Researchers are increasingly able to capture spatially referenced data on both a response and a covariate more frequently and in more detail. A combination of geostatisical models and analysis of covariance methods may be used to analyze such data. However, very basic questions regarding the...

We estimated the economic benefits resulting from controlling soybean aphid infestation by using a multi-regional competitive dynamic equilibrium model. Results indicate that the reduction of soybean production resulting from a soybean aphid infestation is largely absorbed by reducing soybean...

In the southern Great Plains of the United States, winter wheat is a dual purpose crop that produces forage for livestock grazing in the fall and winter, and a grain crop in the spring. Seasonal and interannual climate variations are pronounced and make it difficult to anticipate forage...

Multivariate statistical analyses were employed in data reduction of six fruit qualitative traits, along with economic value and a final score of fruit quality, scored on fruits of 203 date palm varieties grown in 19 ecogeographical regions in six countries of the Arabian Peninsula. Fruit color...

Conventional soybean [Glycine max (L.) Merr.] production in the midsouthern USA has involved planting Maturity Group (MG) V and later cultivars in May and later months in a seedbed that has been shallow-tilled in the fall or spring just before planting. Moisture deficits that frequently occur...

Dietary surveys are important for understanding food consumption patterns in national studies, clinical research, and patient counseling. Portion size estimation aids usually increase accuracy of consumers' reports of the amount of food they ate in dietary surveys. However, wedge-shaped foods...

Citrus canker assessment data were used to investigate effects of using the Horsfall-Barratt (H-B) scale to estimate disease compared to direct estimation to the nearest percent. Twenty-eight raters assessed each of two-hundred infected leaves (0-38% true diseased area). The data were converted...

Natural resources models serve as important tools to support decision making by predicting environmental indicators. All model predictions have uncertainty associated with them. Model predictive uncertainty, often expressed as the confidence interval around a model prediction value, may serve as...

The impact of livestock grazing on water quality, especially erosion and sedimentation, is an important concern in the southwestern United States. In response to Federal and State regulations, Best Management Practices (BMPs) for rangeland management are being developed and implemented in many...

For most irrigation systems, the most practical method for determining the global distribution uniformity (i.e., that experienced by the entire crop) is to measure the uniformity resulting from several components and combine them statistically. In this paper, procedures and equations are...