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Open access

D. C. Ferree

Abstract

The impact of environmental factors on the photosynthetic potential of tree fruits is largely uncontrollable, but one can affect photo synthetic efficiency through the manipulation of various cultural practices. Application of pesticides and other chemicals; tree size and shape; mineral nutrition; and pest damage are all important factors and should be carefully considered in maximizing net photosynthesis (Pn) and ultimate tree performance.

Free access

Dalong Zhang, Yuping Liu, Yang Li, Lijie Qin, Jun Li, and Fei Xu

therefore effectively enhance plant photosynthesis and growth ( Lu et al., 2015 ; Zhang et al., 2015 , 2017 , 2018 ). It is generally considered that the movement of water through the soil–plant–atmosphere continuum is driven by a gradient in water

Open access

Haijie Dou, Genhua Niu, Mengmeng Gu, and Joseph Masabni

photosynthesis in lower plant canopy levels and subsequently increase plant yield at the whole plant canopy level ( Dou et al., 2019a ; Terashima et al., 2009 ; Wang and Folta, 2013 ). In addition, G wavelengths induce shade avoidance responses in plants, such

Open access

Hong Jiang, Zhiyuan Li, Xiumei Jiang, and Yong Qin

the photosynthetic characteristics, antioxidant system, and osmotic regulation of multiple vegetative organs of various crops have been studied. Salt stress can inhibit photosynthesis in plants (Han et al., 2014). High salt stress can reduce g S

Open access

A. M. Armitage, H. M. Vines, Tu Zeng-Ping, and C. C. Black

Abstract

The relationships of net photosynthesis (Pn) to soil water potential, leaf diffusive resistance, leaf water potential, and relative water content were studied with hybrid geranium (Pelargonium × hortorum Bailey cv Sprinter Scarlet) grown under conditions of greenhouse pot culture. Net photosynthesis went through 4 stages according to the effects of water stress on the plants. As water stress increased, Pn went from a steady-state maxiumum rate to slow decline, to rapid decline, to total inhibition. During rapid Pn decline, soil water potential rapidly decreased from −4 bars to −14 bars, and leaf diffusive resistance increased from 4 s cm−1 to 80s cm−1. Leaf water potential was −7 bars, and relative leaf water content was 81–87%. Leaf water potential appeared to be the best indicator of imminent Pn decline. After rewatering water-stressed plants, 3 days were required to elevate Pn to a steady-state maximum which was only 90% of initial steady-state Pn.

Open access

H. T. Phung and E. B. Knipling

Abstract

Photosynthesis and transpiration rates of seedlings of 4 citrus rootstocks under flooded conditions were measured over a 10-day period. For all rootstocks photosynthesis and transpiration decreased, but photosynthesis decreased relatively less than transpiration. Stomatal closure is inferred to account in part for the reductions observed.

Flooding did not increase ethanol concentration in either tops or roots, suggesting that ethanol is not an end-product of. anaerobic respiration in citrus seedlings. Only in the neutral soil was rough lemon (Citrus limon L. Burm. f.) found to be more tolerant to short-term flooding than ‘Cleopatra’ mandarin (Citrus reticulata Blanco) and trifoliate orange (Poncirus trifoliata L. Raf.). Tolerance to flood injury was greater at a soil pH of 7 than 4.5.

Free access

Rebecca M. Harbut, J. Alan Sullivan, John T.A. Proctor, and Harry J. Swartz

photosynthesis ( Zelitch, 1982 ). The increases in yield over the last century have been largely the result of increases in harvest index and light interception; however, the role that photosynthesis has played is not completely understood ( Richards, 2000 ). In

Free access

Wenjie Ma, Wen Liang, and Bing Zhao

environment) ( Fanourakis et al., 2016 ). Research has shown that VPD not only has a direct effect on stomatal conductance ( g s ), photosynthesis, and water transport ( Sinclair et al., 2007 ) but also affects plant temperature via transpiration. Greater VPD

Open access

Alan N. Lakso and Earl J. Seeley

Abstract

Although upper limitations on photosynthesis by apple trees are imposed by the structure and biochemistry of the leaf, an apple tree has a considerable potential for the fixation of carbon. Within these limits it is important to determine factors that prevent attainment of the tree’s full biological productivity. This review describes our present knowledge of some of these factors, both environmental and internal, that determine the actual biological productivity of the apple tree.

Free access

Dawei Shi, Xiaodong Wei, Guoxiang Chen, and Yanli Xu

Leaf senescence is characterized by programmed degradation of cellular constituents such as proteins, nucleic acids, and lipids, together with organelles and structures of leaf cell, resulting in a significant photosynthetic decline. Photosynthesis