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Chenping Xu and Beiquan Mou

chitosan as a soil amendment might also result from its direct effect on plant nutrient status and metabolism, and photosynthesis. Soil-applied chitosan increased the content of nitrogen, phosphorus, potassium, total sugars, and soluble proteins as well as

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S. Kumudini

Cranberry [Vaccinium macrocarpon (Ait.)] yield has been associated with photosynthate supply. However, the impact of temperature and radiation on photosynthesis of the cranberry plant is not well understood. The objective of this experiment was to characterize the photosynthetic response to radiation and temperature in order to develop a model for estimation of cranberry photosynthetic rates. Two cranberry cultivars, `Stevens' and `Ben Lear', were tested for photosynthetic response at air temperatures ranging from 15 to 35 °C and radiation intensities from 200 to 1200 μmol·m-2·s-1. Depending on temperature, maximum photosynthesis (Pmax) was ≈10 or 12 μmol CO2/m2/s (net photosynthesis) and the saturating radiation level was estimated to be 600 to 800 μmol·m-2·s-1. Cranberry quantum yield was estimated as 0.03 mol CO2/mol photon. Both models; Blackman and the nonrectangular hyperbola with a Θ (angle of curvature) of 0.99 were a good fit for measured photosynthetic rates under controlled environment conditions. The disparity between modeled predicted values, and observed values in the field around midday, indicates a reduction in potential photosynthetic rates in a diurnal cycle that is consistent with the phenomenon of midday depression.

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Krishna Nemali and Marc W. van Iersel

declines rapidly with small changes in substrate water content ( da Silva et al., 1993 ), making it more difficult for plants to extract water when Θ is low in the substrate. Photosynthesis is central to crop growth and highly sensitive to drought stress

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Richard J. Heerema, Dawn VanLeeuwen, Rolston St. Hilaire, Vince P. Gutschick, and Bethany Cook

. Leaf gas exchange was measured on 2 Oct. 2009, 1 Oct. 2010, and 5 Nov. 2010. Because ‘Western’ kernel fill continues through October in New Mexico, the early November photosynthesis measurement date was included in 2010 to ensure that we captured the

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Dario Mantovani, Adolfo Rosati, and Domenico Perrone

chamber. Because it is assumed that only one side of the cladode is sunlit, the photosynthesis values referred to half the lateral area, in accordance with the methodology used for Asparagus officinalis ( Guo et al., 2002 ). Spear photosynthesis was

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Sara Andrea Moran-Duran, Robert Paul Flynn, Richard Heerema, and Dawn VanLeeuwen

data and SPAD readings were recorded, and the leaflet had to be located in the middle canopy of the tree. The same leaflet was used for both P n and SPAD. Leaf P n was measured using the LI-COR 6400XT portable photosynthesis system (LI-COR Inc

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Md. Jahedur Rahman, Haruhisa Inden, and Masaaki Kirimura

( Connor et al., 1993 ), sink assimilate demand ( Frageria, 1992 ), and availability of water as well as light and nutrients. Photosynthesis is also affected by different stress factors ( Taiz and Zeiger, 2006 ). The capacity of the plant’s photosynthetic

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Ozlem Altuntas, H. Yildiz Dasgan, and Yelderem Akhoundnejad

., 2016 ). Silicon is also considered to be a beneficial element for plants ( Epstein and Bloom, 2005 ), and some argue that it is essential ( Ma, 2004 ). Whether essential or not, Si enhances water and solute transport, improves photosynthesis rates, and

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D. Joseph Eakes, Robert D. Wright, and John R. Seiler

Abbreviations: CA, leaf chamber CO 2 concentration; CI, leaf internal CO 2 concentration; E, transpiration; g L , leaf conductance; MSC, moisture stress conditioning; Pn, net photosynthesis; r m , mesophyll resistance to CO 2 ; SI, stomatal

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Koichi Nomura, Masahiko Saito, Ikunao Tada, Tadashige Iwao, Tomihiro Yamazaki, Nobuyuki Kira, Yasuyo Nishimura, Makito Mori, Esteban Baeza, and Masaharu Kitano

In modern horticultural crop production, wherever root-zone environments are optimally managed, canopy photosynthesis becomes the primary determinant of crop growth and yield, as suggested by numerous CO 2 enrichment experiments ( Ainsworth and