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Royal D. Heins

Environmental control computers allow regulation of greenhouse environments based on some model driven factor or factors other than fixed heating and cooling setpoints. A quantitative understanding of how environmental factors influence rate of plant development, flower initiation, and plant morphology is necessary to develop models for environmental control. The major limitation to the use of models for greenhouse climate and crop control is the lack of quantitative models. Examples of model development for environmental control will be discussed.

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Lee Ann Moccaldi and Erik S. Runkle

were grown at a mean daily temperature of 14 to 27 °C with a mean DLI of 5 to 25 mol·m −2 ·d −1 , which represent the range of conditions for most commercial greenhouse companies that produce ornamental annuals. Plant models were then developed to

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Ralf Uptmoor, Mildred Osei-Kwarteng, Susanne Gürtler, and Hartmut Stützel

The combined application of molecular markers and ecophysiological models can help to speed up the development of improved cultivars and enable the dissection of complex agronomic traits into the underlying physiological factors (e.g., for an

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Arthur Villordon, Julio Solis, Don LaBonte, and Christopher Clark

Singh et al. (1992) predicted that computer-based crop growth models were going to increase for root crops, including sweetpotatoes. To our knowledge, only two process-based models have been published thus far ( Mithra and Somasundaram, 2008

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Dewayne L. Ingram, Charles R. Hall, and Joshua Knight

specific production protocols to make informed decisions ( Ingram and Hall, 2015b ) regarding input use and cultural practice selection. This study should help fill that void. Materials and Methods Two systems (entitled System A and System B) were modeled

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Steven E. Woerner and Douglas A. Hopper

A computer simulation model was developed to be used in evaluating irrigation scheduling techniques and assisting irrigation scheduling decisions under greenhouse conditions in Colorado. The model simulates variable greenhouse conditions and shows how each of four irrigation scheduling techniques responds to these conditions. Reports from the model detail numbers of irrigation events, sensitivities to parameters, and forecasts water usage. The model was also used to determine appropriate accumulation triggers for Colorado conditions.

Four techniques evaluated here include: time clock control; accumulated radiation; accumulated vapor pressure deficit; combination method (radiation and vapor pressure deficit). The model has shown the combination method to be the most sensitive to changes in environmental conditions, while the time clock method proved to be least sensitive (and most wasteful of water).

The model may evaluate additional irrigation scheduling techniques by including additional parameters in the model, and may readily be adapted to different climatic regions.

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Girija Page, Terry Kelly, Maria Minor, and Ewen Cameron

. 1. Carbon cycle of an orchard system for carbon footprinting. Application to organic orchard systems. The described approach to carbon footprinting was applied to three model organic fruit production systems: kiwifruit (500 vines/ha); semi

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Priyanka Sharad Mahangade, Indra Mani, Randolph Beaudry, Norbert Müller, and Sangeeta Chopra

these and other structures or chambers having fluctuating conditions, it is difficult to evaluate and compare performance and efficacy for predicting the storage of perishables. We propose that a “model” plant material might prove an efficacious way to

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Richard C. Beeson Jr

conserve water. Attempts to develop such an irrigation model for container-grown woody shrubs have been limited. Knox (1989) reported relatively high correlations between pan evaporation, a growth index, and ET A for five woody ornamentals during a

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Thomas M. Kon, James R. Schupp, Keith S. Yoder, Leon D. Combs, and Melanie A. Schupp

( Byers, 2003 ). An inherent challenge with blossom thinning is the short period of time that growers have to apply treatments over large acreage ( Moran and Southwick, 2000 ). Models have been developed to estimate the rate of pollen tube growth in apple