The cause of deep-pitted scab of potatoes

By use of a tyrosine-casinate-nitrate medium,Streptomyces atroolivaceous, S. cinerochromogenes, S. corchorusii, S. diastatochromogenes, S. lydicus, S. malachiticus, and three unidentifiedStreptomyces spp. were isolated from deep-pitted scab lesions on potato cultivars Green Mountain, Red Pontiac, Russet Burbank, and Saco. Over 90% of the deep-pitted lesions contained one or more of theseStreptomyces spp., butS. scabies the cause of shallow scab was not isolated. Isolates ofStreptomyces spp. were also consistently isolated from aseptically excised non-necrotic tissue near the edge of lesions. TheseStreptomyces spp. appeared to be the primary colonizers of this tissue. Alternaria spp.,Fusarium spp.,Penicillium spp.,Rhizopus spp.,Trichoderma spp., and several unidentified non-sporulating fungi as well asBacillus spp.,Pseudomonas spp., andMicrococcus spp. were isolated from deep-pitted scab lesions. Fungal and bacterial isolates varied from one scab lesion to another and except for anAlternaria sp., were not pathogenic. Most of theStreptomyces spp. isolates used to infest heat pasteurized field soil caused deep and/or shallow scab on tubers of the potato cultivar Kennebec in greenhouse and outdoor plantings. Re-isolations from resulting scab lesions yieldedStreptomyces spp. similar in morphology to those used as inoculum. We concluded that a number ofStreptomyces spp. probably includingS. scabies (ATCC 3352 = S.griseus) may cause deep and shallow scab.     

Aircraft-applied sulfur for control of powdery mildew (erysiphe cichoracearum) on potato in washington state

Aircraft-applied dust and liquid sulfur sprays were evaluated for control of powdery mildew (Erysiphe cichmacearumDC), on rill irrigated potatoes (cv. Russet Burbank). Either form of sulfur applied weekly or biweekly usually controlledE. chichoracearum through September, but not in October. Significant yield increases were obtained in only two of five trials. The small differences in disease severity between weekly and biweekly applications of sulfur were not significant. Sulfur gave very little control if applied after infection was established. Applications of liquid sulfur, the formulation less likely to cause environmental problems, should be started at the first trace of stipples on stems and continued biweekly throughout the season.     

Designing a transfrontier conservation landscape for the Maputaland centre of endemism using biodiversity, economic and threat data

A number of global priority region schemes have been developed, but local assessments are needed to identify priority areas for conservation within these regions. Here, we describe results from a conservation assessment for Maputaland, part of a biodiversity hotspot in southern Africa that is also the focus of the Lubombo Transfrontier Conservation Area (TFCA) initiative between South Africa, Mozambique and Swaziland. The TFCA seeks to establish new state-, private- and communally-managed conservation areas to boost economic development through nature-based tourism and game ranching. The assessment will guide the TFCA process and used a systematic conservation planning approach to design a landscape to conserve 44 landcover types, 53 species and 14 ecological processes. The assessment also included data on modelled risk of agricultural transformation, of which low-risk areas were selected where possible. The current PA systems in the three countries cover 3830 km², which represents 21.2% of the region, and meet the representation targets for 46% of the conservation features. The proposed conservation landscape adds 4291 km² of new core areas and 480 km² of linkages and, if appropriate, could provide potential revenues of US$18.8 million from game ranching, based on modelled large ungulate density, life history and game auction data. We also discuss the benefits of including data on widely distributed, better known conservation features together with less-well studied, range-restricted species and the advantages of using agricultural transformation risk data in conservation assessments.     

Evaluation of increased subchondral bone density in areas of contact in the metacarpophalangeal joint during joint loading in horses

OBJECTIVE: To quantitatively evaluate contact area under 2 loads and subjectively compare contact areas with subchondral bone (SCB) density patterns in intact metacarpophalangeal joints of horses. SAMPLE POPULATION: 6 forelimbs from horses without musculoskeletal disease. PROCEDURES: Computed tomographic scans of intact metacarpophalangeal joints were analyzed to obtain SCB density measurements. Each limb was loaded on a materials testing system to 150 degrees and 120 degrees extension in the metacarpophalangeal joint, and the joint was stained via intra-articular injection with safranin-O or toluidine blue, respectively. Each joint was disarticulated, and the surface area was digitized. Total articular surface area, contact area, and percentage contact area at each angle were calculated for the distal third metacarpal condyles, the proximal phalanx, and the proximal sesamoid bones. RESULTS: Contact area on the third metacarpal condyles, proximal sesamoid bones, and the proximal phalanx significantly increased with increased load. Areas of contact subjectively appeared to have a higher density on computed tomographic scans. CONCLUSIONS AND CLINICAL RELEVANCE: Areas consistently in contact under higher load were associated with increased SCB density. This supports the idea that the SCB adapts to the load applied to it. As load increased, contact area also increased, suggesting that areas not normally loaded may have a high degree of stress during impact loading. Quantifying how contact in the joint changes under different loading conditions and the adaptation of the bone to this change in normal and abnormal joints may provide insight into the pathogenesis of osteochondral disease.     

Spatial and seasonal differences in the top predators of Easter Island: Essential data for implementing the new Rapa Nui multiple‐uses marine protected area

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Seed yield in perennial ryegrass (<Emphasis Type="Italic">Lolium perenne</Emphasis> L.): comparative importance of component traits and detection of seed-yield-related QTL

The aims of our study were to evaluate relationships amongst morphological traits associated with seed production in a perennial ryegrass biparental population and to identify genomic regions associated with phenotypic variation in those traits using QTL analysis. This was achieved using data from two field experiments at Palmerston North and Lincoln, New Zealand, in 2003, and days to heading (DTH), reassessed in 2004. Trait association was determined for the Palmerston North experiment where measured traits included seed yield per plant (SYPlant), seed yield per spike (SYSp), reproductive tiller number (RTiller), spikelets per spike (SpktSp), florets per spikelet (FSpkt), 1000 seed weight (TSW), spike length (SpLen), florets per spike (FSp), floret site utilization (FSUtil), spread of heading (SOH) and plant growth habit (PGHabit). Traits contributing to SYPlant in order of descending value were FSpkt, FSUtil, and RTiller. High TSW was only weakly linked to SYPlant. FSUtil, SOH and RTiller were identified as valuable breeding targets for improving seed yield potential in perennial ryegrass. QTL were identified for all traits except for RTiller. QTL for SYPlant occurred on linkage groups (LG) 2 and 6. Both were co-located with QTL for SYSp and sets of SYPlant components or related traits (FSpkt, FSp; FSUtil and TSW). Major QTL for DTH were identified on LG2 and LG4 and minor QTL on LG7 in consecutive years. There was a strong genotype-by-environment interaction for SYPlant that was reflected in a lack of consistent QTL across environments, while QTL for SYSp and DTH were stable across environments. Identification of component traits and QTL important for seed yield may accelerate genetic improvement in perennial ryegrass through conventional and marker-assisted breeding, respectively.     

Early effects of COVID‐19 on US fisheries and seafood consumption

The US seafood sector is susceptible to shocks, both because of the seasonal nature of many of its domestic fisheries and its global position as a top importer and exporter of seafood. However, many data sets that could inform science and policy during an emerging event do not exist or are only released months or years later. Here, we synthesize multiple data sources from across the seafood supply chain, including unconventional real‐time data sets, to show the relative initial responses and indicators of recovery during the COVID‐19 pandemic. We synthesized news articles from January to September 2020 that reported effects of COVID‐19 on the US seafood sector, including processor closures, shortened fishing seasons and loss of revenue. Concerning production and distribution, we assessed past and present landings and trade data and found substantial declines in fresh seafood catches (?40%), imports (?37%) and exports (?43%) relative to the previous year, while frozen seafood products were generally less affected. Google search trends and seafood market foot traffic data suggest consumer demand for seafood from restaurants dropped by upwards of 70% during lockdowns, with recovery varying by state. However, these declines were partially offset by an increase (270%) in delivery and takeout service searches. Our synthesis of open‐access data sets and media reports shows widespread, but heterogeneous, ramifications of COVID‐19 across the seafood sector, implying that policymakers should focus support on states and sub‐sectors most affected by the pandemic: fishery‐dependent communities, processors, and fisheries and aquaculture that focus on fresh products.     

Pyrethroid resistance mechanisms in Australian Helicoverpa armigera

In 1983, at the onset of pyrethroid resistance in Australian Helicoverpa armigera, three resistance mechanisms were identified. They were: a strong nerve insensitivity (Super-Kdr), penetration resistance (Pen), and a factor which was overcome by piperonyl butoxide (PBO). Super-Kdr nerve insensitivity appeared to be a major cause of pyrethroid resistance and contributed to high-order resistance (> 100-fold). From 1987 to 1990, to monitor the effect of the Australian Helicoverpa insecticide resistance management strategy on insecticide resistance, we conducted a survey of the frequencies of these mechanisms in field-collected H. armigera. The relative importance of the Pen and Pbo mechanisms in resistant H. armigera have increased but Pen and Pbo confer only low order (～ 20-fold) resistance. We found no evidence of the 1983 Super-Kdr mechanism in the latest samples, but, instead, found another distinct Kdr-type mechanism. This mechanism was correlated with very low-order nerve insensitivity and was of little toxicological significance. The impact of the Helicoverpa insecticide resistance management strategy on pyrethroid resistance in H. armigera is discussed.