Growth and yield of clonal guavas in south-eastern Queensland

Five processing guava clones (GA6- 1, GA7- 12, GA8-30, GA9-35, GA11-56) were tested over 3 cropping years at Nambour, in coastal south-eastern Queensland. Mean marketable yield for the first crop at 2 years of age was 45 kg/tree or 36.23 t/ha at a density of 805 trees/ha. GA11-56, the most acceptable clone for processing, also gave the highest marketable yields of 627, 71.65 and 72.53 t/ha for the first 3 crops. Yield per unit cross sectional area of trunk was a more simple and useful index of yield efficiency than more complex parameters including a fruitfulness index and multiple regressions with yield of north-south canopy spread, number of primary branches and combinations of these and trunk girth. Similarly, trunk - - girth provided at least as good an estimate of tree size as the vigour index. Tree dimension measurements which included east-west canopy spread, north-south canopy spread, tree height, stem height, number of primary branches, crown height, crown radius, tree canopy volume, canopy surface area and an index of crown weight provided no consistent indication of tree size. They were not highly correlated with either accumulated or final yield of the guava. The GA11-56 clone because of its yield, fruit size and other desirable processing characteristics was the only clone that could be recommended for commercial plantings.

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FERTILIZER EFFECTS ON EARLY GROWTH AND YIELD OF 'HAMLIN' ORANGE TREES

HortScience ◽

10.21273/hortsci.27.6.595b ◽

1992 ◽

Vol 27 (6) ◽

pp. 595b-595

Author(s):

Thomas A. Obreza ◽

Robert E. Rouse

Keyword(s):

Maximum Rate ◽

Fruit Yield ◽

Tree Canopy ◽

Poncirus Trifoliata ◽

Soluble Solids ◽

Growth And Yield ◽

Fertilizer Rate ◽

Cross Sectional ◽

Canopy Volume ◽

K Fertilizer

The growth response of newly-planted 'Hamlin' orange (“Citrus sinensis L. Osbeck) on Carrizo citrange (C. sinensis × Poncirus trifoliata L. Raf.) trees to N-P-K fertilizer rates was studied to determine the minimum fertilizer required to bring trees into maximum early production. The highest fertilizer rate applied was 2.72, 5.45, and 8.17 kg·tree-1 of an 8-1.8-6.6 N-P-K fertilizer in 1989, 1990, and 1991, respectively. Additional fertilizer treatments equalled 50, 25, or 13% of the maximum rate. The response of trunk cross-sectional area, tree canopy volume, and fruit yield to fertilizer rate was described by a linear plateau model. The model predicted a fruit yield of 22.6 kg·tree-1 at the estimated critical rate of 48% of maximum. Fruit yield at 50% of maximum rate averaged 21.2 kg·tree. As fertilizer rate increased, total soluble solids (TSS) in juice and ratio (TSS:acid) decreased, but weight per fruit and TSS per tree increased. A fruit yield above 21 kg·tree-1 from 31-month-old trees was indicative of vigorous growth.

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Fertilizer Effects on Early Growth and Yield of `Hamlin' Orange Trees

HortScience ◽

10.21273/hortsci.28.2.111 ◽

1993 ◽

Vol 28 (2) ◽

pp. 111-114 ◽

Cited By ~ 21

Author(s):

Thomas A. Obreza ◽

Robert E. Rouse

Keyword(s):

Maximum Rate ◽

Fruit Yield ◽

Tree Canopy ◽

Water Soluble ◽

Soluble Solids ◽

Growth And Yield ◽

Fertilizer Rate ◽

Cross Sectional ◽

Solids Concentration ◽

Canopy Volume

The growth response of young `Hamlin' orange (Citrus sinensis L. Osbeck) on Carrizo citrange (C. sinensis × Poncirus trifoliatu L. Raf.) trees to N-P-K fertilizer rates under field conditions in southwestern Florida was studied to determine the minimum fertilizer required to bring trees into maximum early production. The highest 8N-1.8P-6.6K fertilizer rate was 2.72,5.45, and 8.17 kg/tree in 1989,1990, and 1991, respectively. Additional fertilizer treatments equaled 50%, 25%, or 13% of the maximum rate. Fertilizer sources contained either all water-soluble N (applied more frequently) or 40% to 50% controlled-release N (applied less frequently), and they did not affect fruit yield or quality. The response of trunk cross-sectional area, tree canopy volume, and fruit yield to fertilizer rate was described by a linear plateau model. The model predicted a fruit yield of 22.6 kg/tree at the estimated critical fertilizer rate of 48% of maximum. Fruit yield at the 50% maximum rate averaged 21.2 kg/tree. As fertilizer rate increased, total soluble solids concentration (TSS) in juice and the TSS: acid ratio decreased, but weight per fruit and TSS per tree increased. A fruit yield >21 kg/31-month-old tree indicated vigorous growth.

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Spray Volume, Canopy Density, and Other Factors Involved in Thinner Efficacy

HortScience ◽

10.21273/hortsci.33.3.553d ◽

1998 ◽

Vol 33 (3) ◽

pp. 553d-553

Author(s):

C.R. Unrath

Keyword(s):

Tree Height ◽

Tree Canopy ◽

Tree Size ◽

Water Volume ◽

Canopy Density ◽

The North ◽

Run Off ◽

Tree Canopies ◽

Average Water ◽

Water Volumes

Historically, most airblast chemical applications to apple orchards used a single “average” water volume, resulting in variability of coverage with tree size and also the greatest variable in chemical thinning. This coverage variability can be eliminated by properly quantifying the tree canopy, as tree row volume (TRV), and relating that volume to airblast water rate for adequate coverge. Maximum typical tree height, cross-row limb spread, and between-row spacing are used to quantify the TRV. Further refinement is achieved by adjusting the water volume for tree canopy density. The North Carolina TRV model allows a density adjustment from 0.7 gal/1000 ft3 of TRV for young, very open tree canopies to 1.0 gal/1000 ft3 of TRV for large, thick tree canopies to deliver a full dilute application for maximum water application (to the point of run-off). Most dilute pesticide applications use 70% of full dilute to approach the point of drip (pesticide dilute) to not waste chemicals and reduce non-target environmental exposure. From the “chemical load” (i.e., lb/acre) calculated for the pesticide dilute application, the proper chemical load for lower (concentrate) water volumes can be accurately determined. Another significant source of variability is thinner application response is spray distribution to various areas of the tree. This variability is related to tree configuration, light, levels, fruit set, and natural thinning vs. the need for chemical thinning. Required water delivery patterns are a function of tree size, form, spacing, and density, as well as sprayer design (no. of nozzles and fan size). The TRV model, density adjustments, and nozzle patterns to effectively hit the target for uniform crop load will be addressed.

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Effect of Four Training Systems on Growth and Productivity of `Cortland'/M.9 EMLA Apple Trees

HortScience ◽

10.21273/hortsci.33.3.451e ◽

1998 ◽

Vol 33 (3) ◽

pp. 451e-451

Author(s):

J.R. Schupp ◽

S.I. Koller

Keyword(s):

Fruit Size ◽

Vertical Axis ◽

Significant Loss ◽

Training Methods ◽

Cumulative Yield ◽

Or Efficiency ◽

Cross Sectional ◽

Tree Survival ◽

Canopy Volume ◽

Planting Distance

`Cortland'/M.9 EMLA trees were planted in 1991 at 1.8 ×4.2-m spacing. The trees were trained to one of four systems: 1) Vertical Axis; 2) Y trellis; 3) Solen; or 4) Palmette trellis. Tree survival was 86% for Palmette trees and approached 100% for the other three systems. Annual yield and cumulative yield per tree of Vertical Axis and Y trellis was twice that of Solen or Palmette. Tree vigor was sub-optimal relative to planting distance in this study. Trunk cross-sectional area of Vertical Axis trees was larger than that of trees trained to Solen or Palmette, while trees trained to Y trellis were intermediate in trunk growth. Canopy volumes of Vertical Axis and Y trellis trees were similar, and greater than that of Solen or Palmette trees. Fruit size on Solen and Palmette trees was larger than that of Y trellis trees in 1995 and 1996, while fruit size on Vertical Axis trees was intermediate. Cumulative yield per cubic meter of canopy volume was the same for all four systems, suggesting that differences in productivity among systems were attributable to the effects of tree training practices on tree size, not to differences among systems in precocity or efficiency. The low heading cut needed to establish the lowest tier of branches on the Palmette system reduced tree vigor and in some cases, resulted in mortality. The horizontal training of the primary branches of the Solen severely reduced tree vigor. In this study, where tree vigor was sub-optimal due to rootstock selection, the additional restrictions in tree growth resulting from restrictive training methods resulted in a significant loss in productivity.

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Phenotyping Architecture Traits of Tree Species Using Remote Sensing Techniques

Transactions of the ASABE ◽

10.13031/trans.14419 ◽

2021 ◽

Vol 64 (5) ◽

pp. 1611-1624

Author(s):

Worasit Sangjan ◽

Sindhuja Sankaran

Keyword(s):

Remote Sensing ◽

Structure From Motion ◽

Tree Species ◽

Tree Height ◽

Tree Canopy ◽

System Structure ◽

List Type ◽

Canopy Architecture ◽

Chemical Application ◽

Canopy Volume

HighlightsTree canopy architecture traits are associated with its productivity and management.Understanding these traits is important for both precision agriculture and phenomics applications.Remote sensing platforms (satellite, UAV, etc.) and multiple approaches (SfM, LiDAR) have been used to assess these traits.3D reconstruction of tree canopies allows the measurement of tree height, crown area, and canopy volume.Abstract. Tree canopy architecture is associated with light use efficiency and thus productivity. Given the modern training systems in orchard tree fruit systems, modification of tree architecture is becoming important for easier management of crops (e.g., pruning, thinning, chemical application, harvesting, etc.) while maintaining fruit quality and quantity. Similarly, in forest environments, architecture can influence the competitiveness and balance between tree species in the ecosystem. This article reviews the literature related to sensing approaches used for assessing architecture traits and the factors that influence such evaluation processes. Digital imagery integrated with structure from motion analysis and both terrestrial and aerial light detection and ranging (LiDAR) systems have been commonly used. In addition, satellite imagery and other techniques have been explored. Some of the major findings and some critical considerations for such measurement methods are summarized here. Keywords: Canopy volume, LiDAR system, Structure from motion, Tree height, UAV.

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Control of tree size and vigour in custard apple (Annona spp. hybrid) cv. African Pride in subtropical Australia

Australian Journal of Experimental Agriculture ◽

10.1071/ea01037 ◽

2002 ◽

Vol 42 (4) ◽

pp. 503 ◽

Cited By ~ 1

Author(s):

R. J. Nissen ◽

A. P. George

Keyword(s):

Growth Yield ◽

Fruit Weight ◽

Tree Canopy ◽

Tree Size ◽

Annona Squamosa ◽

Canopy Volume ◽

Custard Apple ◽

Root Restriction ◽

Subtropical Australia

Five methods of controlling tree size, viz. growth retardant (foliar-sprayed and trunk-injected paclobutrazol), root-restriction bags, cherimoya rootstock and sugar apple (Annona squamosa) interstock, were evaluated for their effects on growth, yield and fruit quality of custard apple (Annona spp. hybrid cv. African Pride) in subtropical Australia. Compared with trees on their own roots, sugar apple interstock was highly effective in dwarfing 'African Pride' trees, reducing tree canopy volume by 72-90%. Root-restriction bags (woven fibreglass) proved to be only partially effective in controlling tree size due to growth of major roots through the seams. Compared with trees on their own roots, cherimoya rootstock alone, and sugar apple interstock increased fruit weight per unit canopy volume by a maximum of 3- and 5-fold, respectively. Sugar apple interstock reduced the severity of fruit disorders 'woodiness' and 'brown pulp' by about 75 and 50%, respectively.

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(160) Seasonal Variations of Nutrient Status in Soil and Leaves, Soil Properties, and Tree Growth under Different Organic Apple Groundcover Management Production Systems

HortScience ◽

10.21273/hortsci.41.4.1032b ◽

2006 ◽

Vol 41 (4) ◽

pp. 1032B-1032

Author(s):

Hyun-Sug Choi ◽

Curt R. Rom ◽

Mengmeng Gu ◽

Jason McAfee

Keyword(s):

Soil Properties ◽

Seasonal Variations ◽

Soil Depth ◽

Wood Chip ◽

Tree Height ◽

Tree Canopy ◽

Water Infiltration ◽

Nutrient Concentrations ◽

Cross Sectional ◽

Weed Invasion

Seasonal variations of nutrient concentrations in soil and apple leaves, soil properties, weed density, and tree performance were observed for response to four groundcover managements systems: 1) mowed control; 2) plastic woven landscape fabric; 3) wood chip mulch; and 4) shredded commercial paper mulch. Soil sampled below the wood chip and shredded paper mulch treatments had higher NO3-N concentrations during the season. Soil below the shredded paper mulch had greater soil Ca, Na, and Zn than other treatments. Soil sampled below wood chip mulch had higher Mg and B. Leaf K was greater for trees grown with bark chip mulch than the other treatments. Overall, the seasonal patterns of N, P, and K decreased and had similar patterns as previously reported conventionally grown orchards. The leaf Ca and Mg increased during the season for all treatments. The concentration of other microelements had patterns similar among all treatments. Seasonal soil pH decreased during the season and was affected by treatments. During the season, water infiltration was faster into the soil covered with shredded paper mulch. The organic matter was greater in soil under the wood chip mulch at the 15-cm soil depth. Very little weed invasion occurred in the landscape fabric through August. Trees grown with shredded paper and wood chip mulch treatments had greater trunk cross-sectional area compared to trees grown under landscape fabric after 5 years; however, the latter treatment resulted in greater tree height, tree canopy spread, and fruit yield.

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Differential Watermelon Fruit Size Distribution in Response to Plastic Mulch and Spunbonded Polyester Rowcover

HortTechnology ◽

10.21273/horttech.18.1.45 ◽

2008 ◽

Vol 18 (1) ◽

pp. 45-52 ◽

Cited By ~ 7

Author(s):

Ramón A. Arancibia ◽

Carl E. Motsenbocker

Keyword(s):

Air Temperature ◽

Citrullus Lanatus ◽

Fruit Size ◽

Fruit Weight ◽

Growth And Yield ◽

Net Benefit ◽

Plastic Mulch ◽

Marketable Yield ◽

Ambient Temperatures ◽

Horticultural Crops

Plasticulture has been successfully used to enhance growth and yield of horticultural crops, and also for season extension in cooler climates. The effect of three plastic mulches (silver on black, photoselective thermal green, and black) in combination with spunbonded polyester rowcover (0.9 oz/yard2) on spring-planted watermelon (Citrullus lanatus) production was investigated. Two red-fleshed cultivars [Sangria (seeded) and Crimson Jewel (triploid)] were used. Plastic mulches increased early and total marketable yield in comparison with bare ground for both cultivars, but net benefit increased in ‘Crimson Jewel’ only. In contrast, yield and net benefit were the same among plastic mulches. Rowcover increased soil and air temperature, with the effect being greatest at lower ambient temperatures. During a near-freeze event, air temperature under the rowcover was about 7.2 °F higher than without a rowcover. Rowcover increased early and total marketable yield, but fruit weight decreased in both cultivars. Yield distribution into three fruit size categories was inconsistent between the cultivars. In ‘Sangria’, the large fruit category had the highest yield proportion for all treatments. In contrast, the highest yield proportion of ‘Crimson Jewel’, with exception of mulch without rowcover, corresponded to small fruit. Rowcover increased gross income at wholesale prices, but net benefit was not different from without rowcover. Protection of high-value plants, such as triploid watermelon, against light freezes, however, may still justify the use of rowcover in early plantings.

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Growth and yield of sweet cherry trees on different roostocks

International Journal of Horticultural Science ◽

10.31421/ijhs/5/3-4/55 ◽

1999 ◽

Vol 5 (3-4) ◽

Cited By ~ 2

Author(s):

K. Hrotkó ◽

L. Magyar ◽

G. Simon

Keyword(s):

Sweet Cherry ◽

Cross Sectional Area ◽

Tree Size ◽

Growth And Yield ◽

Sectional Area ◽

Cumulative Yield ◽

Cross Sectional ◽

Yield Efficiency ◽

Biennial Bearing ◽

Similar Tendency

The first nine years' results of sweet cherry rootstock trial from Hungary are presented with the aim to select efficient rootstocks for the local ecological conditions. The trials were established in 1989 with 'Van' and 'Germersdorfi óriás' cultivars on the following rootstocks: mahaleb Sainte Lucie 64, Colt, MxM 14, MxM 97. All the trees were headed at 80 cm and trained to a modified Brunner-spindle system. Tree size and yield was measured every year, and the cumulative yield efficiency was calculated. Based upon the results, mahaleb cherry SL 64 is a vigorous rootstock with good compatibility and productivity. In comparison to SL 64. the trunk cross-sectional area and canopy spread of the 'Van' trees decreased by 10-15% on rootstock Colt, while the trees of 'Germersdorfi orias' on Colt roostock grew even larger than on SL 64. Considerable 30-40 % reduction of tree size was achieved on trees grafted on M x M hybrids. Trees of `Germersdorfi óriás' showed a similar tendency without significant differences. The cumulative yield efficiency of `Van' trees after nine years was highest on rootstock MxM 14, followed by Sainte Lucie 64. Trees on Colt and MxM 97 rootstocks showed low productivity. `Germersdorfi óriás' produced the highest cumulative yield efficiency on SL 64, followed by MxM 14 and Colt and last MxM 97. Biennial bearing index of heavy cropping 'Van' trees was smaller than that of `Germersdorfi óriás'. The trees of 'Van' on MxM 97 showed higher biennial bearing index, while 'Germersdorfi orias' on different rootstocks showed similar tendency, but without significant differences. MxM 14 and MxM 97 rootstocks reduced the crotch angle of the shoots on both sweet cherry varieties which is disadvantegous to spindle training. Slight suckering (1-3/year) of the rootstocks Colt, MxM 14 and MxM 97 were observed during the first few years.

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068 EFFECT OF PRUNING SEVERITY ON APPLE TREE GROWTH, YIELD AND YIELD EFFICIENCY

HortScience ◽

10.21273/hortsci.29.5.437f ◽

1994 ◽

Vol 29 (5) ◽

pp. 437f-437

Author(s):

Terence L. Robinson

Keyword(s):

Conversion Efficiency ◽

Fruit Size ◽

Growth Yield ◽

Light Interception ◽

Cross Sectional ◽

Yield Efficiency ◽

Unit Increase ◽

Efficiency Conversion ◽

Highly Correlated ◽

Reduced Light

`Empire'/M.26 apple trees which were planted in 1978 and trained to a Y-trellis were pruned differentially from 1989-1993. Trees were dormant pruned by removing from 1-4 scaffold limbs. The annual increase in trunk cross-sectional area (TCA), and the number and length of shoots removed during summer pruning increased linearly as the severity of pruning increased. The number of shoots removed during summer pruning from the most severe pruning treatment was more than double that of the least severe treatment Cumulative fruit number and yield were reduced linearly with increasing severity of pruning while average fruit size was increased only slightly by severity of pruning. Light interception was reduced with increasing severity of pruning. Tree efficiency of converting light energy into fruit (g fruit/MJ PAR intercepted) was linearly reduced with increasing pruning severity. Most of the reduction in conversion efficiency appeared to be due to reduced partitioning of resources into fruit since partitioning index (g fruit/unit increase in TCA) was more highly correlated to pruning severity than to conversion efficiency. Conversion efficiency and partitioning index accounted for a greater portion of the yield variation than did light interception indicating that the influence of pruning on yield was more a function of changing internal physiology than reduced light interception.

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