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Xiaojie Zhao, Guihong Bi, Richard L. Harkess, Jac J. Varco, and Eugene K. Blythe

( Lockatell and Spoon, 2011 ). However, limited information is available regarding how N rate affects spring N uptake and use efficiency in TB iris. Nitrogen plays an important role in plant growth and development. Insufficient N supply restricts plant growth

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Hye-Ji Kim and Xinxin Li

obtained from global phosphate rock reserves, and is a nonrenewable resource that could be depleted in 50–100 years ( Marschner, 2012 ), and therefore, increasing the efficiency with which these reserves are used to produce crops is vital to maintain or

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Krishna S. Nemali and Marc W van Iersel

.S. Department of Agriculture, 2006 ); however, little work has been done to optimize water use in their production. Two factors combine to determine water use in bedding plant production; i.e., irrigation management practices that determine irrigation efficiency

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Lois C. Braun, Jeffrey H. Gillman, and Michael P. Russelle

. However, the ecological benefits of growing hazelnuts could be undermined if inappropriate nitrogen (N) fertilization practices are used, leading to N pollution. According to Weinbaum et al. (1992) , orchard crops have among the lowest N uptake efficiency

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Youssef Rouphael, Giampaolo Raimondi, Rosanna Caputo, and Stefania De Pascale

resource use efficiency. Materials and Methods Plant material, growth conditions, and experimental design. The experiment was conducted from May to Oct. 2008 at the experimental station of the University of Naples Federico II located in Pontecagnano

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Robert C. Ebel, Jacqueline K. Burns, Kelly T. Morgan, and Fritz Roka

; Yuan and Burns, 2004 ). This study was conducted to determine the relationship of CMNP concentration and cycling frequency of canopy shakers on harvest efficiency of ‘Hamlin’ and ‘Valencia’ sweet orange. The study was conducted on multiple dates for

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Chenping Xu and Beiquan Mou

; Konica Minolta Sensing, Tokyo, Japan). Leaf maximum photochemical efficiency (F v /F m ), photochemical yield [Y(II)] and electron transport rate (ETR) were measured with a fluorometer (MINI-PAM-II; Heinz Walz, Effeltrich, Germany) on the four largest

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Furn-Wei Lin, Kuan-Hung Lin, Chun-Wei Wu, Yu-Sen Chang, Kuan-Hung Lin, and Chun-Wei Wu

irrigation (RDI). Table 2. Effects of different concentrations of betaine on the gas exchange parameters and water use efficiency (WUE i , WUE yield , WUE biomass ) of lettuce under full irrigation (FI) and regulated deficit irrigation (RDI). Fig. 1. Effects

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Carol A. Miles

Improving sweet corn fertilizer-N efficiency promotes a more vigorous and healthy crop, rewards the grower with greater profits, and protects our water resources from nitrate-N pollution. Two areas of research that have the potential to improve the efficiency of fertilizer-N applications are the Minolta SPAD 502 chlorophyll meter and the presidedress soil N test. The SP meter is a rapid and nondestructive technique for assessing sweet corn leaf levels, and SP readings have been correlated to leaf N concentration. A presidedress soil N test measures the amount of soil N that will be available to the plant during the remainder of the growing season. SP meter readings combined with presidedress soil N analyses may be used to determine crop N needs and fertilizer-N sidedress application rates. Basing fertilizer-N sidedress application rates on actual crop N needs will reduce excess fertilizer-N applications and the resulting leaching of nitrates.

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Marc W. van Iersel, Matthew Chappell, and John D. Lea-Cox

. Sensor networks and water use models have been suggested as ways to improve irrigation efficiency and reduce water use in ornamental horticulture ( Lea-Cox, 2012 ; Million et al., 2010 ). Using sensors to collect quantitative information about crop water