Pathogen exposure to sublethal doses of fungicides may result in mutations that may represent an important and largely overlooked mechanism of introducing new genetic variation into strictly clonal populations, including acquisition of fungicide resistance. We tested this hypothesis using the clonal plant pathogen, Sclerotinia sclerotiorum. Nine susceptible isolates were exposed independently t...

Strobilurin fungicides produce intensified greening and delayed senescence in plants, and have been claimed to enhance yields of field crops in the absence of disease. To help evaluate this claim, available publicly sponsored tests of fungicides on soft red winter wheat in Virginia and North Carolina (n = 42) were analyzed for the period 1994 to 2010. All tests were replicated and had a randomi...

Many studies exist about the selection phase of fungicide resistance evolution, where a resistant strain is present in a pathogen population and is differentially selected for by the application of fungicides. The emergence phase of the evolution of fungicide resistance--where the resistant strain is not present in the population and has to arise through mutation and subsequently invade the pop...

In this research, the covariance estimates were used to estimate population mean in stratified random sampling and combined regression estimates. compared by employing robust variance-covariance matrices with traditional when estimating parameter, through two efficiency criteria (RE) squared error (MSE). We found that significantly improved quality of reducing effect outliers using (MCD, MVE) p...

One robust result from many small-scale experiments has been that plant community productivity often increases with increasing plant diversity. Most frequently, resource-based or competitive interactions are thought to drive this positive diversity-productivity relationship. Here, we ask whether suppression of plant productivity by soil fungal pathogens might also drive a positive diversity-pro...

Fungicide mixtures produced by the agrochemical industry often contain low-risk fungicides, to which fungal pathogens are fully sensitive, together with high-risk fungicides known to be prone to fungicide resistance. Can these mixtures provide adequate disease control while minimizing the risk for the development of resistance? We present a population dynamics model to address this question. We...

In three field trials fungicides used for stem rust (Puccinia graminis) control were evaluated to assess the effect on levels of blind seed disease, seed germination and endophyte (Neotyphodium lolii) transmission. Blind seed disease infection was reduced from 24% to 5% in one of the three trials undertaken and germination was increased by between 17 and 23% in two trials. There was a negative ...

It is a well-established result that the marginal probability of a social tie between two persons declines with geographical distance for a wide range of social relations (see, e.g., Bossard, 1932; Zipf, 1949; Festinger et al., 1950; Hägerstrand, 1967; Freeman et al., 1988; Latané et al., 1995; McPherson et al., 2001). While often regarded as a mere curiosity, others have argued that this relat...

Abstract When monitoring industrial processes, a Statistical Process Control tool, such as multivariate Hotelling T 2 chart is frequently used to evaluate multiple quality characteristics. However, research into the use of charts for survey fieldwork–essentially production process in which data sets collected by means interviews are produced–has been scant date. In this study, using from eighth...

Fungal Lipids, Ergosterol, Inhibition, Etaconazole, Fungicide The triazole fungicide etaconazole (C G A 64 251) interferes with the ergosterol biosynthesis in Ustilago maydis by inhibiting the C-14 demethylation o f the sterol nucleus. During the late log growth phase o f U. maydis a novel endogenous sterol metabolite (14x-methyl-ergosta-8,24(28)dien-3/?,6a-diol) was discovered and analyzed, wh...