Preliminary Evaluation of a Dodder Anthracnose Fungus from China as a Mycoherbicide for Dodder Control in the US

Dodder (Cuscuta spp.) is a noxious, parasitic, annual weed throughout most of the United States. A fungus used to control it in China was imported under permit for studies with U.S. dodder species in containment. The fungus, Colletotrichum gloeosporioides, sporulated on liquid and solid media at room temperature. Conidia from 7-12 day old cultures were diluted to 3.5 to 7 X 16⁶ spores ml^-1 for host range inoculations. Germination on water agar at 24 hrs was higher at 28 than 30 or 24 C. Inoculated plants were exposed to dew periods of 12-1 4 hrs at 24 or 28 C, then transferred to growth chambers with 1 2-hr photoperiods at constant temperatures of 24, 28, and 32C. Dodder species were severely diseased but rarely killed. Symptoms were most severe on native collections of Cuscuta campestris after 4 to 5 days incubation when this species on periwinkle seedlings was inoculated with 3.5 to 7 X 10⁵ spores ml^-1 . Cuscuta cuspidata, C. pentagona, and C. campestris from a California seedlot were also tested under optimum conditions for disease. The C. campestris from California was the most susceptible. Inoculation of 16 species in eight plant families revealed no other host except sweet potato which developed a necrotic fleck. This research indicates a need for strain improvement prior to field tests

MARKETING AND CROP INSURANCE COMBINED TO MANAGE RISK ON A CASS COUNTY REPRESENTATIVE FARM

This study analyzed the effects that the use of crop insurance products and marketing alternatives had on the gross revenue per acre for an individual farm in Cass County. Crop insurance products and marketing strategies were analyzed individually to determine if they were effective in minimizing down side risk, and combined to determine if integration created synergies. A whole farm scenario analysis was run that included integrated strategies that implemented the same insurance coverage and marketing alternatives for each crop. Several general conclusions can be drawn for situations similar to the representative farm. When analyzed at the individual crop level, the use of crop insurance at the 65 percent level minimizes down side risk in wheat and corn, but not significantly in soybeans. Marketing alternatives generally increase the up side potential of gross revenue per acre, while doing little to minimize the down side risk. The integration of crop insurance products and marketing alternatives create a synergy at the lower levels of value at risk, where the down side risk is located. However, the use of integrated strategies does not increase the chances of achieving a cash flow breakeven gross revenue per acre over the base strategy, which did not include insurance or marketing alternatives. The breakeven level is not reached until the 70 percent level, which means that 7 out of 10 years, the farm will not cash flow. Output from the Bullock and AgRisk models are similar. This study may be used as a guide for producers and analysts in studying risk management strategies. To assist in the individual decision making process, further study will need to be done with yield data and budgets for the individual farm.risk, management, strategy, yield, price, insurance, market, Risk and Uncertainty,

Rip/singularity free cosmology models with bulk viscosity

In this paper we present two concrete models of non-perfect fluid with bulk viscosity to interpret the observed cosmic accelerating expansion phenomena, avoiding the introduction of exotic dark energy. The first model we inspect has a viscosity of the form ${\zeta} = {\zeta}_0 + ({\zeta}_1-{\zeta}_2q)H$ by taking into account of the decelerating parameter q, and the other model is of the form ${\zeta} = {\zeta}_0 + {\zeta}_1H + {\zeta}_2H^2$. We give out the exact solutions of such models and further constrain them with the latest Union2 data as well as the currently observed Hubble-parameter dataset (OHD), then we discuss the fate of universe evolution in these models, which confronts neither future singularity nor little/pseudo rip. From the resulting curves by best fittings we find a much more flexible evolution processing due to the presence of viscosity while being consistent with the observational data in the region of data fitting. With the bulk viscosity considered, a more realistic universe scenario is characterized comparable with the {\Lambda}CDM model but without introducing the mysterious dark energy.Comment: 9 pages, 6 figures, submitted to EPJ-