Gregory S. McMaster

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Decision makers historically have indicated that inaccessibility of required geographic data and difficulties in synthesizing various recommendations are primary obstacles to spatial problem solving. Studies have shown that the quality of decisions (i.e., the ability to produce meaningful solutions) can be improved if these obstacles are lessened or removed(More)
Torrey pine exhibits a pattern of seed release intermediate between an open and closed-cone species. It was found that the cones open at maturity, but that seed fall from some cones continues for up to 13 years. Approximately 77% of the total seed crop was present in age classes one or more years past the time of seed maturity. Serotiny is thought to evolve(More)
McMaster, G.S., Morgan, J.A. and Wilhelm, W.W., 1992. Simulating winter wheat spike development and growth. Agric. For. Meteorol., 60: 193-220. Mechanistic crop simulation models can aid in integrating and directing research, and in improving farm management strategies. Information derived from recent research on spike development and growth of winter wheat(More)
Heading date in wheat (Triticum aestivum L.) and other small grain cereals is affected by the vernalization and photoperiod pathways. The reduced-height loci also have an effect on growth and development. Heading date, which occurs just prior to anthesis, was evaluated in a population of 299 hard winter wheat entries representative of the U.S. Great Plains(More)
Observations of a longer growing season through earlier plant growth in temperate to polar regions have been thought to be a response to climate warming. However, data from experimental warming studies indicate that many species that initiate leaf growth and flowering earlier also reach seed maturation and senesce earlier, shortening their active and(More)
Extensive research shows temperature to be the primary environmental factor controlling the phyllochron, or rate of leaf appearance, of wheat (Triticum aestivum L.). Experimental results suggest that soil temperature at crown depth, rather than air temperature above the canopy, would better predict wheat leaf appearance rates. To test this hypothesis, leaf(More)
McMaster, G.S., Klepper, B., Rickman, R.W., Wilhelm, W.W. and Willis, W.O., 1991. Simulation of shoot vegetative development and growth of unstressed winter wheat. Ecol. Modelling, 53: 189-204. Mechanistic crop simulation models can aid in directing research and improving farm management. Recent research on winter wheat (Triticum aestivum L.) canopy(More)
GPFARM is a decision support system (DSS) software package currently being developed by the USDA-ARS Great Plains Systems Research Unit. The primary goal of the Great Plains Framework for Agricultural Resource Management (GPFARM) DSS is to provide farmers and ranchers with a strategic tool to evaluate long-term effects of management and resource allocation(More)