Looking for ecological control of carrot psyllid

The results suggest that a one-week trap replacement period, which is the current practise in carrot psyllid monitoring, is too long at the early growth stages of carrot. Regardless of the oviposition (laying of eggs) preference for a certain carrot cultivars, the possibility of a functional push-pull control strategy based on limonene seems unlikely, since the repellent effect of limonene could not be verified. Further field studies with possible repellent compounds, such as winter host volatiles, will be needed to develop an efficient ecological control method for this species

Robust Control and Persistence in the New Keynesian Economy

Since Keynes no economist would deny that expectations under uncer- tain conditions matter for the conduct of monetary policy, but still opin- ions about their formation are diverse. We build a hybrid New Keynesian Framework to analyze the influence of model uncertainty on optimal in- terest rates under di¤erent degrees of rational forward-looking behavior, using recently developed robust control techniques. Impulse response functions illustrate that uncertainty seems to be a rationale for more aggressive interest rate reactions, but also suggest that the degree of forward-looking behavior seems to be more important than an appro- priate fear about the misspecification of a given model. Furthermore, we argue that assuming to control inflation through expectations is a policy on the razor's edge, since robust expectations overestimate shock impacts. This questions the gains from commitment under uncertainty.Robust Control, Knightian Uncertainty, Monetary Policy, Forward-Looking Expectations, Model Uncertainty.

Brassicas limited in weed control

This article discusses the limitations of using brassica cover crops for weed control. A brief overview of the role of cover crops is provided, followed by a short review of research looking at brassica cover crops

Optimizing crop loading of apples and pears - results 2004-2006 (foliar fertilizers, thinning)

Main topics of the research-project FuE 03OE088 of “Bundesprogramm Ökologischer Landbau” (30.04.2004-31.12.2006) were the testing of foliar fertilizers in organic apples and pears, optimizing lime sulphur for blossom thinning, looking for alternatives to lime sulphur for blossom thinning and looking at different combinations of thinning measures. Only the results of testing foliar fertilizers (carried out by KoGa Ahrweiler and OVB/ÖON Jork) and combinations of thinning measures (carried out by LVWO Weinsberg) are described in this article. Over three years only a small increase in yield was evaluated for the fertilizers Aminosol PS and Wuxal Ascofol (site Ahrweiler, apple variety ‘Elstar’). In Jork (apple variety ‘Holsteiner Cox’) yield could only be judged in 2005 and 2006. Wuxal Ascofol showed some advantage in comparison to the control. At pear variety ‘Conference’ no clear tendencies could be seen, the control had the highest yield. In 2005 the fruitsetting of ‘Conference’ was very low because of bad conditions during blossom

Learning, endogenous indexation and disinflation in the New-Keynesian Model

This paper introduces adaptive learning and endogenous indexation in the New-Keynesian Phillips curve and studies disinflation under inflation targeting policies. The analysis is motivated by the disinflation performance of many inflation-targeting countries, in particular the gradual Chilean disinflation with temporary annual targets. At the start of the disinflation episode price-setting firms’ expect inflation to be highly persistent and opt for backward-looking indexation. As the central bank acts to bring inflation under control, price-setting firms revise their estimates of the degree of persistence. Such adaptive learning lowers the cost of disinflation. This reduction can be exploited by a gradual approach to disinflation. Firms that choose the rate for indexation also re-assess the likelihood that announced inflation targets determine steady-state inflation and adjust indexation of contracts accordingly. A strategy of announcing and pursuing short-term targets for inflation is found to influence the likelihood that firms switch from backward-looking indexation to the central bank’s targets. As firms abandon backward-looking indexation the costs of disinflation decline further. We show that an inflation targeting strategy that employs temporary targets can benefit from lower disinflation costs due to the reduction in backward-looking indexation