Comparison between the penetration characteristics of methyl bromide and ethanedinitrile through the bark of pine (Pinus radiata D.Don) logs

BACKGROUND

Ethanedinitrile (EDN) is a fumigant being commercialized worldwide as an alternative phytosanitary treatment to methyl bromide (MB) for forest products. The penetration characteristics of MB and EDN were measured through the bark of wooden blocks (100 × 100 × 50 mm) cut from the upper (average bark thickness 5 ± 2 mm) and lower (average bark thickness 25 ± 5 mm) trunk of recently felled pine (Pinus radiata D.Don) trees. Doses of 48 g m⁻³ MB and 50 g m⁻³ EDN were applied to chambers at 10 and 20°C for 10 h.

RESULTS

Penetration of MB was influenced by the interaction between fumigation time and temperature, with concentrations increasing at a higher rate at 20°C compared with at 10°C. After 10 h, an average concentration of 8.05 ± 0.89 g m⁻³ had penetrated the bark of log sections at 20°C, whereas 5.20 ± 0.89 g m⁻³ was measured at 10°C. By contrast, the factors examined in this study did not significantly impact the penetration of EDN. Concentration × time (CT) values for MB under the bark were 35.20 ± 2.30 g h m⁻³ at 10°C and 55.85 ± 9.58 g h m⁻³ at 20°C; whereas for EDN, CT values were 19.50 ± 6.80 g h m⁻³ at 10°C and 19.08 ± 4.10 g h m⁻³ at 20°C.

CONCLUSION

MB can achieve a higher concentration under the bark of log sections during simulated fumigations, but all of the factors examined affected the ability of MB to penetrate the bark of wooden blocks. By comparison, the penetration of EDN through the bark is more consistent than MB under laboratory conditions. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Pilot study of the ultrasonographic examination of the intact and transected medial glenohumeral ligament in dogs

Medial glenohumeral ligament injury is commonly reported during medial shoulder joint instability in dogs. Arthroscopy is considered the gold standard procedure, but it is invasive and requires distension of the joint. Ultrasonographic examination of the medial glenohumeral ligament has been studied as a possible, less invasive alternative to arthroscopy however it has not been considered a useful method of assessment due to the interference of the probe with the pectoral muscles. The aims of this prospective analytical randomized pilot study were to develop a standardized ultrasound protocol for visualizing the canine medial glenohumeral ligament and to compare goniometry and ultrasound findings in cadaver dogs with versus without transection of the medial glenohumeral ligament. Nine adult Beagle cadavers (18 shoulders) were used. The first six shoulders were used in a preliminary study to describe an ultrasound technique to identify the medial glenohumeral ligament. Arthroscopy was performed on the remaining 12 shoulders, with six randomly selected medial glenohumeral ligaments from these shoulders, transected during the procedure. Ultrasound examination was performed after each arthroscopic procedure by an ultrasonographer blinded to the patient group. Four medial glenohumeral ligaments (67%) were correctly identified during the preliminary study. Ultrasonographic examination failed to diagnose the transection of all six medial glenohumeral ligaments in the second part of the study. No difference was observed in the ligament thickness between the dogs with and without a transected medial glenohumeral ligament. Dogs with a transected medial glenohumeral ligament had a wider articular space compared to dogs without a transected ligament (P < 0.001), and an articular space wider than 8.2 mm was discriminatory of a transected medial glenohumeral ligament in all the shoulders. In conclusion, the medial glenohumeral ligament could be identified with a medial ultrasonographic approach of the shoulder and a wider articular space can be a sign of a medial shoulder joint instability. Further studies are needed to confirm these preliminary findings in living dogs, with and without shoulder instability.     

Farmers' Attitudes to the Benefits and Barriers of Adopting Automation for Surface Irrigation on Dairy Farms in Australia

The study reports farmers' attitudes andperceptions towards the ``barriers' and ``benefits' of automaticirrigation systems. Factor analysis was used to identify perceived ``barriers' and ``benefits' andthe impact of these on farmers' priority to adopt automation wasexamined. Results suggest that farmers'attitudes, particularly with respect to ``cost' and``lifestyle' influenced the priority given to adopting automaticirrigation systems. The area under pasturecultivation was also an importantdeterminant in the farmers' priority foradopting automatic irrigation systems.     

Drivers of recent forest cover change in southern South America are linked to climate and CO2

Landscape Ecology - Widespread changes in forest structure&nbsp;and distribution have been documented in northern Patagonia over the past century. We employed LPJ-GUESS, a dynamic global...     

Induction and Transfer of Enhanced Biodegradation of the Herbicide Napropamide in Soils

In laboratory incubations, the times to 50% loss (DT₅₀) of a first application of napropamide were approximately 25, 45 and 75 days in soil incubated at 25, 15 and 5°C respectively. When treated for a second time, the DT₅₀ values were 4, 7 and 15 days at the same temperatures, irrespective of the temperature of the first incubation. This indicates that enhanced degradation of napropamide in soil can be both induced and expressed at low temperature. A mixed microbial culture able to degrade the herbicide to a single degradation product, identified by HPLC retention time as naphthoxypropionic acid, was obtained from a soil capable of rapid degradation. Addition of a sub-sample of this mixed culture to a previously untreated soil introduced rapid degrading ability. When small amounts of soil capable of rapid degradation were added to previously untreated soil, in both the laboratory and the field, the degradation rate of napropamide increased compared with that in unamended soils.     

Detection of target spot and bacterial spot diseases in tomato using UAV-based and benchtop-based hyperspectral imaging techniques

Early and accurate diagnosis is a critical first step in mitigating losses caused by plant diseases. An incorrect diagnosis can lead to improper management decisions, such as selection of the wrong chemical application that could potentially result in further reduced crop health and yield. In tomato, initial disease symptoms may be similar even if caused by different pathogens, for example early lesions of target spot (TS) caused by the fungus Corynespora cassicola and bacterial spot (BS) caused by Xanthomonas perforans. In this study, hyperspectral imaging (380–1020 nm) was utilized in laboratory and field (collected by an unmanned aerial vehicle; UAV) settings to detect both diseases. Tomato leaves were classified into four categories: healthy, asymptomatic, early and late disease development stages. Thirty-five spectral vegetation indices (VIs) were calculated to select an optimum set of indices for disease detection and identification. Two classification methods were utilized: (i) multilayer perceptron neural network (MLP), and (ii) stepwise discriminant analysis (STDA). Best wavebands selection was considered in blue (408–420 nm), red (630–650 nm) and red edge (730–750 nm). The most significant VIs that could distinguish between healthy leaves and diseased leaves were the photochemical reflectance index (PRI) for both diseases, the normalized difference vegetation index (NDVI850) for BS in all stages, and the triangular vegetation index (TVI), NDVI850 and chlorophyll index green (Chl green) for TS asymptomatic, TS early and TS late disease stage respectively. The MLP classification method had an accuracy of 99%, for both BS and TS, under field (UAV-based) and laboratory conditions.

     

Grass mixtures for afforested opencast spoils in South Wales

An experiment that investigated the establishment of seven grass and legume seed mixes on opencast coal mining spoil in South Wales is described. After three years, mixtures containing Poa pratensis and Festuca rubra var. rubra were the most successful in covering the spoil; the ‘Johnson JR33’ seed mix proved the best of those commercially available that was tested. Tree growth was not detrimentally affected by the establishment of a grass ground cover. Erosion was not an important process at the experimental site, though slumping occurred locally from plough ridge to plough furrow.     

Fish assemblages in the Southern California Current: relationships with climate, 1951–2008

We examined the dominant patterns of variability in the fish fauna of the southern California Current based on a principal component (PC) analysis of the California Cooperative Oceanic Fisheries Investigations ichthyoplankton data set, 1951–2008. Eighty‐six taxa were analyzed, including all ecologically dominant fish species, both exploited and unexploited. The first three PCs accounted for 20.5, 12.4 and 6.8% of the variance of the data, respectively (total: 39.7%). Each was dominated by taxa from particular adult or larval habitats. PC 1 predominantly represented the coherent response of 24 mesopelagic taxa from 10 families and was most highly correlated with long‐term trends in midwater oxygen levels. PC 2 was dominated by six of the seven most abundant ichthyoplankton taxa in the region, predominantly California Current endemics including key pelagic species (northern anchovy, Pacific sardine and Pacific hake), rockfishes (genus Sebastes) and two midwater taxa. It was correlated primarily with sea surface temperature and exhibited a significant declining trend. PC 3 was dominated by coastal and reef‐associated fishes with predominantly southerly affinities. It was positively correlated with sea surface temperature and sea level height, a proxy for diminished flow of the California Current. The taxa dominating PCs 2 and 3 mostly spatially co‐occur as ichthyoplankton. These results suggest that fish assemblages in the California Current are predominantly influenced by environmental forcing of their ocean habitats as adults or larvae, or both.     

Growth and mortality of sibling triploid and diploid Sydney rock oysters, Saccostrea glomerata (Gould), in the Camden Haven River

Growth and mortality of sibling triploid and diploid Sydney rock oysters, grown at two tidal heights, three stocking densities and three different sites on the Camden Haven River estuary, were compared. Triploids grew faster than diploids. The majority of the growth rate difference occurred after the oysters reached 2 years of age. By 3.2 years, triploids were 49% heavier than diploids. Oysters grown intertidally were larger than those grown subtidally. Oysters stocked at the lightest density of 2 L per basket grew to a significantly larger size than baskets stocked at 3 or 4 L. Growth rates were significantly different at the three sites. Growth was reduced the further the oysters were from the mouth of the estuary. There was no significant difference in mortality between ploidy level, but there were differences between tidal heights, stocking densities and sites. Intertidal oysters suffered higher mortality than subtidal. Oysters stocked at the highest density had a significantly higher mortality than the lowest density; neither of these was significantly different from the medium density. The site closest to the mouth of the estuary had significantly lower mortality than the middle and upper estuary sites.