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Since its domestication about a century ago in North America, highbush blueberry (Vaccinium corymbosum L.) has gained appreciation by consumers worldwide, and the demand for new blueberry varieties is increasing. Whole-genome resequencing can help plant breeders to decrease the time needed to create novel varieties by identifying novel genes linked to fruit-quality traits. The present study analyzed the genetic variability of eight V. corymbosum genotypes, seven Romanian varieties ('Prod', 'Vital', 'Azur', 'Simultan', 'Delicia', 'Compact', and 'Safir'), and the American variety, 'Bluecrop'. The analysis of the first ~10 Mb from scaffold 22, a hotspot of genomic variation, in the above-mentioned varieties revealed multiple differences in 11 upregulated and 50 downregulated genes involved in fruit growth and development. Of these differentially regulated genes, two upregulated and five downregulated genes were fully covered by at least 1× coverage depth by sequencing. The genes' sequence analysis confirmed the high genetic variability of the region, with most of the genes presenting numerous SNPs and some InDels, and indicated that an attempted 10× medium-coverage depth of sequencing for V. corymbosum varieties yields useful preliminary data for use in breeding programs. [ABSTRACT FROM AUTHOR]

Highbush blueberry production has expanded worldwide in recent decades. To safeguard future yields, it is essential to understand if insect pollination is limiting current blueberry production and which insects contribute to pollination in different production regions.We present a systematic review including a set of meta‐analyses on insect‐mediated pollination in highbush blueberry. We summarize the geographic distribution of research, the abundance of different pollinator taxa and their relative pollination contributions. Using raw data from 21 studies, totalling 496 site replicates, we determine the degree of pollination service and pollen limitation (i.e. combining open pollination levels with experimental bagged and/or hand pollination treatments), as well as the contribution of honeybees and wild bees to pollination (i.e. observational, open pollination).Most studies originate from North America, focusing on only a few cultivars. Honeybees are the dominant pollinator, and wild bees are occasionally abundant. Wild bees are more efficient pollinators on a single‐visit basis compared to honeybees, which increases their relative pollination contribution compared to their relative abundance.Insect‐mediated pollination services increased blueberry fruit set, berry weight and seed set (R2 values: 64.8%, 75.9% and 75.2% respectively). We often detected pollen limitation, indicated by an increase in fruit set, berry weight and seed set (R2: 10.1%, 18.2% and 21.5%, respectively), with additional hand pollination. Increasing visitation of honeybees and wild bees contributed to blueberry pollination by increasing fruit set (R2: 5.4% and 3.5%), berry weight (R2: 6.5% and 2.8%) and seed set (R2: 6.4% and 3.8%) respectively. Bee contributions to fruit set and berry weight were variable across regions.Synthesis and application: A diverse community of insects, primarily bees, contributes to highbush blueberry pollination and yield. However, pollination deficits are common. The finding that both honeybees and wild bees enhance pollination highlights the possibility of adopting different management strategies that utilize honeybees, wild bees or both depending on the specific context and region. This further emphasizes the general importance of conserving pollinator health and diversity. Our synthesis highlights data gaps and areas for future research to better understand the pollination contribution of different pollinators to crops that are expanding globally. [ABSTRACT FROM AUTHOR]

European foulbrood (EFB) is a severe disease of honey bee (Apis mellifera) larvae caused by the bacterium Linnaeus [Hymenoptera: Apidae]) Melissococcus plutonius (ex White) Bailey and Collins (Lactobacillales: Enterococcaceae). Many beekeepers in North America report severe EFB following blueberry pollination, but it is not clear what factors during pollination are related to clinical disease. Additionally, the impact that other factors such as viral load and hygienic behavior have on EFB has not been studied. In Spring of 2020 we enrolled 60 commercial honey bee colonies in a prospective cohort study. Colonies were inspected 3 times over the season with hive metrics and samples taken for viral testing. Each colony was tested for hygienic behavior twice and the score was averaged. Viral loads were determined by qPCR for deformed wing virus (DWV) A and B. We found no statistical difference in the EFB prevalence or severity between the 2 yards at any timepoint; 50% (n  = 16) of the colonies in the holding yard and 63% (n  = 17) in blueberry developed moderate to severe EFB over the study period. When colonies from both yards were pooled, we found no relationship between viral load or hygienic behavior and development of EFB. These results suggest that other factors may be responsible for driving EFB virulence and hygienic behavior is not likely helpful in managing this disease. [ABSTRACT FROM AUTHOR]

Premise: The true blueberries (Vaccinium sect. Cyanococcus; Ericaceae), endemic to North America, have been intensively studied for over a century. However, with species estimates ranging from nine to 24 and much confusion regarding species boundaries, this ecologically and economically valuable group remains inadequately understood at a basic evolutionary and taxonomic level. As a first step toward understanding the evolutionary history and taxonomy of this species complex, we present the first phylogenomic hypothesis of the known diploid blueberries. Methods: We used flow cytometry to verify the ploidy of putative diploid taxa and a target‐enrichment approach to obtain a genomic data set for phylogenetic analyses. Results: Despite evidence of gene flow, we found that a primary phylogenetic signal is present. Monophyly for all morphospecies was recovered, with two notable exceptions: one sample of V. boreale was consistently nested in the V. myrtilloides clade and V. caesariense was nested in the V. fuscatum clade. One diploid taxon, Vaccinium pallidum, is implicated as having a homoploid hybrid origin. Conclusions: This foundational study represents the first attempt to elucidate evolutionary relationships of the true blueberries of North America with a phylogenomic approach and sets the stage for multiple avenues of future study such as a taxonomic revision of the group, the verification of a homoploid hybrid taxon, and the study of polyploid lineages within the context of a diploid phylogeny. [ABSTRACT FROM AUTHOR]

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The true blueberries (Vaccinium sect. Cyanococcus; Ericaceae) comprise a clade of about nine to 24 species distributed mainly in eastern temperate North America, with one species reaching farther west. Despite extensive study, the systematics and evolution of the group are still poorly understood. Limited morphological variation, multiple ploidy levels of uncertain origin, and natural hybridization all contribute to the challenge. Questionable analytical methods, such as the use of phenetics and an overemphasis on crossing experiments, have further impeded progress. Here we review the history of research on the systematics and evolution of V. sect. Cyanococcus with the aim of clarifying and summarizing hypotheses of species origins and diversification, especially in relation to polyploidy. We also present recent progress from our own work and, on that basis, offer promising lines of investigation with morphological and molecular data. We anticipate that these avenues of research will ultimately clarify patterns of natural species diversity in V. sect. Cyanococcus with benefits for biodiversity studies, conservation, and crop breeding. [ABSTRACT FROM AUTHOR]

Mummy berry disease, caused by the fungal pathogen Monilinia vaccinii-corymbosi (Mvc), is one of the most economically important diseases of blueberries in North America. Mvc is capable of inducing two separate blighting stages during its life cycle. Infected fruits are rendered mummified and unmarketable. Genomic data for this pathogen is lacking, but could be useful in understanding the reproductive biology of Mvc and the mechanisms it deploys to facilitate host infection. In this study, PacBio sequencing and Hi-C interaction data were utilized to create a chromosome-scale reference genome for Mvc. The genome comprises nine chromosomes with a total length of 30Mb, an N50 length of 4.06Mb, and an average 413X sequence coverage. A total of 9399 gene models were predicted and annotated, and BUSCO analysis revealed that 98% of 1,438 searched conserved eukaryotic genes were present in the predicted gene set. Potential effectors were identified, and the mating-type (MAT) locus was characterized. Biotrophic effectors allow the pathogen to avoid recognition by the host plant and evade or mitigate host defense responses during the early stages of fruit infection. Following locule colonization, necrotizing effectors promote the mummification of host tissues. Potential biotrophic effectors utilized by Mvc include chorismate mutase for reducing host salicylate and necrotrophic effectors include necrosis-inducing proteins and hydrolytic enzymes for macerating host tissue. The MAT locus sequences indicate the potential for homothallism in the reference genome, but a deletion allele of the MAT locus, characterized in a second isolate, indicates heterothallism. Further research is needed to verify the roles of individual effectors in virulence and to determine the role of the MAT locus in outcrossing and population genotypic diversity [ABSTRACT FROM AUTHOR]

Plants are inhabited by millions of parasitic, commensal, and mutualistic microorganisms that coexist in complex ecological communities, and profoundly affect the plant's productivity, health, and capacity to cope with environmental stress. Therefore, a better understanding of the rhizosphere microbiome may open a yet untapped avenue for the rational exploitation of beneficial plant–microbe interactions in modern agriculture. Blueberries encompass several wild and cultivated species of shrubs of the genus Vaccinium that are native to North America. They are grown commercially for the production of fruits, which are considered a health food due to the rich content of minerals, trace elements, and phenolic compounds with antioxidant, antitumor, and anti-inflammatory properties. Despite a long history of breeding and extensive commercial use, remarkably little is known about the composition and function of the blueberry root microbiome. To address this gap, we employed molecular approaches to characterize and compare microbial communities inhabiting the roots of rabbiteye blueberry (Vaccinium virgatum), Darrow's blueberry (Vaccinium darrowii), and southern highbush blueberry (SHB; an interspecific hybrid of Vaccinium corymbosum and V. darrowii). Our results revealed that these plant species share a common core rhizobiome, but at the same time differ significantly in the diversity, relative abundance, richness, and evenness of multiple groups of prokaryotic and eukaryotic microorganisms. Although the host signature effects were especially pronounced at the plant species level, we also observed genotype-level variations in the distribution of specific microbial taxa, which suggests that the assembly of the blueberry microbiome is shaped by the plant genotype and modifications associated with the domestication and breeding of members of the Vaccinium genus. We also demonstrated that the studied Vaccinium species differ in the abundance of beneficial rhizobacteria and ericoid mycorrhizal fungi, which play a vital role in their adaptation to soils with low pH and slow turnover of organic matter. [ABSTRACT FROM AUTHOR]

Damage by the blueberry gall midge Dasineura oxycoccana (Johnson) (Diptera: Cecidomyiidae) was found on different cultivars of highbush Vaccinium corymbosum L. at different localities of Lithuania. D. oxycoccana is a serious insect pest of blueberries in North America. In 1996, unusual damage on blueberries was observed in Europe. This is the first report of the blueberry gall midge occurrence in blueberry plantations in Lithuania. [ABSTRACT FROM AUTHOR]

Despite the tenebrionid genus Blapstinus being species rich with 91 described species in North America, individual beetles are not commonly observed. We collected Blapstinus metallicus (Fab.) in Maine wild blueberry fields in 2012 and in a Massachusetts wooded residential property in 2017. This species has the largest geographic range of all the Blapstinus species reported in North America. Our paper reports on the death feigning behavior of B. metallicus and provides a review of the literature on this little studied group of beetles. [ABSTRACT FROM AUTHOR]

The population structure of blueberry mosaic associated virus (BlMaV), a putative member of the family Ophioviridae , was examined using 61 isolates collected from North America and Slovenia. The studied isolates displayed low diversity in the movement and nucleocapsid proteins and low ratios of non-synonymous to synonymous nucleotide substitutions, indicative of strong purifying selection. Phylogenetic analyses revealed grouping primarily based on geography with some isolates deviating from this rule. Phylogenetic incongruence in the two regions, coupled with detection of reassortment events, indicated the possible role of genetic exchange in the evolution of BlMaV. [ABSTRACT FROM AUTHOR]

The article discusses new records of Andrena is an Holarctic genus with about 500 species in North America and 650-700 species in Eurasia found on all continents except Australia, Antarctica and South America. Topics discussed include information on species of Andrena including Andrena bisalicis, Andrena rugosa and Andrena salictaria; seasonal flowering phenology of seven common native willow species and collection of Andrena bisalicis during the pre- and post-bloom period of blueberry.

Blueberries originated from North America and the predominant cultivated species are Vaccinium corymbosum (Northern and Southern Highbush), Vaccinium ashei (Southern Rabbiteye), and Vaccinium angustifolium (Lowbush). Consumer's demand for high-quality blueberry fruits has driven the interest to better understand the flavor chemistry of blueberry. Forty-five previously identified aroma contributing compounds were further investigated in 11 blueberry varieties, including some developing types. Based on odor activity value, branch-chain esters, terpenes, and aldehydes could be the primary aroma contributors to all 11 blueberry varieties. A heatmap with hierarchical clustering dendrogram showed that the three varieties ORUS 235-4, ORUS 235-3, and ORUS-10-1 were close together with a high level of branch-chain esters and, in turn, close to 'Draper' and 'Duke'. However, they differed from the other varieties, including 'Aurora', 'Bluecrop', 'Elliott', 'Legacy', 'Liberty,' and ORUS-202-2. One-way ANOVA analysis demonstrated that terpenoids varied the most among varieties. Also, the Pearson correlation showed terpenoids, except eucalyptol, exhibited a strong positive correlation, especially between linalool and α-terpineol. Enantiomer analysis revealed S-(+)-linalool was dominant in all blueberries, whereas the S-(−)-α-terpineol was slightly higher than R-(+)-α-terpineol. This study provided a detailed volatile composition database for unraveling the complex genetics of the various blueberry flavor aspects to assist the breeding purposes of new blueberry crops. • Blueberry volatiles analyzed by HS-SPME-GC-MS using isotope internal standards. • S-(+)-linalool was dominant with S-(−)-α-terpineol higher than R-(+)-α-terpineol. • Branch-chain esters, terpenes, and aldehydes were the major aroma contributors. • One-way ANOVA analysis demonstrated terpenoids varied most among cultivars. • The detailed volatile composition can assist the blueberry breeding program. [ABSTRACT FROM AUTHOR]

The factors explaining host-associated differentiation ( HAD) have not yet been fully characterized, especially in agricultural systems. It is thought that certain characteristics within a system may increase the probability for HAD to occur. These characteristics include relatively long-standing evolutionary relationships between insects and their host plants, endophagy, and allochrony in host-plant phenologies. We assessed the status of these characteristics as well as the presence of HAD in the cranberry fruitworm, Acrobasis vaccinii Riley ( Lepidoptera: Pyralidae), a pest associated with blueberry and cranberry in eastern North America. We reveal the occurrence of two distinct populations of A. vaccinii that are allochronically isolated by the phenological stage of their respective host plants (cranberries or blueberries). Laboratory-reared A. vaccinii adults collected from blueberries emerge at least 1 week earlier than adults from cranberries and the antennal sensitivity of adults to host-plant volatiles differs between A. vaccinii collected from blueberry and cranberry. Despite finding characteristics indicative of HAD, we did not detect a genetic signature of HAD in A. vaccinii. These findings suggest that HAD may occur through behavioral and phenological mechanisms before there is sufficient genetic variation to be detected. [ABSTRACT FROM AUTHOR]

Anthracnose fruit rot of blueberries caused by Colletotrichum acutatum is a serious problem in humid blueberry-growing regions of North America. In order to develop a disease prediction model, environmental factors that affect mycelial growth, conidial germination, appressorium formation and fruit infection by C. acutatum were investigated. Variables included temperature, wetness duration, wetness interruption and relative humidity. The optimal temperature for mycelial growth was 26°C, and little or no growth was observed at 5 and 35°C. The development of melanized appressoria was studied on Parafilm-covered glass slides and infection was evaluated in immature and mature blueberry fruits. In all three assays, the optimal temperature for infection was identified as 25°C, and infections increased up to a wetness duration of 48 h. Three-dimensional Gaussian equations were used to assess the effect of temperature and wetness duration on the development of melanized appressoria ( R2 = 0·89) on Parafilm-covered glass slides and on infection incidence in immature ( R2 = 0·86) and mature ( R2 = 0·90) blueberry fruits. Interrupted wetness periods of different durations were investigated and models were fitted to the response of melanized appressoria ( R2 = 0·95) and infection incidence in immature ( R2 = 0·90) and mature ( R2 = 0·78) blueberry fruits. Additionally, the development of melanized appressoria and fruit infection incidence were modelled in relation to relative humidity ( R2 = 0·99 and 0·97, respectively). Three comprehensive equations were then developed that incorporate the aforementioned variables. The results lay the groundwork for a disease prediction model for anthracnose fruit rot in blueberries. [ABSTRACT FROM AUTHOR]

Blueberry and cranberry are fruit crops native to North America and they are well known for containing bioactive compounds that can benefit human health. Cultivation is expanding within North America and other parts of the world raising concern regarding distribution of existing viruses as well as the appearance of new viruses. Many of the known viruses of these crops are latent or asymptomatic in at least some cultivars. Diagnosis and detection procedures are often non-existent or unreliable. Whereas new viruses can move into cultivated fields from the wild, there is also the threat that devastating viruses can move into native stands of Vaccinium spp. or other native plants from cultivated fields. The aim of this paper is to highlight the importance of blueberry and cranberry viruses, focusing not only on those that are new but also those that are emerging as serious threats for production in North America and around the world [ABSTRACT FROM AUTHOR]

Wild blueberry (Vaccinium angustifolium Ait.) is a unique crop native to Northeastern North America with annual production of 82,000t from an area of 79,000ha. Yield maps along with topography and soil nutrient maps could be used to develop precise site-specific nutrition programs for wild blueberry production. Here, the development of an automated yield monitoring and mapping system for real-time fruit yield estimation for wild blueberry is presented. The hardware components of the system consist of a digital colour camera, a positioning system receiver and a computer mounted on a specially designed farm motorised vehicle. The yield prediction method was based on the estimation of the blue pixels representing ripe fruit in the field of view of each image and their expression as a percentage of total image pixels, using it as the correlation parameter with the corresponding yield. The image processing software was development in “Delphi” and “C” programming languages. Field experiments were carried out in two commercial wild blueberry fields. Concerning the calibration of the system, the experimental results show a significant correlation between percentage blue pixels and actual fruit yield (R 2 =0.90; P <0.001). In the validation of the system, the correlation between actual and predicted fruit yield also was highly significant (R 2 =0.97; P <0.001). Furthermore, fruit yield maps showed substantial variation within the field demonstrating the use of the yield mapping system as the basis for the implementation of site-specific management practices within the blueberry fields. [Copyright &y& Elsevier]

Blueberries (Vaccinium spp.) are an important agricultural crop in the Pacific Northwest of the U.S. and coastal British Columbia of Canada. Three separate surveys were conducted to elucidate the occurrence and distribution of plant-parasitic nematodes in the Pacific Northwest and British Columbia. Plant-parasitic nematodes were detected in 73% of the surveyed blueberry fields. The two most commonly encountered plant-parasitic nematodes in all geographical locations surveyed were Paratrichodorus spp. and Pratylenchus spp. Xiphinema americanum was also detected during the surveys, but was geographically limited to southern Washington and the Willamette Valley of western Oregon. Five other plant-parasitic nematode genera/families were detected during the surveys, but never at high frequencies. [ABSTRACT FROM AUTHOR]

The wild blueberry industry of North America may benefit significantly from precision agriculture technology. Currently, crop management practices are implemented on an average basis without considering the substantial variation in soil properties, bare spots, topographic features, and fruit yield in blueberry fields. Yield maps along with fertility, weed, and topographic maps canoe used to generate prescription maps for site-specific application of agrochemicals (e.g., fertilizer or pesticide). Two wild blueberry fields in central Nova Scotia were selected to evaluate a photographic method for fruit yield estimation. A 10-megapixel 24-bit digital color camera was mounted on a tripod and pointed downwards to take photographs of the blueberry crop from a height of approximately 1 m. At harvest time, blueberry crop images were collected in each field at 30 different sample locations displaying a range in yield. Actual fruit yield was sampled from the same locations by hand-harvesting out of a 0 5 x 0.5 m quadrat using a commercial blueberry rake. Custom image processing software was developed to count the blue pixels of ripe fruit in the quadrat region of each image and express it as a percentage of total quadrat pixels. Linear regression was used to calibrate the fruit yield with percentage blue pixels separately in each field, and then the calibration equation of field 1 was used. to predict fruit yield in field 2 for validation of the method. Percentage blue pixels correlated highly significantly with hand-harvested fruit yield in field 1 (R² = 0.98; P < 0.001; n = 30) and field 2 (R² = 0.99; P < 0.001; n =30). The correlation between actual and predicted fruit yield in field 2 (validation) was also highly significant (R² = 0.99; P <0.001; n = 30; RMSE = 277 kg/ha). Non-significance of the t-test for actual versus predicted yield indicated that there was no significant bias in the yield estimation and that the predicted yield was accurate. Based on these results, an automated yield monitoring system consisting of a digital camera, computer, and DGPS will be developed and incorporated into a harvester to monitor and map blueberry fruit yield in real time. [ABSTRACT FROM AUTHOR]

The wild lowbush blueberry (Vaccinium angustifolium Ait.) is an important successional species of cleared woodland and abandoned farmland of northeastern North America where commercial, managed blueberry fields have been developed. Unlike other fruit crops, the weed flora is unique and consists mainly of a broad range of native herbaceous and woody perennial species that thrive under the two-year cropping system. Traditionally, weedy vegetation was controlled or suppressed by burning, cutting, and roguing, and regenerating woody and herbaceous species were the major weed problems. The introduction of phenoxyalkanoic herbicides in the late 1940's lead to the early development by innovative growers of selective roller/wiper applicators that could control the taller, weedy overstory. Several selective preemergence herbicides (terbacil and diuron) were introduced in the 1970's to control grasses and some broadleaved weeds, and hexazinone was approved in Canada in 1982 and in Maine in 1983. This soil-applied, broad spectrum herbicide has controlled many of the common woody and herbaceous weeds. Its widespread use lead rapidly to increased yields and, directly or indirectly, it has contributed to changes in other production practices, such as the further development of mechanical harvesters and increased fertilizer use. However, the almost total reliance on the repeated use of hexazinone has introduced other problems, including shifts in weed species, the development of resistance, and soil degradation on vegetation- free soils. The highly soluble nature of the herbicide has resulted in wide-spread detection of hexazinone in groundwater adjacent to managed blueberry fields. Best Management Practices have been introduced to minimize problems associated with hexazinone use and is leading to new approaches to vegetation management that employ reduced risk herbicides, lower rates, mulches and ground covers. [ABSTRACT FROM PUBLISHER]

This paper, presented as part of a symposium at the 9th North American Blueberry Research and Extension Workers Conference, Halifax, Nova Scotia, Canada, August 18-21, 2002, traces the early history of the wild blueberry (Vaccinium angustifolium, Aiton, and Vaccinium myrtilloides, Michaux) in eastern North America. Wild blueberry production is traced from consumption of native blueberries by animals and native North Americans, through early commercial production in Canada and the United States, up to the present time. Different management methods adopted as the scientific knowledge increased are described. Early management consisted of burning fields one spring and harvesting the fruit in August of the following year. Over the last century, several new practices have been introduced to increase blueberry yields. These include the oil burner, the flail mower, the mechanical harvester, increased use of selective herbicides, increased use of managed pollinators, and extensive land leveling. [ABSTRACT FROM AUTHOR]

Plum curculio, Conotrachelus nenuphar (Herbst), is a quarantine pest of many temperate fruits, such as pomes, Malus spp.; stone fruits, Prunus spp.; and blueberries, Vaccinium spp.; in North America east of the Rocky Mountains and a small area in Utah. There are two strains, a northern univoltine one that undergoes obligate diapause as an adult and a southern multivoltine strain that usually has facultative diapause. Current quarantine treatments for shipment to areas that do not have the pest include methyl bromide fumigation and cold storage for several weeks. The cold storage treatment may not be effective against northern strain adults in diapause. The objective of this research was to develop an irradiation quarantine treatment against plum curculio. The estimated dose to kill southern strain plum curculio adults in one day is ≈ 4 kGy. Diapausing northern strain plum curculios were prevented from reproducing with 40 Gy. Reproduction of southern strain plum curculios was prevented with a target dose of 80 Gy, and the dose recommended as a quarantine treatment, that would prevent adults from reproducing, is 92 Gy, the maximum absorbed dose measured when a target dose of 80 Gy was sought. At that dose, oviposition may still occur for up to 1 wk and some of the eggs may hatch, but there is no development beyond the first instar. Hosts of the plum curculio would tolerate that dose well. Immature plum curculios were prevented from reproducing with lower doses. [ABSTRACT FROM AUTHOR]

Simple Summary: Japanese beetle is a serious pest of many crops, including blueberry. While the adult beetles feed on leaves, the grubs (immatures) feed on plant roots and can cause wilting and reduced plant growth. Farmers rely on insecticides to control Japanese beetle, but nematodes that attack and kill grubs in the soil may be as effective as insecticides in some cases. Mulches of compost, woodchips, sawdust, and tree bark are commonly used in blueberry production, but it is not known how mulches affect Japanese beetle grubs or the effectiveness of beneficial nematodes to control grubs. We placed grubs in soil beneath different mulches in the laboratory and tested two nematodes. The species H. bacteriophora killed almost all grubs in all mulches, but S. scarabaei was not as effective and was more affected by mulch type. A mulch of compost + woodchips and sawdust caused 60% grub mortality without adding nematodes. In a field experiment during October, the nematodes caused 50% grub mortality, which was lower than expected and likely due to cool soil temperatures. We recommend using H. bacteriophora for Japanese beetle grub management in blueberry, regardless of the mulch type being used. Popillia japonica Newman (Japanese beetle) is an invasive, polyphagous pest in North America, as adults feed on plant foliage and larvae on roots. Management in crops relies on foliar and soil applications of insecticides, but entomopathogenic nematodes (EPN) are effective biocontrol agents. In highbush blueberry, mulches (composts, woodshavings, sawdust, bark) are used for weed control and fertility. Therefore, our objective was to determine the effects of Heterorhabditis bacteriophora and Steinernema scarabaei on third-instar P. japonica in substrates commonly used as mulches in blueberry. In containers in the laboratory, larval mortality was 90–100% with H. bacteriophora for all substrates, but rates with S. scarabaei were lower and variable among substrates. A mixture of municipal compost + woodchips/sawdust resulted in 60% larval mortality without adding EPN, but few nematodes were recovered, indicating other causes of death. In a field microplot experiment in October, larval mortality rates were 50% at most for all EPN and substrate type combinations, likely due to lower than optimal soil and substrate temperatures for EPN survival and infectivity. Overall, a compost and woodchip/sawdust mulch should help suppress P. japonica populations in blueberry, and applying H. bacteriophora when temperatures are optimal to mulches can provide excellent larval control. [ABSTRACT FROM AUTHOR]

Blueberry (Vaccinium spp.) plants are exposed to existing and emerging viruses as a result of expanding acreage of blueberry plantations across the world, primarily in North America. Since blueberry is cultivated in areas where there are wild Vaccinium spp., there is increasing risk of virus movement between wild and cultivated blueberries. This is theoretically possible because viruses can spread from commercial cultivars to native species and vice versa causing the spread of existing and new viruses. The occurrence of these viruses in blueberry can be devastating to the industry considering the cost for cultivation and production of this perennial crop. However, the advent of high-throughput sequencing and bioinformatic sequence analysis have allowed for rapid identification of known and novel viruses in any crop including blueberry, thus facilitating proper intervention in response to serious viral diseases. In this paper, we aim to focus on the current status of known and novel viruses emerging in blueberry worldwide, which may impact the blueberry industry. [ABSTRACT FROM AUTHOR]

Wild blueberry is a native plant managed as a crop in northeastern North America. Fruit drop in wild blueberry, Vaccinium angustifolium Aiton, was studied over 6 years (1996–1999, 2008 and 2011). Three hypotheses were tested regarding fruit drop mechanisms from plants (clones) sampled in the field: (1) proportional fruit drop; (2) constant or uniform fruit drop; and (3) pollen or resource limitation. In addition, the temporal rate of fruit drop was measured between the end of pollination (petal fall) and fruit maturity just prior to harvest (2008 and 2011). The dynamics of fruit drop were different in the two years. The role of pollination intensity in fruit drop was also assessed. Evidence for both proportional fruit drop and resource limitation at the clone level was found but only proportional drop at the field level. Low levels of seed set are associated with fruit drop. In a four-year study (1996–1999), fruit drop ranged from 23.3 to 49.4% of the total set fruit. Partitioning the variance in fruit drop between years, fields and clones (plant genotypes) showed that the highest variation is between stems within clones (37.4%) and clones (plant genotype) within fields (35.4%), followed by between fields (19.8%) and between years (7.4%). [ABSTRACT FROM AUTHOR]

The article presents information about publication and marketing of small fruits. The issue of the journal is covering articles on various aspects of small fruits. The journal is also compiling papers presented at a conference of blueberry researchers. The popularity of berries among consumers in North America is growing. It is said that blueberry sales have risen because of a research detailing their benefits.

Hypertension is a major risk factor for cardiovascular disease, the number one cause of disability and death in North America. Thus, strategies (e.g. diet modification, drugs) to manage hypertension are essential. Lowbush blueberries (Vaccinium angustifolium) are rich in polyphenolic antioxidants which are beneficial to stroke, and may have vasorelaxation effects. We fed spontaneously hypertensive stroke-prone rats (SHrSP) and control rats (CON) either control diet or a diet containing 3% freeze-dried blueberry extract for 8 wks, to determine effects of blueberry diets on systolic blood pressure (BP). BP increased in both SHrSP groups over 8 wks. However BP in SHrSP on control diets was significantly higher than in CON by wk 4 (p=0.016), while BP in SHrSP consuming blueberries was not significantly elevated relative to CON until wk 7 (p=0.001). Maximum BP was 216 ± 11 mmHg (wk 7), and 178 ± 15 mmHg (wk 8) in SHrSP consuming control and blueberry diets respectively. At wk 6, BP of SHrSP on blueberry diet was 30% lower (p=0.002) than in SHrSP on control diet. In a separate group of SHrSP fed blueberries for 6 wks, a 48% lower glucose/insulin ratio was seen compared to rats on control diet (P=0.08, n=3). These results indicate that a 3% blueberry diet is capable of delaying the onset and reducing the magnitude of hypertension, and may reduce insulin resistance in SHrSP. [ABSTRACT FROM AUTHOR]