Influence of rootstock on the susceptibility of sweet cherry scions to bacterial canker, caused by Pseudomonas syringae pvs morsprunorum and syringae

In a field trial to determine whether the rootstock influenced the susceptibility of cherry cultivars to bacterial canker three cultivars (Napoleon, Roundel and JI 14039), each grafted on two rootstocks (F 12/1 and Colt), were subjected to natural infectionand to inoculation with three bacterial canker pathogens (Pseudomonas syringae pv. morsprunorum races 1 and 2 and P. syringae pv. syringae). Inoculations were made through leaf scars and through wounds. The high susceptibility of Napoleon and high resistance of JI 14039 were confirmed. Napoleon was more susceptible to inoculation through branches when on F12/1 than when on Colt but the reverse was true for leaf scar inoculations. JI14039 was more susceptible to race 1 inoculated through leaf scars when grown on F12/1 than when on Colt. No rootstock/scion interaction was detected with Roundel.
The complexity of the relationships between the pseudomonad pathogens and their cherry hosts is briefly discussed.     

MAGNETIC RESONANCE IMAGING CHARACTERISTICS OF PERIPHERAL NERVE SHEATH TUMORS OF THE CANINE BRACHIAL PLEXUS IN 18 DOGS

Magnetic resonance imaging (MRI) examinations from 18 dogs with a histologically confirmed peripheral nerve sheath tumor (PNST) of the brachial plexus were assessed retrospectively. Almost half (8/18) had a diffuse thickening of the brachial plexus nerve(s), six of which extended into the vertebral canal. The other 10/18 dogs had a nodule or mass in the axilla (1.2-338 cm3). Seven of those 10 masses also had diffuse nerve sheath thickening, three of which extended into the vertebral canal. The majority of tumors were hyperintense to muscle on T2-weighted images and isointense on T1-weighted images. Eight of 18 PNSTs had only minimal to mild contrast enhancement and many (13/18) enhanced heterogeneously following gadolinium DTPA administration. Transverse plane images with a large enough field of view (FOV) to include both axillae and the vertebral canal were essential, allowing in-slice comparison to detect lesions by asymmetry of structures. Higher resolution, smaller FOV, multiplanar examination of the cervicothoracic spine was important for appreciating nerve root and foraminal involvement. Short tau inversion recovery, T2-weighted, pre and postcontrast T1-weighted pulse sequences were all useful. Contrast enhancement was critical to detecting subtle diffuse nerve sheath involvement or small isointense nodules, and for accurately identifying the full extent of disease. Some canine brachial plexus tumors can be challenging to detect, requiring a rigorous multiplanar multi-pulse sequence MRI examination.     

Tree growth and stand development of four Populus clones in large monoclonal plots

Four clones of Populus were planted in replicated monoclonal plots near Olympia, WA, to evaluate their suitability for use in short-rotation culture. All clones were easily established and had minimal problems from damaging agents during the first five years. Observed differences among clones in pattern and amount of growth appeared to be associated with differences in number and density of buds, sylleptic branching, and phenology. In addition, differences in drought tolerance and stockability may also have influenced clonal differences in annual growth and stand productivity. Individual tree growth was limited by the dense 1.0-m spacing, but the best-growing clones averaged 13 to 16 m tall, 7 to 9 cm in breast-high diameter (1.3 m), and produced stand basal areas exceeding 38 m²ha^-1at 8 years. Mortality was negligible for 7 years, after which various combined effects of competition, stem borer damage (Cryptorhyncus lapathi), and a severe windstorm caused mortality ranging from 18 to 36% in the three fastest growing clones.     

Erythrocyte sedimentation rate in the dog and cat: Comparison of two methods and influence of packed cell volume, temperature and storage of blood

Erythrocyte sedimentation rates of canine and feline blood were measured by the Wintrobe method and by a capillary method utilizing 75 times 1 mm microhaematocrit tubes. Results obtained with each method were generally similar for both species.
The erythrocyte sedimentation rate (ESR) with the Wintrobe method as well as with the capillary method was inversely related to the packed cell volume (PCV), i. e., the lower the PCV, the higher the ESR. However, there was no consistent relationship between the ESR values obtained by the two methods at all levels of PCV. Wintrobe ESR values were slightly higher than capillary tube values for canine blood having a PCV of 36-60% and for 'reconstituted' canine and feline bloods having a high PCV. In contrast, capillary tube ESR values were slightly higher than Wintrobe values for 'reconstituted' canine blood having a PCV of 8-38 % and for feline blood with a PCV below 30%. It was, therefore, concluded that ESR values obtained by the two methods cannot be considered equivalent.
Only a slight decrease occurred in the ESR of blood held at 4°C for 2-6 hours, whereas the ESR of blood held at room temperature dropped markedly and blood stored for 24 hours at either temperature consistently gave lower values. Therefore, it is recommended that if the ESR cannot be determined soon after sampling, the blood should be stored at 4°C and the test conducted within 6 hours.     

The effect of crown gall on growth of cherry trees

Over 1000 cherry trees, as rootstocks, nursery sweet cherry or ornamental cultivars or orchard trees up to 7 years old, with or without galls, were examined to determine the effect, if any, of crown gall disease on tree growth. No clear, consistent differences between healthy and galled trees were found. Healthy 1-year-old F12/ 1 rootstocks were smaller than their galled counterparts but the reverse was true for 2-year-old sweet cherries and ornamental cultivars. The mean girth of non-galled 6-year-old trees of cv Schrecken was greater than that of galled trees from the same orchard. Detailed records on two sweet cherry cultivars, Napoleon and Roundel, revealed some differences in growth rate in the early years between healthy trees and those with various levels of galling at planting, but these differences were not sustained. Irrespective of gall status at planting no correlation was detected between final gall status and ultimate tree size. The data support the view that there is no consistent effect of crown gall on cherry tree growth and that the adverse appearance of affected nursery material is the main problem with this disease.