Studies of Colletotrichum gloeosporioides disease on yam, Dioscorea alata, in Solomon Islands

A detailed account of symptoms produced by Colletotrichum gloeosporioides on susceptible and resistant cultivars of yam ( Dioscorea alata ) in Solomon Islands is given. A superficial blackening of upper leaf surfaces of some cultivars is unusual and worthy of further study. In pathogenicity tests with isolates of C. gloeosporioides from various sources, those that were virulent on D. alata were all from D. alata except one from D. esculenta and one from Cucumis sativus but only nine of 30 isolates from D. alata were virulent on this host. Since all four isolates of the yam pathogen tested on D. nummularia and D. trifida were virulent, it is inappropriate to retain the epiphet f. sp. alatae proposed by earlier authors. Considerable variation in cultural morphology existed among virulent isolates, the only consistent character being production of dark pigment, although this was also produced by some saprophytic isolates. Most reisolations of C. gloeosporioides from lesions resulting from inoculation yielded isolates identical with the original inoculum but also some reisolates had a different morphology.     

Clinical Use of Recombinant Human Bone Morphogenic Protein-2 in a Whooping Crane (Grus americana)

Objective— To report use of recombinant human bone morphogenetic protein-2 (rhBMP-2) as adjunctive therapy for treatment of a comminuted, open, proximal humeral fracture in an avian species.
Study Design— Clinical report.
Animals— A 3.5-month-old male whooping crane ( Grus americana ).
Methods— An open, severely comminuted humeral facture was stabilized with an intramuscular (IM) pin/type IA external skeletal fixator with tie-in configuration. rhBMP-2 was applied in a calcium phosphate matrix (CPM) paste directly to the fracture site as a bone graft substitute. Radiographic evidence of bone healing was monitored for 14 weeks.
Results— Substantial bony callus was evident at 4 weeks and at 8 weeks there was bridging callus with obvious bony remodeling. The fixation was destabilized at 9 weeks by IM pin removal, bone healing progressed and the fixator was removed at 11 weeks. By 14 weeks both cortices had been re-established with continued callus remodeling evident.
Conclusion— rhBMP-2, applied in a CPM paste, was used as a bone graft substitute in the treatment of a comminuted, open humeral fracture in a whooping crane.
Clinical Relevance— Use of rhBMP-2/CPM should be considered in treatment of avian fractures.     

Triadimenol drenches and residues in tobacco seedbeds improve growth and disease control in transplants

Triadimenol residues in sandy and clay soils, following applications of up to 1 g/m² in previous seasons to tobacco seedlings 2 days before they were transplanted, had little effect on seedling emergence and growth. Residues were beneficial to transplants; they improved growth and controlled stem and root infection caused by Rhizoctonia solani and Fusarium solani. During the first 4 weeks after transplanting, stem infection was negatively correlated with log_e of the pre-sowing rate of triadimenol and with log_e of the soil concentration in seedbeds at pulling. Plant growth increased linearly according to the equation l/Y=a+b/(x-c), where Y = plant dry mass (g/plant), .x = triadimenol pre-sowing (mg/m²) and c= - 1 1, determined iteratively, r² = 0-94; P < 0.001. Triadimenol applications to bare soil increased the soil concentration by 1 μ/g per 50 mg/m² applied.     

Seasonal home range estimates and habitat selection of saugeye in a small warmwater impoundment

Abstract Saugeye, a hatchery‐produced hybrid of walleye, Sander vitreus (Mitchill), × sauger, Sander canadense (Griffith & Smith), is commonly stocked by several state fishery management agencies in the United States. Saugeye is a top‐level predator that can restructure fish communities and provide supplemental angling opportunities. However, there are few published studies explaining distributions and habitat selection of saugeye. This study determined seasonal home range estimates and habitat selection of saugeye in a small warmwater impoundment using ultrasonic telemetry. Seasons for this study were defined as winter, spawn, spring, summer and autumn. Mean home range estimates were greatest during spawn when water temperature increased from 7.5 to 15 °C and lowest in winter when water temperature decreased below 7.5 °C. Saugeye selected open water and mid‐water ledge habitat during each season, but rock/gravel shoreline was increasingly selected during winter and spawn. These results corroborate previous studies that suggest saugeye exhibit seasonal variation in distribution and habitat use patterns. Managers should consider distribution and habitat selection trends of saugeye when assessing stocks or determining whether to introduce the species in a small warmwater impoundment.     

Environmental conditions, satellite imagery, and clupeoid recruitment in the northern Benguela upwelling system

The relationship between oceanographic conditions and clupeoid (pilchard, Sardinops sagax, and anchovy, Engraulis capensis ) recruitment in the northern Benguela upwelling system was investigated from 1981 to 1987 using a time-series of mean weekly SST images. Two approaches were taken. The first involved correlating recruitment success with the number of weekly coastal `SST events' above various cut-off temperatures during the main reproductive season. The second involved constructing a multiple regression model of recruitment success with two independent environmental variables: namely, the number of coastal `SST events' greater than 19°C, and an onshore retention index for the early life-history stages. The retention index was derived from a spatial time-series analysis of the SST images using principal components analysis. In general, pilchard recruitment showed a positive relationship with the `number of SST events' whilst anchovy recruitment had a negative relationship; 1987 was an outlier year, during which there were exceptionally high levels of both pilchard and anchovy recruitment. The multiple regression R ² values were high and significant for both species (pilchard R ² = 0.88, anchovy R ² = 0.96). The regression model also accounted for the 1987 outlier according to levels of onshore retention which, despite low inshore SSTs, were particularly high during the 1986/87 reproductive season. Although these results need to be validated with data from a longer time period, they show how satellite data might be used for predicting clupeoid recruitment success in the northern Benguela.