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

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 619e-619
Author(s):  
Jens-Norbert Wünsche ◽  
Alan N. Lakso ◽  
Steven S. Denning ◽  
Terence L. Robinson

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.

1996 ◽  
Vol 121 (5) ◽  
pp. 886-893 ◽  
Author(s):  
Jens N. Wünsche ◽  
Alan N. Lakso ◽  
Terence L Robinson ◽  
Fritz Lenz ◽  
Steven S. Denning

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.


HortScience ◽  
2000 ◽  
Vol 35 (7) ◽  
pp. 1202-1206 ◽  
Author(s):  
Jens N. Wünsche ◽  
Alan N. Lakso

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.


HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 272-276 ◽  
Author(s):  
Jens N. Wünsche ◽  
Alan N. Lakso ◽  
Terence L. Robinson

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.


1991 ◽  
Vol 116 (2) ◽  
pp. 188-194 ◽  
Author(s):  
Terence L. Robinson ◽  
Alan N. Lakso

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.


Crop Science ◽  
1998 ◽  
Vol 38 (3) ◽  
pp. 827-834 ◽  
Author(s):  
I. C. Madakadze ◽  
B. E. Coulman ◽  
P. Peterson ◽  
K. A. Stewart ◽  
R. Samson ◽  
...  

2020 ◽  
Vol 25 (3) ◽  
pp. 505-525 ◽  
Author(s):  
Seeram Ramakrishna ◽  
Alfred Ngowi ◽  
Henk De Jager ◽  
Bankole O. Awuzie

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.


2020 ◽  
Vol 6 (9) ◽  
pp. 5274-5280
Author(s):  
Sorout Shalini ◽  
Derek S. Frank ◽  
Ali H. Aldoukhi ◽  
Sami E. Majdalany ◽  
William W. Roberts ◽  
...  

2021 ◽  
Vol 483 ◽  
pp. 118908
Author(s):  
Mizanur Rahman ◽  
Masum Billah ◽  
Md Obydur Rahman ◽  
Debit Datta ◽  
Muhammad Ahsanuzzaman ◽  
...  

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