New alfalfa varieties are constantly being introduced into the marketplace. The number of varieties available for low-elevation desert areas in Arizona in the non-dormant class is over50. New varieties are introduced each year and unbiased yield comparisons are helpful to the grower to base the decision of whether or not to sow a new variety. The study reported here is part of the on-going effort to evaluate alfalfa variety performance in Arizona. A summary of alfalfa variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1267.pdf.

Invinsa blocks ethylene perception by plants and can reduce the negative effects of water stress on crop growth. The objective of this study is to measure the effect on corn growth and yield of Invinsa application at incipient water stress. A study was conducted at the University of Arizona Maricopa Agricultural Center where Invinsa was applied on 15 May in blocks with adequate or deficit irrigation. The deficit irrigation block received no irrigation water for 7 days past incipient stress beginning on 15 May, but otherwise received adequate water during the other parts of the season. Invinsa had little or no effect on crop growth measured at five different dates during the growing season. Invinsa had no effect on grain yield, grain moisture content, harvest index, ear number, kernels per ear, kernel weight, and silking date. We were not able to measure an effect of Invinsa on photosynthetic rate, conductance to water, intercellular CO2 concentration, vapor pressure deficit, or leaf temperature. However, Invinsa increased daily water use at various time periods, particularly in the adequate irrigation regime. The lack of a response this year to Invinsa, other than water use, is similar to the results from last year where no consistent response was measured. Invinsa has increased corn yield in other regions, and heat and/or water stress at the Maricopa may mask the effects of Invinsa or render it ineffective.

New alfalfa varieties are constantly being introduced into the marketplace. The number of varieties available for low-elevation desert areas in Arizona in the non-dormant class is aver50. New varieties are introduced each year and unbiased yield comparisons are helpful to the grower to base the decision of whether or not to sow a new variety. The study reported here is part of the ongoing effort to evaluate alfalfa variety performance in Arizona. A summary of alfalfa variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1267.pdf.

Small grain varieties are evaluated each year by University of Arizona personnel. The purpose of these tests is to characterize varieties in terms of yield and other attributes. Variety performance varies greatly from year to year and several site-years are necessary to adequately characterize the yield potential of a variety. A summary of small grain variety trials conducted by the University of Arizona can be found online at http://ag.arizona.edu/pubs/crops/az1265.pdf.

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Over the last twenty years or so, dairying has become the largest agricultural enterprise in Quebec. It has also become the most profitable, supplanting other less profitable farm enterprises. Dairying in Quebec has grown to the point where Quebec is now Canada's leading dairy province. [...]

The successful application of crop processing on pull-type forage harvesters requires engineering analysis and experimentation in areas such as roll design, particle aerodynamic, vibration, power measurement and crop physical characterization. The first step of this research project was to design, build and evaluate two processing rolls integrated in an experimental pull-type forage harvester. With a 12.7 mm theoretical length of cut setting, the processing rolls were used to treat alfalfa at a 1 mm clearance between the rolls. Samples analyzed at an animal research centre showed that processing increased the effective ruminal degradability of corn by 3% but did not improve the degradability of alfalfa. / The presence of processing rolls in the forage harvester increased friction. The air inlet area had to be increased to improve particle flow and obtain maximum air outlet speed. The presence of crop processing rolls required an increase in blower speed of 10 to 20% to maintain the throwing capacity. / Critical speeds were analyzed by the Transfer Matrix Component Mode Syntheses (TMCMS) method and three classical approaches using analytical models to predict deflections in the shaft. Experiments showed that the TMCMS method was very reliable and predicted the critical speed with an error of about 4% compared to 8% or higher for classical methods. Modal analysis also proved to be a simple and practical way to measure critical speed. / A laboratory setup was built to investigate various mechanical adjustments: roll clearances of 4 and 6 mm for corn, and 1 and 3 mm for grass; eight peripheral speed ratios between 1.08 and 1.93; two levels of throughput (9 and 18 t fresh crop/h). Optimal adjustment will ultimately depend on animal response to various levels of crop breakage. / A hydrodynamic model of chopped forage processed between rolls was developed to determine crop properties using an experimental database and subsequently predict the power requirement as a function of the configuration. Forage specific area was estimated using an experimental micro-screening method. A program was developed to calculate mechanical stresses within each roll of the crop processor as a function of working conditions and steel properties. (Abstract shortened by UMI.)

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