Iron Sulfate and Phosphorous Acid Affect Turfgrass Surface pH and Microdochium Patch Severity on Annual Bluegrass.

Microdochium patch is a turfgrass disease caused by the fungal pathogen Microdochium nivale. Iron sulfate heptahydrate (FeSO4•7H2O) and phosphorous acid (H3PO3) applications have previously been shown to suppress Microdochium patch on annual bluegrass putting greens when applied alone, although either disease suppression was inadequate or turfgrass quality was reduced from the applications. A field experiment was conducted in Corvallis, Oregon, U.S.A., to evaluate the combined effects of FeSO4•7H2O and H3PO3 on Microdochium patch suppression and annual bluegrass quality. The results of this work suggest that the addition of 3.7 kg H3PO3 ha-1 with 24 or 49 kg FeSO4•7H2O ha-1 applied every 2 weeks improved the suppression of Microdochium patch without substantially compromising turf quality, which occurred when 98 kg FeSO4•7H2O ha-1 was applied with or without H3PO3. Spray suspensions reduced the pH of the water carrier, therefore two additional growth chamber experiments were conducted to better understand the effects of these treatments on leaf surface pH and Microdochium patch suppression. On the application date in the first growth chamber experiment, at least a 19% leaf surface pH reduction was observed compared with the well water control when FeSO4•7H2O was applied alone. When 3.7 kg H3PO3 ha-1 was combined with FeSO4•7H2O, regardless of the rate, the leaf surface pH was reduced by at least 34%. The second growth chamber experiment determined that sulfuric acid (H2SO4) at a 0.5% spray solution rate was always in the group that produced the lowest annual bluegrass leaf surface pH, but did not suppress Microdochium patch. Together, these results suggest that while treatments decrease leaf surface pH, this decrease in pH is not responsible for the suppression of Microdochium patch.

Social cognitive predictors of physical activity in relapsing-remitting multiple sclerosis.

BACKGROUND: Persons with relapsing-remitting multiple sclerosis (RRMS) are often sedentary, despite the benefits of the regular physical activity. This has motivated the search for variables that act as determinants of physical activity. Such variables are derived from theory and presumably represent targets of behavioral interventions for increasing physical activity. PURPOSE: This prospective, observational study examined variables from social cognitive theory as determinants of physical activity 6 weeks later in persons with RRMS. METHODS: Persons (N = 68) with RRMS initially completed a questionnaire battery that included measures of self-efficacy, physical, social, and self-evaluative outcome expectations, functional limitations as an impediment, social support as a facilitator, and goal setting for physical activity. The participants wore an accelerometer and completed a self-reported physical activity measure 6 weeks later. Data were analyzed using path analysis in Mplus 3.0. RESULTS: Self-efficacy (path coefficient = 0.19, p < 0.05), functional limitations (path coefficient = -0.33, p < 0.0001), and goal setting (path coefficient = 0.26, p < 0.01) had statistically significant direct effects on physical activity. Self-efficacy further had a statistically significant indirect effect on physical activity by way of functional limitations (path coefficient = 0.12, p < 0.05), but not by goal setting (path coefficient = 0.02, p = 0.66). This model explained 28 % of the variance in physical activity. CONCLUSIONS: This prospective study suggests that self-efficacy, functional limitations, and goal setting might represent modifiable targets of behavioral interventions for increasing physical activity among persons with RRMS.