Quest for the piroplasms in camels: identification of Theileria equi and Babesia caballi in Jordanian dromedaries by PCR

DNA of two species of piroplasmids was detected in dromedaries during a survey of blood protozoans in Jordan between 2007 and 2009. Ten clinically healthy camels (10%) originating from three Jordanian districts were found, using a PCR assay, to harbor Theileria or Babesia species in their blood and no mix infection was determined. Analysis of the partial 18S rRNA gene sequences of these parasites allowed their unambiguous identification as equine piroplasmids Babesia caballi (n=6) and Theileria equi (n=4). In case of latter species, a novel genotype was found in horses. This first molecular-based species determination of piroplasmids from camels further contributes to the growing evidence of low host specificity of piroplasmids.     

Breeding for a more energy efficient greenhouse tomato: past and future perspectives

Energy efficiency can be increased either by increasing the production per m² or by reducing the energy input per m², e.g. by reducing temperature set-points in the greenhouse. So far, in Dutch glasshouse tomatoes energy efficiency was almost exclusively raised by yield increases. To study the role of tomato breeding in this production increase, yield and underlying components of 7 cultivars released between 1950 and 2002 were studied. Furthermore, variation in temperature response between cultivars was studied. In three experiments yield and biomass production of in total 11 cultivars were evaluated at two temperature regimes (17/15°C and 21/19°C day/night temperature set-points). Breeding has resulted in a remarkable increase in production. Under current conditions, yield of modern cultivars was on average 40% higher than yield of ‘Moneymaker’, released in 1950. This increase in production resulted from a higher light use efficiency. Although the fraction of assimilates partitioned to the fruits showed small differences between cultivars, this trait was not related to year of release. Furthermore, more recently introduced cultivars produced larger fruits rather than more fruits. All cultivars responded similar to both temperature regimes for all important characteristics, limiting the possibilities of using existing cultivars in a breeding program for improved yield at lower temperatures.     

Altitudinal variability of stand structure and regeneration in the subalpine spruce forests of the Pol’ana biosphere reserve,Central Slovakia

The structure of natural subalpine spruce forest in the Zadná Pol’ana massif of the Western Carpathians was analysed. We focused on the variability of different aspects of stand structure, tree decay and regeneration processes in altitudinal gradient. We used systematic sampling, covering an area of 2 km², to detect even subtle changes in stand structure within one forest type over a range of less than 200 m in elevation. Mean stand density was 290 trees (>7 cm DBH) per hectare, average basal area was 41 m² ha⁻¹, and the volume accumulation in living trees amounted to 500 m³/ha⁻¹. Stand volume decreased by more than 50% between 1,260 and 1,434 m a.s.l. This means for an increase of altitude of 100 m that stand volume decreased by nearly 200 m³. Neither stand density nor basal area was related to elevation. Maximum tree height was strongly correlated to elevation, and it decreased on average by 6 m for each 100 m increment of altitude. No significant changes in the maximum spruce diameter were recorded in relation to the elevation gradient. Spatial distribution of trees was biased toward regularity at lower altitudes. Tree clustering increased with increasing altitude. The stock of coarse woody debris (CWD) decreased slightly along the altitudinal gradient, but changes were not significant. Density of spruce saplings and their number growing on CWD significantly increased across the elevation gradient. Despite the fact that the analysed forest tract was relatively large, highly variable in respect to environmental factors, and that stand volume, spatial structure, and tree height displayed strong variability along the elevation gradient, the diameter structure of stands and regeneration measures were uniform. Our results suggest that the recruitment of new trees in the Zadná Pol’ana subalpine spruce forest is not temporally continuous even at a scale of several square kilometres.     

Zur Kenntnis der Wechselbezichungen zwischen Bodenschädlingen,Unkräntern und deren BekämpfungsmaBnahmennahmen

Summary Although our investigations may be considered as orientation work only and we are still well aware of the fact that a new problem has been merely touched by us, we are convinced that there exists an evident dependency among weeds, soilpests and their control measures. The application of soil insecticides may in some cases increase the quantity of weeds on the treated surfaces considerably, whilst the application of herbicides may also increase the noxiousness of different soil insects. Since an intensified application of herbicides often involves a larger application of soil insecticides and vice versa, an application of soil insecticides may increase the necessity of herbicides applications. In our opinion a continuation and enlargement of such studies is very important, for only by knowing perfectly the complete biological action of every pesticide upon the whole complex of noxious and useful organisms, influencing directly or indirectly the development of cultured plants, pesticides can be used without provoking the danger of unforeseen negative effects. That is the preliminary condition for a really directed or integral plant protection in which one must know exactly what will be achieved by a protective measure. Although the terms directed or integral protection are today mainly used in connection with orchards and vineyards, they should be fully extended to cover the soil too, regardless whether annual plants which are the subject of less serious disturbances of the biocenosis are growing on it. In our opinion disturbances in the soil can be as hard to put in order as those in orchards or vineyards. Therefore it is very important to apply correctly all pesticides which are used for soil treatments, considering all negative effects which may accompanying them. Disturbances or changes in the balance of biocenosis of all organisms living in or on the soil must be particularly taken into consideration.

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Auf dem 6. Intern. Pflanzenschutzkongre?, Wien, 1967 gehaltener Vortrag.     

Über die Wirkung von Bacillus thuringiensis kombiniert mit synthetischem Pyrethroid auf Orgyia antiqua L.

The efficacy of the biopreparations Dipel and Thuricide HP in combination with the pyrethroid Permethrin, and that of Permethrin in the control ofOrgyia antiqua larvae has been tested in the field. The results indicate that these preparations may replace satisfactorily insecticides of the group of chlorated carbohydrates, and organophosphates, in the control ofOrgyia larvae. The persistence of spores of both Dipel and Thuricide was found to be good on the pine needles. The main advantage of the tested preparations is their complete harmlessness to vertebrates. Since they do not contaminate the external environment, they can be used safely in the treatment of large areas of infected forest stands located at the site of important water resources and recreation areas.     

Dynamics of seed imbibition and germination of Austrian pine (<Emphasis Type="Italic">Pinus</Emphasis><Emphasis Type="Italic">nigra</Emphasis> Arnold) from extreme habitat conditions within five Balkan provenances

Seed was collected from two habitat types (harsh/rocky and favorable/control) within five Balkan provenances. An experiment was conducted to examine water uptake (grams water per gram of fresh seed) during 48 h after exposure to water. A second experiment investigated the effect of simulated-drought conditions (4% sucrose solution) compared to non-drought conditions (distilled water) on subsequent germination percentage. Seed from rocky habitats had less water uptake than those from control habitats for three of the provenances. However, water uptake was not correlated with subsequent germination. Drought simulation decreased germination but patterns for seed within each provenance were similar to germination under non-drought conditions. With the exception of one provenance, seed from the rocky habitats had lower germination than seed from control habitats. The data suggests some degree of adaptation to environmental conditions although variability was very high within each provenance’s habitat types. This is of particular importance when considering potential impacts of climate change and the anticipated migration of species due to changes in habitat.