Fruitgrowers towards a new approach to enhance biodiversity in organic orchards

In the frame of the project “Arbeitsnetz zur Weiterentwicklung der Anbauverfahren des ökologischen Obstbaus” (BOEL-project Nr. 03OE178) a group of fruitgrowers and advicers started to discuss new measures and new concepts to enhance biodiversity in organic orchards. Strips with flowering plants that can be integrated in the normal mulching system and thus, do not originate vole problems, are actually tested on the farms. Other measures as single bushes at the top and end of the rows are in discussion. If such measures are to be integrated successfully in the practice of organic fruit growing, the impulse must spring from growers themselves and their requirements regarding the different risks must be considered. Otherwise, an acceptance in practice is not very probable. This activites are reported here since we want more people to join us

Codling moth populations less susceptible to CpGV: What about higher concentrations?

In an organic orchard with a codling moth (CM) population less susceptible to CpGV it was tested, whether an increased dosage of CpGV by factor 10 would result in any increased efficacy. The applications were set in shorter than weekly intervals with 10 ml/ha Madex (low dosage plot) and 100 ml/ha Madex (high dosage plot). The higher dosage showed also a better efficacy, especially on the “active damage” (live larvae). The orchard where the experiments were conducted was known to have a less susceptible CM population (2004) although there were no serious CM problems reported by the farmer despite the CM control was done only with CpGV. It was investigated, whether natural antagonists might have been a reason for the absence of serious problems in this orchard. No signs of a strong presence of other antagonists were found but CM the population was increasing very much in the year the experiment was conducted (2005). Thus, probably the reason for the absence of CM problems seems to be just a delayed increase of the CM population after the development of a lower susceptibility of CM against CpGV

Experiences with entomopathogenic nematodes for the control of overwintering codling moth larvae in Germany

Entomopathogenic nematodes were tested for their potential as tool in resistance management of codling moth Cydia pomonella L. in organic fruit growing. In two field tests, the adults emerging from stems treated with nematodes were monitored. In one trial, 90 % of efficacy could be shown. On-farm trials with favourable weather conditions showed an efficacy about 50-60 % on fruit infestation by codling moth in the year following the application. On-farm trials with unfavourable weather conditions showed no results. The favourable weather conditions for the application are discussed with reference to German conditions

Field tests with Madex Plus against CpGV-resistant codling moth populations in organic orchards in 2006

When resistance to the Mexican isolate of Cydia pomonella Granulovirus (CpGV-M) arose in several organic orchards in Germany in 2004 and 2005, the future of codling moth control became a serious concern of organic fruit growing. In 2006, a new virus isolate from Andermatt Biocontrol AG (Madex Plus) was first tested in two field trials in organic orchards on codling moth populations resistant against the Mexican isolate of CpGV. Madex Plus showed a better efficacy on these populations than Madex 3. However, larval mortality larvae seemed to be somewhat delayed. A very good effect was shown in population control. The number of larvae in corrugated card board belts was significantly reduced after treatment with Madex Plus. In addition to these trials, on-farm trials in all orchards concerned of the CpGV-M resistance were carried out. The results of on-farm trials showed the same tendency: high efficacy in population control against a background of slightly delayed larval death. In 2007, Madex Plus was applied successfully in all organic orchards with CpGV-M-resistant codling moth populations in Germany

Impact of different Agents on the Efficacy of Codling Moth Granulovirus in Tank Mixtures

In the control of codling moth it is common to combine the granulovirus with other agents, especially fungicides, in spray application. Therefore the knowledge about the influence of these agents on the efficacy of the virus in tank mix is very important. Studies on this subject were part of a project supported by BMELV (German Federal Ministry for Food, Agriculture and Consumer protection) at the Institute for Biological Control of JKI in Darmstadt. The granulovirus of Cydia pomonella (L.) (CpGV) was mixed with 10 different agents at concentrations as applied in the field. After the exposure the virus activity was calculated from larval mortality determined in bioassays with neonates of a susceptible codling moth strain. Only two agents with a pH of 11 (sodium silicate (water glass) and calcium polysulfide (lime sulphur)) reduced the virulence of CpGV significantly

Environmental and fishing effects on the dynamic of brown tiger prawn (Penaeus esculentus) in Moreton Bay (Australia)

This analysis of the variations of brown tiger prawn (Penaeus esculentus) catch in the Moreton Bay multispecies trawl fishery estimated catchability using a delay difference model. It integrated several factors responsible for variations in catchability: targeting of fishing effort, increasing fishing power and changing availability. An analysis of covariance was used to define fishing events targeted at brown tiger prawns. A general linear model estimated inter-annual variations of fishing power. Temperature induced changes in prawn behaviour played an important role in the dynamic of this fishery. Maximum likelihood estimates of targeted catchability ($3.92 \pm 0.40 \ 10^{-4}$ boat-days$^{-1}$) were twice as large as non-targeted catchability ($1.91 \pm 0.24 \ 10^{-4}$ boat-days$^{-1}$). The causes of recent decline in fishing effort in this fishery were discussed.Comment: revised manuscript following reviewers comments + adding data and code for reader

Control of the apple sawfly Hoplocampa testudinea Klug in organic fruit growing

The best application technique and application data for the treatments with Quassia extract against the apple sawfly Hoplocampa testudinea Klug were tested. The spraying solution was distributed best on the receptacle of the blossom – the place where the sawfly larvae feed before the enter the blossom – when the treatment was effecttuated at fading blossom with a high amount of water (about 500 l/ha/mTh). The addition of T/S forte, a wetting agent, could also improve the efficacy of Quassia treatments in a lower dose. Thus, it is recommended to apply in fading blossom with addi-tion of T/S forte and high amounts of water to obtain the best effect. If the conditions for applica-tions are good and the infestation is not too high, the normally recommended dose of 6 g/ha/mTh can even be reduced

Efficacy of Quassia extract on the apple sawfly Hoplocampa testudinea Klug

The efficacy of Quassia extract with a standardized content of Quassin was proved in various field trials in different regions during three years. The amount of Quassin of 6 g/ha/m tree height will be recommended to practice. It is not important to have a contact effect on the eggs. The larvae must feed on the product before they enter the fruit. There is a very good efficacy on primaray infestation. Furthermore, there is even an efficacy on secondary infestation. Thus, even if due to difficult conditions during application or not optimal termination of the treatment the efficacy on the primary infestation is not entirely sufficient, the secondary infestation will be controlled better

Wirkung von Quassiaextrakt auf die Apfelsägewespe Hoplocampa testudinea Klug

The efficacy of Quassia extract with a standardized content of Quassin was proved in various field trials in different regions during three years. The amount of Quassin of 6 g/ha/m tree height will be recommended to practice. It is not important to have a contact effect on the eggs. The larvae must feed on the product before they enter the fruit. There is a very good efficacy on primaray infestation. Furthermore, there is even an effi-cacy on secondary infestation. Thus, even if due to difficult conditions during application or not optimal ter-mination of the treatment the efficacy on the primary infestation is not entirely sufficient, the secondary in-festation will be controlled better

Direct Distances to Cepheids in the Large Magellanic Cloud: Evidence for a Universal Slope of the Period-Luminosity Relation up to Solar Abundance

We have applied the infrared surface brightness (ISB) technique to derive distances to 13 Cepheids in the LMC which span a period range from 3 to 42 days. From the absolute magnitudes of the variables calculated from these distances, we find that the LMC Cepheids define tight period-luminosity relations in the V, I, W, J and K bands which agree exceedingly well with the corresponding Galactic PL relations derived from the same technique, and are significantly steeper than the LMC PL relations in these bands observed by the OGLE-II Project in V, I and W, and by Persson et al. in J and K. We find that the tilt-corrected true distance moduli of the LMC Cepheids show a significant dependence on period, which hints at a systematic error in the ISB technique related to the period of the stars. We identify as the most likely culprit the p-factor which converts the radial into pulsational velocities; our data imply a much steeper period dependence of the p-factor than previously thought, and we derive p=1.58 (+/-0.02) -0.15 (+/-0.05) logP as the best fit from our data, with a zero point tied to the Milky Way open cluster Cepheids. Using this revised p-factor law, the period dependence of the LMC Cepheid distance moduli disappears, and at the same time the Milky Way and LMC PL relations agree among themselves, and with the directly observed LMC PL relations, within the 1 sigma uncertainties. Our main conclusion is that the previous, steeper Galactic PL relations were caused by an erroneous calibration of the p-factor law, and that there is now evidence that the slope of the Cepheid PL relation is independent of metallicity up to solar metallicity, in both optical, and near-infrared bands.Comment: ApJ accepte