however, extension shoot LAI and light interception were poorly correlated with yield. In another study total, spur and extension shoot canopy light interception varied widely in five apple production systems: 15-year-old central leader `Redchief Delicious' MM.111, 15-year-old central leader `Redchief Delicious' MM.111/M.9, 16-year-old slender spindle `Marshall McIntosh' M.9, 14-year-old `Jerseymac' M.9 on 4-wire trellis, and 17-year-old slender spindle `MacSpur' M.9. Yields in these orchards were curvilinearly related to total and extension shoot canopy light interception and decreased when total light interception exceeded 60% and extension shoot interception exceeded 25%. Fruit yields were linearly and highly correlated (r2 = 0.78) with spur light interception. The findings support the hypothesis that fruit yields of healthy apple orchards are better correlated with LAI and light interception by spurs than by extension shoots. The results emphasize the importance of open, well-illuminated, spur-rich tree canopies for high productivity.

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589 Summer Pruning Effects on Leaf and Whole Canopy Gas Exchange in Apple Trees

HortScience ◽

10.21273/hortsci.34.3.548c ◽

1999 ◽

Vol 34 (3) ◽

pp. 548C-548

Author(s):

Kuo-Tan Li ◽

Alan N. Lakso

Keyword(s):

Photosynthetic Activity ◽

Fruit Size ◽

Light Interception ◽

Light Penetration ◽

Apple Trees ◽

Carbon Supply ◽

Shade Leaves ◽

Reduced Light ◽

Canopy Light Interception

Summer pruning is primarily used in apples to increase the light penetration into inner canopy to improve fruit color. However, summer pruning may reduce fruit size. We hypothesize that removing healthy exterior shoots reduces the whole-tree carbon supply in relation to pruning severity. If the crop load (i.e., demand) is high, fruit size and quality will be reduced. The effects of summer pruning on photosynthetic activity and recovery of shaded leaves after re-exposure were monitored on a range of exposures in canopies of `Empire' apple trees. The photosynthetic ability of leaves was positively related to its prepruning exposure. There was little recovery of photosynthetic activity of shade leaves until late growing season, indicating the re-exposure of shade leaves after summer pruning cannot replace the role of exterior leaves removed by pruning. Whole canopy net CO2 exchange (NCER) was measured on `Empire'/M9 trees with a commercial range of pruning severity. Reductions in NCER were approximately proportional to pruning severity and % leaf area removed and were as great as 60% in the most severe pruning. Canopy light interception decreased slightly. The effects on canopy NCER thus appeared to be primarily related to reduced photosynthetic efficiency and secondarily to reduced light interception.

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Comparison of Four Methods for Estimating Total Light Interception by Apple Trees of Varying Forms

HortScience ◽

10.21273/hortsci.30.2.272 ◽

1995 ◽

Vol 30 (2) ◽

pp. 272-276 ◽

Cited By ~ 29

Author(s):

Jens N. Wünsche ◽

Alan N. Lakso ◽

Terence L. Robinson

Keyword(s):

Grid Method ◽

Time Of Day ◽

Light Interception ◽

Radiation Balance ◽

Atmospheric Conditions ◽

Apple Trees ◽

Tree Form ◽

Total Light ◽

Slender Spindle ◽

Highly Correlated

Four methods of estimating daily light interception (fisheye photography with image analysis, multiple-light sensors, ceptometer, and point grid) were compared using various apple (Malus domestica Borkh.) tree forms: slender spindle, Y- and T-trellises, and vertical palmette. Interactions of tree form, time of day, and atmospheric conditions with light interception estimates were examined. All methods were highly correlated to each other (r2 > 0.92) for estimated daily mean percent total light interception by the various tree forms, except that the point grid method values were slightly lower. Interactions were found among tree form, time of day, and diffuse/direct radiation balance on estimated light interception, suggesting that several readings over the day are needed under clear skies, especially in upright canopies. The similar results obtained by using the point grid method (counting shaded/exposed points on a grid under the canopy) on clear days may allow rapid, simple, and inexpensive estimates of orchard light interception.

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Bases of Yield and Production Efficiency in Apple Orchard Systems

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.116.2.188 ◽

1991 ◽

Vol 116 (2) ◽

pp. 188-194 ◽

Cited By ~ 49

Author(s):

Terence L. Robinson ◽

Alan N. Lakso

Keyword(s):

Conversion Efficiency ◽

Production Efficiency ◽

Light Interception ◽

Apple Orchard ◽

Tree Canopy ◽

Canopy Architecture ◽

Cross Sectional ◽

Canopy Volume ◽

Total Light ◽

Slender Spindle

Bases of orchard productivity were evaluated in four 10-year-old apple orchard systems (`Empire' and `Redchief Delicious' Malus domestics Borkh. on slender spindle/M.9, Y-trellis/M.26, central leader/M.9/MM.111, and central leader/M.7a). Trunk cross-sectional areas (TCA), canopy dimension and volume, and light interception were measured. Canopy dimension and canopy volume were found to be relatively poor estimators of orchard light interception or yield, especially for the restricted canopy of the Y-trellis. TCA was correlated to both percentage of photosynthetically active radiation (PAR) intercepted and yields. Total light interception during the 7th to the 10th years showed the best correlation with yields of the different systems and explained most of the yield variations among systems. Average light interception was highest with the Y-trellis/M.26 system of both cultivars and approached 70% of available PAR with `Empire'. The higher light interception of this system was the result of canopy architecture that allowed the tree canopy to grow over the tractor alleys. The central leader/M.7a had the lowest light interception with both cultivars. The efficiency of converting light energy into fruit (conversion efficiency = fruit yield/light intercepted) was significantly higher for the Y-trellis/M.26 system than for the slender spindle/M.9 or central leader/M.9/MM.111 systems. The central leader/M.7a system bad the lowest conversion efficiency. An index of partitioning was calculated as the kilograms of fruit per square centimeter increase in TCA. The slender spindle/M.9 system had significantly higher partitioning index than the Y-trellis/M.26 or central leader/M.9/MM.111. The central leader/M.7a system had the lowest partitioning index. The higher conversion efficiency of the Y/M.26 system was not due to increased partitioning to the fruit; however, the basis for the greater efficiency is unknown. The poor conversion efficiency of the central leader/M.7a was mostly due to low partitioning to the fruit. The Y-trellis/M.26 system was found to be the most efficient in both intercepting PAR and converting that energy into fruit.

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The Role of Light Anhydrous Silicic Acid on Physical Stability of Troglitazone Solid Dispersion

10.26226/morressier.57d6b2b5d462b8028d88d31e ◽

2016 ◽

Author(s):

Toshiyuki Nakahashi

Keyword(s):

Silicic Acid ◽

Solid Dispersion ◽

Physical Stability ◽

Role Of Light

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The Salt of Ba : Reflections on the Role of the "Peripheries" in the Production Systems of Bronze Age China

Arts asiatiques ◽

10.3406/arasi.2006.1638 ◽

2006 ◽

Vol 61 (1) ◽

pp. 45-56

Author(s):

Lothar Falkenhausen

Keyword(s):

Bronze Age ◽

Production Systems

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Emerging Industrial Revolution: Symbiosis of Industry 4.0 and Circular Economy: The Role of Universities

Science Technology and Society ◽

10.1177/0971721820912918 ◽

2020 ◽

Vol 25 (3) ◽

pp. 505-525 ◽

Cited By ~ 4

Author(s):

Seeram Ramakrishna ◽

Alfred Ngowi ◽

Henk De Jager ◽

Bankole O. Awuzie

Keyword(s):

Economic Growth ◽

Circular Economy ◽

Industry 4.0 ◽

Business Models ◽

Industrial Revolution ◽

New Technologies ◽

Production Systems ◽

Fourth Industrial Revolution ◽

New Jobs

Growing consumerism and population worldwide raises concerns about society’s sustainability aspirations. This has led to calls for concerted efforts to shift from the linear economy to a circular economy (CE), which are gaining momentum globally. CE approaches lead to a zero-waste scenario of economic growth and sustainable development. These approaches are based on semi-scientific and empirical concepts with technologies enabling 3Rs (reduce, reuse, recycle) and 6Rs (reuse, recycle, redesign, remanufacture, reduce, recover). Studies estimate that the transition to a CE would save the world in excess of a trillion dollars annually while creating new jobs, business opportunities and economic growth. The emerging industrial revolution will enhance the symbiotic pursuit of new technologies and CE to transform extant production systems and business models for sustainability. This article examines the trends, availability and readiness of fourth industrial revolution (4IR or industry 4.0) technologies (for example, Internet of Things [IoT], artificial intelligence [AI] and nanotechnology) to support and promote CE transitions within the higher education institutional context. Furthermore, it elucidates the role of universities as living laboratories for experimenting the utility of industry 4.0 technologies in driving the shift towards CE futures. The article concludes that universities should play a pivotal role in engendering CE transitions.

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115 Nitrogen fertilizer effects on above ground sward characteristics and beef heifer performance from native warm-season grass blends

Journal of Animal Science ◽

10.1093/jas/skz397.060 ◽

2020 ◽

Vol 98 (Supplement_2) ◽

pp. 26-27

Author(s):

Caroline Chappell ◽

Landon Marks ◽

Katie Mason ◽

Mary K Mullenix ◽

Sandra L Dillard ◽

...

Keyword(s):

Nutritive Value ◽

Warm Season ◽

Ground Cover ◽

Application Rate ◽

Light Interception ◽

Botanical Composition ◽

Forage Production ◽

Beef Heifers ◽

Fertilizer Application Rate ◽

Canopy Light Interception

Abstract A 2-yr study was conducted at Black Belt Research and Extension Center in Marion Junction, AL, to evaluate the effect of nitrogen (N) fertilizer application rate on forage production characteristics, nutritive value, and animal performance of beef heifers grazing a mixture of native warm-season grasses (NWSG) including big bluestem, little bluestem, and indiangrass. Six, two-hectare plots were randomly assigned to one of two treatments (0 or 67 kg N ha-1 applied in early April; n = 3 replications per treatment). Paddocks were continuously stocked with four weaned Angus × Simmental beef heifers (initial BW 288 ± 7 kg) from late May/early June through mid-to-late August during 2018 (73 grazing d) and 2019 (70 grazing d), respectively. Put-and-take cattle were used to manage forage to a target of 38 cm. Forage mass and canopy heights were collected every two weeks during the trial. Visual ground cover ratings, canopy light interception, and botanical composition were measured at the beginning and end of the trial in each year. Hand-plucked samples were collected every two weeks during the grazing trial to determine forage nutritional value. Data were analyzed using the PROC MIXED procedure in SAS 9.4, and differences were declared significant when P ≤ 0.05. Nitrogen fertilized NWSG had greater crude protein (P < 0.0001), sward heights (P = 0.0003), and canopy light interception at the beginning of the season (P = 0.0049) compared to non-fertilized paddocks. However, there were no differences (P ≥ 0.05) among N-fertility treatments for mean forage mass, heifer ADG, or BCS across the 2-yr study. Botanical composition data indicated that indiangrass decreased from 64% to 61% (P = 0.0022) and weed pressure increased from 11% to 15% (P = 0.0064) across the summer grazing season. Canopy light interception decreased by 51% from early June to August in fertilized NWSG and 26% in unfertilized paddocks, respectively. These data illustrate that NWSG systems may provide a viable grazing system in the summer months under reduced N inputs.

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