The increased interest in the variability of soil properties is responsible for recent observations that soil variables are not normally distributed but are more closely approximated by the two-parameter lognormal frequency distribution. Statistical methods commonly applied in the estimation of...

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...

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...

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...

Binomial sampling based on the proportion of samples infested was investigated for estimating mean densities of citrus rust mite, Phyllocoptruta oleivora (Ashmead), and Aculops pelekassi (Keifer) (Acari: Eriophyidae), on oranges, Citrus sinensis (L.) Osbeck. Data for the investigation were...

While no-till (NT) cropping systems can provide conservation benefits in the northern Corn Belt, adoption has been low due to concerns about potential yield reductions and economic risk. Strip-tillage (ST) systems have been proposed as an alternative that may provide many of the conservation...

Regression analysis of repeated-measures data from plots in large experiments is both labor intensive and time consuming. When duration estimates characterizing each individual repeated-measures series are of interest, numerical integrations are possible alternatives. This note evaluates a...

Recent soil and crop management technologies have potential for mitigating greenhouse gas emissions; however, these management strategies must be profitable if they are to be adopted by producers. The economic feasibility of reducing net greenhouse gas emissions in irrigated cropping systems was...

Soybean [Glycine max (L.) Merr.] was domesticated in China but has a long history of cultivation on the Korean peninsula and in Japan. All three areas are considered important sources of soybean germplasm. The objectives of this study were to evaluate the genetic variation in soybean within and...

From 1997 to 1999, Schizaphis graminum (Rondani), intensity (number per tiller) was estimated on 115 occasions from hard red winter wheat fields located throughout the major wheat growing regions of Oklahoma. A total of 32 and 83 fields was sampled during the fall and spring, respectively. The...