Tolerance of black, cranberry, kidney, and white bean to cloransulam-methyl

The level of tolerance of various market classes of dry bean to cloransulam-methyl is not known. Three field studies were conducted in Ontario, Canada during 2007 and 2008 to determine the level of tolerance of black, cranberry, kidney, and white bean to the pre-emergence (PRE) and postemergence (POST) application of cloransulam-methyl at 17.5, 35, and 70 g ai ha⁻¹. Cloransulam-methyl applied at 17.5, 35, and 70 g ha⁻¹ caused between 13 and 23% injury in black, cranberry, kidney, and white bean, respectively. Cloransulam-methyl applied at 17.5, 35, and 70 g ha⁻¹ reduced the shoot dry weight by between 16 and 28% compared to the untreated control. Cloransulam-methyl applied PRE reduced the height of black bean by 27% and the height of cranberry bean by 25% at 70 g ha⁻¹ and reduced the height of white bean by 19% at 35 g ha⁻¹ and by 37% at 70 g ha⁻¹. Cloransulam-methyl applied PRE reduced the yield of black bean by 29% at 35 g ha⁻¹ and by 43% at 70 g ha⁻¹, reduced the yield of cranberry bean by 43% at 70 g ha⁻¹, and reduced the yield of white bean by 36% at 35 g ha⁻¹ and by 54% at 70 g ha⁻¹. Based on these results, there is not an adequate margin of crop safety for the PRE and POST application of cloransulam-methyl in black, cranberry, kidney, and white bean at the rates evaluated.     

Control of the invasive liana, Hiptage benghalensis

The liana, hiptage ( Hiptage benghalensis ), is currently invading the wet tropics of northern Queensland and remnant bushland in south-eastern Queensland, Australia. Trials using seven herbicides and three application methods (foliar, basal bark, and cut stump) were undertaken at a site in north Queensland (158 700 hiptage plants ha⁻¹). The foliar-applied herbicides were only effective in controlling the hiptage seedlings. Of the foliar herbicides trialed, dicamba, fluroxypyr, and triclopyr/picloram controlled >75% of the treated seedlings. On the larger plants, the cut stump applications were more effective than the basal bark treatments. Kills of >95% were obtained when the plants were cut close to ground level (5 cm) and treated with herbicides that were mixed with diesel (fluroxypyr and triclopyr/picloram), with water (glyphosate), or were applied neat (picloram). The costings for the cut stump treatment of a hiptage infestation (85 000 plants ha⁻¹), excluding labor, would be $A14 324 ha⁻¹ using picloram and $A5294 ha⁻¹ and $A2676 ha⁻¹, respectively, using glyphosate and fluroxypyr. Foliar application using dicamba for seedling control would cost $A1830 ha⁻¹. The costs range from 2–17 cents per plant depending on the treatment. A lack of hiptage seeds below the soil surface, a high germinability (>98%) of the viable seeds, a low viability (0%) of 2 year old, laboratory-stored fruit, and a seedling density of 0.1 seedlings m⁻² 12 months after a control program indicate that hiptage might have a short-term seed bank. Protracted recolonization from the seed bank would therefore be unlikely after established seed-producing plants have been controlled.     

Modelling the transport of larval sandeels on the north-west European shelf

This study considers the interannual variability in the advection of sandeel ( Ammodytes marinus ) larvae on the north-west European shelf. We use recently collated data on spawning location, age of larvae and the time of hatching (between 1955 and 1993) as input to a particle-tracking model. Utilizing hourly currents from a 39 year run of a two-dimensional sea circulation model, cohorts of sandeel larvae were represented as a distribution of particles in space and time, and particle drift was calculated for the larval life stage. The final distributions of particles were compared with actual distributions of 0-group sandeels in the North Sea, as determined from surveys conducted at around the end of the larval phase. Preliminary examination of the data between 1973 and 1993 indicates that differences in predicted drift could explain some of the large interannual variability in 0-group distributions. This approach may help to improve our understanding of the frequent colonization events that are typical of this species.     

Flat fan and air induction nozzles affect soybean herbicide efficacy

Fifteen field experiments were conducted from 2002 to 2005 to determine the influence of the nozzle type, spray volume, spray pressure, and herbicide rate on herbicidal efficacy in soybean. There was no effect of the nozzle type on herbicidal efficacy with fomesafen, bentazon, glyphosate, and cloransulam‐methyl when applied at the manufacturer's recommended rate. The control of Echinochloa crus‐galli (barnyardgrass) with quizalofop‐p‐ethyl was improved when applied with flat fan (FF) nozzles compared with air induction (AI) nozzles. There was an increase in weed control with the FF nozzles compared with the AI nozzles in four of the 13 comparisons when the herbicides were applied at half the recommended rate, while in two situations, application with the AI nozzles resulted in improved weed control. With the FF nozzles, there was no effect of the water carrier volume on weed control with bentazon, glyphosate, and cloransulam‐methyl. The control of Abutilon theophrasti (velvetleaf) and Chenopodium album (common lambsquarters) with fomesafen and E. crus‐galli with quizalofop‐p‐ethyl was improved at the higher water carrier volume. With the AI nozzles, the control of A. theophrasti and Ambrosia artemisiifolia (common ragweed) with fomesafen and E. crus‐galli with quizalofop‐p‐ethyl was improved at the higher water carrier volume, while the control of A. theophrasti and Polygonum persicaria (ladysthumb) was improved with glyphosate at the lower water carrier volume. With the AI nozzles, the control of C. album with bentazon and E. crus‐galli with quizalofop‐p‐ethyl was improved at the higher spray pressure. There was no effect of the nozzle type on the soybean yield with glyphosate, cloransulam‐methyl, and quizalofop‐p‐ethyl. The use of the FF nozzles compared with the AI nozzles to apply fomesafen and bentazon increased the soybean yield by 6 and 7%, respectively. Based on this study, the optimum nozzle type, water carrier volume, and spray pressure is herbicide‐ and weed species‐specific.     

Biomechanics of Cranial Cruciate Ligament Reconstruction in the Dog II. Mechanical Properties

A biomechanical analysis of the results of an over-the-top procedure for replacement of the cranial cruciate ligament (CCL) in the dog is presented. Using 15 adult mongrel dogs, the CCL in one stifle joint was reconstructed using fascia lata and the lateral one-third of the patellar ligament. The opposite CCL served as the control. Animals were sacrificed at 0, 4, 12 and 26 weeks postoperation and axial failure tests were performed. Stiffness, maximum load, and elastic modulus of the replacement increased over time, while elongation to maximum load continually decreased as compared to controls. Other parameters showed less consistent trends.
The results are encouraging given the reduction in joint laxity and the increases in tissue stiffness and strength. However, the ligament substitute was still unable to replicate the mechanical properties of the normal cruciate ligament. Longer studies therefore are required to determine if this replacement is capable of completely restoring joint stability and normal function.     

The Immediate Effect of Colposuspension on Resting and Stressed Urethral Pressure Profiles in Anaesthetized Incontinent Bitches

The aim of this study was to document what changes in the resting and stressed urethral pressure profile occur in the incontinent bitch with urethral sphincter mechanism incompetence (SMI) immediately after colposuspension. Resting and stressed subtracted simultaneous urethral pressure profilometry was performed immediately pre- and postcolposuspension in 26 bitches diagnosed with SMI. All of the urethral pressure profiles were measured in anaesthetized bitches using a standard technique and two orientations of the catheter transducers (dorsal and left). Readable pre- and postoperative urethral pressure profiles were obtained in 20 of the 26 bitches. Subjective and objective evaluation of the profiles showed significant differences in the profiles pre- and postcolposuspension. Immediately postoperatively there were significant ( P < .05) increases in functional profile length, maximum urethral closure pressure (MUCP), and distance between the bladder neck and the first negative respiratory peak and stressed spike. There was a significant ( P < .001) decrease in the percentage of negative spikes extending below the resting intravesical pressure on the subtracted profile. The pressure transmission profiles were significantly ( P < .001) altered by surgery. The findings presented support the hypothesis that colposuspension may restore continence by increasing pressure transmission to the proximal urethra and bladder neck. The results also suggest that immediately after surgery functional urethral length and urethral resistance are increased.