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Evaluation of semiochemical based push-pull strategy for population suppression of ambrosia beetle vectors of laurel wilt disease in avocado.
Ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) bore into tree xylem to complete their life cycle, feeding on symbiotic fungi. Ambrosia beetles are a threat to avocado where they have been found to vector a symbiotic fungus, Raffaelea lauricola, the causal agent of the laurel wilt disease. We assessed the repellency of methyl salicylate and verbenone to two putative laurel wilt vectors in avocado, Xyleborus volvulus (Fabricius) and Xyleborus bispinatus (Eichhoff), under laboratory conditions. Then, we tested the same two chemicals released from SPLAT flowable matrix with and without low-dose ethanol dispensers for manipulation of ambrosia beetle populations occurring in commercial avocado. The potential active space of repellents was assessed by quantifying beetle catch on traps placed 'close' (~5-10 cm) and 'far' (~1-1.5 m) away from repellent dispensers. Ambrosia beetles collected on traps associated with all in-field treatments were identified to species to assess beetle diversity and community variation. Xyleborus volvulus was not repelled by methyl salicylate (MeSA) or verbenone in laboratory assays, while X. bispinatus was repelled by MeSA but not verbenone. Ambrosia beetle trap catches were reduced in the field more when plots were treated with verbenone dispensers (SPLAT) co-deployed with low-dose ethanol dispensers than when treated with verbenone alone. Beetle diversity was highest on traps deployed with low-dose ethanol lures. The repellent treatments and ethanol lures significantly altered the species composition of beetles captured in experiment plots. Our results indicate that verbenone co-deployed with ethanol lures holds potential for manipulating ambrosia beetle vectors via push-pull management in avocado. This tactic could discourage immigration and/or population establishment of ambrosia beetles in commercial avocado and function as an additional tool for management programs of laurel wilt
Proizvodnja inokoluma ektomikoriza gljiva uzgojem na krutoj podlozi i submerznom fermentacijom
Ectomycorrhizal fungi are very important for forestry practices. In order to develop controlled mycorrhization practices it is necessary to isolate and select ectomycorrhizal fungi that are able to colonize the intended plant species and that are efficient in promoting its growth under the environmental conditions prevailing in the plantation site. To be suitable for the inoculation of nursery seedlings, these fungi must be able to grow rapidly during large-scale cultivation and maintain high infectivity rates during storage. Even though several decades have passed since the first field-scale mycorrhizal experiments, the routine use of these fungi to inoculate plants is still not very common. The lack of suitable ectomycorrhizal inoculants in the market is one of the main factors contributing to this situation. This review presents and discusses techniques for the production and application of ectomycorrhizal inoculants, as well as the more recent studies aimed at developing reliable industrial production processes.Ektomikorize gljiva su vrlo važne u šumarstvu. Za razvoj kontroliranih mikoriza potrebno je izolirati i odabrati gljive što mogu kolonizirati ciljanu vrstu biljaka i koje uspješno rastu u plantažnim uvjetima. Da bi se mogle koristiti za inokulaciju biljaka u rasadniku, gljive moraju brzo rasti i u velikim količinama tijekom uzgoja te zadržavati veliku infektivnost pri skladištenju. Iako je prošlo više desetljeća od prvog mikoriznog pokusa na polju, još uvijek nije raširena upotreba tih gljiva za inokulaciju biljaka. Glavni uzrok tomu je nedostatak prikladnog ektomikoriznog inokulanta na tržištu. U ovom je revijalnom prikazu dan pregled i rasprava o tehnikama proizvodnje i primjeni ektomikoriznih inokulanata, te o najnovijim istraživanjima kako bi se u industriji razvili pouzdani proizvodni procesi
Contagion, Bank Lending Spreads and Output Fluctuations
This paper studies the effects of contagion on bank lending spreads and output fluctuations in Argentina. The first part presents the analytical framework, which analyzes the determination of bank lending spreads in the presence of verification and enforcement costs of loan contracts. The second part presents estimates of a vector autoregression model that relates the ex ante bank lending spread, the cyclical component of output, the real bank lending rate, and the external interest rate spread. The effects of a contagious shock (modeled as a positive historical shock in the external interest rate spread) are analyzed using generalized impulse response functions. The sock is shown to lead to an increase in domestic spreads and a reduction in the cyclical component of output. These results are consistent with the predictions of our analytical framework.
Pollution, Public Health Care, and Life Expectancy When Inequality Matters
We analyze the link between economic inequality in terms of wealth, life expectancy, health care and pollution. The distribution of wealth is decisive for the number of households investing in human capital. Moreover, the willingness to invest in human capital depends on agents' life expectancy which determines the length of the amortization period of human capital investments. Life expectancy is positively affected by public health care expenditures but adversely affected by the pollution stock generated by aggregate production. Our model accounts for an endogenous take-off in terms of human capital investments. Higher initial inequality delays the take-off because a given set of policies (abatement measures and public health care) is less effective in improving agents' survival probabilities. We compare a change in taxes to a change in expenditure shares on health hand abatement given different amounts of (initial) inequality. The advantage of the latter as compared to the former is the achieved increase in the tax base which induces more expenditures on health care and abatement measures, such that an even higher economic activity is compatible with a similar level of long-run pollution
Sources of pro-cyclicality in east Asian financial systems
Procyclicality is a normal feature of economic systems, but financial sector
weaknesses can exacerbate it sufficiently to pose a threat to macroeconomic and financial
stability. These include shortcomings in bank risk management and governance, in
supervision and in terms of dependence on volatile sources of funds. The paper tests
econometrically for the importance of such features leading to pro-cyclicality in the financial
systems of 11 East Asian countries. This analysis makes it possible to identify specific policy
measures for East Asian countries that could limit the extent to which financial systems
exacerbate pro-cyclicality
Insect pest management with sex pheromone precursors from engineered oilseed plants
Pheromones have become an environmentally friendly alternative to conventional insecticides for pest control. Most current pheromone-based pest control products target lepidopteran pests of high-value crops, as today’s manufacturing processes cannot yet produce pheromones at low enough costs to enable their use for lower-value crops, especially commodity crops. Camelina sativa seeds genetically modified to express (Z)-11-hexadecenoic acid, a sex pheromone precursor of several moth species, provided the oil from which the precursor was isolated, purified and transformed into the final pheromone. Trap lures containing this pheromone were then assessed for their capacity to manage moth pests in the field. Plant-derived pheromone lures proved equally effective as synthetic pheromone lures in monitoring the diamondback moth, Plutella xylostella, in cabbage and disrupting mating of cotton bollworm, Helicoverpa armigera, in common bean fields. Our study demonstrates the biological efficacy and economic feasibility of pheromone production in plant factories by metabolic engineering of an oilseed crop
PRIVATE SAVINGS IN TRANSITION ECONOMIES: ARE THERE TERMS OF TRADE SHOCKS?
The paper examines the impact of terms of trade shocks on private savings in the transition economies after accounting for the effect of other determinants. Economic agents in the transition economies are subject to tight credit constraints which are more pronounced during bad state of nature. Thus, adverse shocks to commodity prices in the world market can force them to reduce savings by a larger amount than they would otherwise have. Empirical analysis using a dynamic panel model and data from twenty one transition economies confirm that most of the determinants of savings identified in the literature also apply to the transition economies. Favorable movements in both the permanent and transitory components of the terms of trade have a significant positive impact on private savings with transitory movements having a larger impact than the permanent component. This reflects the lack of access to foreign borrowing that many of the transition economies have faced during the last decade. Although the impact of terms of trade shocks are found to be asymmetric, the magnitude of the impact appears to be small. The results are robust for alternative estimators, determinants, and country groupings.http://deepblue.lib.umich.edu/bitstream/2027.42/39958/3/wp572.pd
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