Mechanical Harvesting Has Little Effect on Water Status and Leaf Gas Exchange in Citrus Trees

@article{Li2005MechanicalHH,
  title={Mechanical Harvesting Has Little Effect on Water Status and Leaf Gas Exchange in Citrus Trees},
  author={Kuo-Tan Li and James P. Syvertsen},
  journal={Journal of the American Society for Horticultural Science},
  year={2005},
  volume={130},
  pages={661-666}
}
  • Kuo-Tan Li, J. Syvertsen
  • Published 1 September 2005
  • Biology
  • Journal of the American Society for Horticultural Science
Mechanical harvesting of citrus trees can cause physical injuries, such as shedding of leaves, exposing roots, and scuffi ng bark. Although mechanical harvesting usually has not reduced yield, physiological consequences to the tree from these visible injuries have not been investigated. We hypothesized that physical injuries to tree canopies and root systems from a properly operated trunk shaker would not cause short-term physiological effects. Tree water status and leaf gas exchange of mature… 

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References

SHOWING 1-10 OF 27 REFERENCES
Effects of crop load on fruiting and gas-exchange characteristics of 'Braeburn'/M.26 apple trees at full canopy.
TLDR
From midseason until fruit harvest, leaf photosynthesis decreased significantly on lighter cropping trees and similarly, a positive linear trend was found between whole-canopy gas exchange per unit area of leaf and crop load, providing some explanation for the increased down-regulation of photosynthesis on trees with lower crop loads.
Mechanical Harvesting of Peaches—Limited Potential
This study evaluated the total and marketable yield of three peach cultivars (Prunus persica (L.) Batsch. 'Autumnglo', 'Harvester', and 'Redhaven') when mechanical pruning and harvesting systems were
Fruit load and canopy shading affect leaf characteristics and net gas exchange of 'Spring' navel orange trees.
TLDR
Overall, the presence of a normal fruit crop resulted in lower foliar carbohydrate concentrations and higher Ac compared with defruited trees, except on warm days when Ac was reduced by high leaf temperatures.
Effect of delayed fruit harvest on photosynthesis, transpiration and nutrient remobilization of apple leaves
TLDR
Fruit harvest accelerated leaf senescence, indicated by chlorophyll breakdown and remobilization of nutrients in both spur and long shoot Leaves, and, additionally, by commencing anthocyanin synthesis in long shoot leaves.
Partial shoot removal increases net CO(2) assimilation and alters water relations of Citrus seedlings.
TLDR
Increased carbon demand for shoot regrowth increased photosynthetic capacity and was more important than stomatal responses in determining A after partial shoot loss in Citrus spp.
Antitranspirant and root and canopy pruning effects of mechanically transplanted eight-year-old Murcott citrus trees
Two groups of 8-year-old ‘Murcott’ [Citrus reticulata Blanco × C. sinensis (L.) Osbeck hybrid?] trees on rough lemon (C. jambhiri Lush.) rootstock were transplanted with a Vermeer tree digger in
A Review of Citrus Harvesting in Florida
The removal of Florida citrus from the tree for harvesting is still done by handpickers on ladders and requires a work force of 20,000 to 35,000 persons. Moving fruit from the grove and subsequent
Salinity Effects of Leaf Water Relations and Gas Exchange of 'Valencia' Orange, Citrus sinensis (L.) Osbeck, on Rootstocks With Different Salt Exclusion Characteristics
TLDR
The response of A to pi was affected by salinity in such a way that impact of salt on CO2 assimilation was expressed to a greater degree at high pI, and photosynthetic sensitivity to increased leaf chloride also appeared to diminish on Trifoliata.
Relative effects of growth retardant (Paclobutrazol) and water stress on tree growth and photosynthesis in ponkan (Citrus reticulata Blanco)
TLDR
Application of paclobutrazol ameliorated photosynthetic reductions associated with water stress, by maintaining higher photosynthesis and transpiration rates during water stress and ensuring quicker recovery after re-watering.
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