Cranberry Beds Research Articles

The Barren Berry phenotype: untangling cranberry (Vaccinium macrocarpon Ait.) genetic contamination in central Wisconsin and beyond

Wisconsin is the world’s leading producer of cranberries (Vaccinium macrocarpon Ait.; 2n = 2x = 24). The state produces over twenty-thousand acres that contribute to more than 50% of the global total production, with more than one billion dollars in value. Cranberry growers in the “central sands” of Wisconsin have been experiencing yield decline due to vegetative unproductive genotypes, popularly known as “Barren Berry’’, which consistently remain vegetative and produce no fruit. The purpose of this study was to compare visual inspection in the field to DNA fingerprinting for the early detection of unproductive/barren genotypes. Additionally, the study served as a survey of unproductive genotypes in central Wisconsin, the largest growing region in the world. A total of 839 cranberry leaf samples, from 14 growers representing plantings to four cultivated varieties, were submitted for DNA testing of two visually determined phenotypes: unproductive or barren (n = 646; those that produced little to no fruit), versus productive or fruiting (n = 193). We conducted genetic fingerprinting on the leaf tissue using nine microsatellite markers previously shown to differentiate cranberry genotypes. This study identified a barren berry genotype unique to central Wisconsin, which we denoted “Barren Berry 1”. This genotype accounted for 43% of samples submitted as the barren berry phenotype. Genetic fingerprinting revealed sixty-five different genotypes in beds which were thought to be monocultures of just four cultivated genotypes. Early detection of genetic contamination through visual inspection, genetic testing, and responsible propagation can drastically aid in the management and longevity of cranberry beds, and in turn save time and money to the growers.

Impacts of genotype, edaphic factors, and plant nutrients on yield and fruit quality for a perennial specialty crop (Vaccinium macrocarpon Ait.)

AbstractCompared to conventional crops, less is known about how genetic and environmental variability affect the yield and quality of specialty crops like cranberry (Vaccinium macrocarpon Ait.). Herein, we performed a multifaceted analysis of six commercial cranberry beds planted to the Stevens cultivar. The six beds included three with above‐average multiyear yields and three that were lower than average. We considered genotype, edaphic factors, and plant nutrient content as driving variables of yield and fruit quality. We found that genetic purity within beds raised the odds of obtaining above‐average yields over an 8‐year period. The highest levels of genetic contamination (38%–75%) were found at the low‐yield beds, where significant differences in yield and fruit quality were observed between genotypes, within beds. Across all beds, focusing only on plots genetically confirmed to be Stevens cultivar, we also found that plot‐scale yield in 2020 was significantly higher for two of three high‐yield beds, suggesting other factors besides genetic contamination influenced differences in bed‐scale yield. A factor analysis of mixed data that jointly included genotype, edaphic variables, and plant tissue nutrient content revealed complex relations among these variables that were tied to grouping plots based on long‐term yield. Findings highlight the need for further research into the complex genetic and environmental factors that control cranberry yield and fruit quality.

First Report of Neofabraea actinidiae causing a Cranberry Fruit Rot in Oregon.

Cranberry (Vaccinium macrocarpon, L.) is a commercial small fruit that is native to North America. Oregon ranks fourth in cranberry production in the U.S.A. with 1052 Ha of cranberry beds and annual production of 23,590 metric tonnes (USDA NASS 2021). Cranberry fruit rot diseases are caused by a complex of 15 fungal pathogens belonging to 10 genera (Polashock et al. 2017). In fruit rot surveys of 'Stevens' cranberry beds in Coos and Curry Counties, Oregon, berries were collected before harvest and sorted by symptoms (e.g. softening, shriveling, or discoloration). Cranberries with field rot symptoms were surface-disinfested and lesion margin tissue placed on V8 agar. Cultures were incubated at room temperature and outgrowing fungi were transferred twice onto fresh V8 agar to obtain single isolates. Storage rots that developed on asymptomatic cranberries held at 4°C for 8 weeks were processed similarly. Since 2017, we periodically isolated Neofabraea actinidiae, which is not a member of the cranberry fruit rot complex, from rotted cranberries (Polashock et al. 2017). In 2022, N. actinidiae was isolated from 22% of 45 cranberries collected from an organically managed farm and developed storage rot and from 6% of 50 storage-rot cranberries from three conventionally managed farms. Symptoms associated with N. actinidiae on 'Stevens' cranberries often include softening and brown tissue surrounded by a yellow-colored ring. On V8 agar, N. actinidiae grew as compact white circular colonies with dense aerial hyphae near the center and accompanied by a red pigment in the agar. Pink-colored mucoidal irregular conidiomata often developed on the colony after 3 weeks. Conidia were hyaline, aseptate, and ellipsoidal to fusiform ranging from 7.5 to 12.6 µm long X 3.5 to 5.6 µm wide (n=100). Genomic DNA was extracted from N. actinidiae isolates from cranberries in 2017 and 2022. β-tubulin and the ITS 5/4 region were amplified and sequenced with primers Bt-T2m-Up/Bt-LEV-Lo1 and ITS5/ITS4 using conditions of de Jong et al. (2001) and White et al. (1990), respectively. Sequences were deposited in NCBI Genbank (Accessions: OR606303, OR606305, OR606306, & OR606309 for ITS; OR610314, OR610316, OR610317, & OR610320 for β-tubulin). BlastN analysis of β-tubulin (695 bp) and ITS (489-490 bp) had a 99.6 to 99.8% and 99.8 to 100% identity, respectively, to Neofabraea actinidiae (CBS 121403) (Accession numbers: KR859285 β-tubulin and KR859079 ITS). Phylogenetic analysis of concatenated sequences using Tamura-Nei neighbor-joining (Tamura et al. 2004) confirmed identity of cranberry isolates as N. actinidiae. Koch's Postulates were confirmed with four N. actinidiae isolates from cranberry. Agar or hyphal plugs were placed in a 3 mm wound on the side of six surface-disinfested, asymptomatic berries and incubated in a moist chamber at 20°C for 15 days or 4°C for 55 days. Similar symptoms developed on each berry inoculated with N. actinidiae, but not agar alone. The fungus was recovered from symptomatic tissues and identity confirmed by colony morphology. N. actinidiae causes a ripe rot and storage rot in kiwifruit and is one of the species causing Bull's Eye Rot of pome fruits (Tyson et al. 2019). Cryptosporiopsis actinidiae (anamorph) was isolated from cranberries roots in British Columbia, CA, but considered unlikely to be the causal agent of dieback disease of cranberry vines (Sabaratnam et al. 2009). We have demonstrated that N. actinidiae causes a cranberry fruit rot in beds and in storage. Its prevalence, associated fruit rot symptoms, and disease incidence will continue to be monitored.

Integrating sequential applications of residual and postemergence herbicides for controlling Carolina redroot (Lachnanthes caroliniana) in cranberry beds

Abstract Carolina redroot (LAHTI) is a perennial weed of New Jersey cranberry beds. It is associated with “stand opening” areas that result from fairy ring dieback or other conditions of natural and anthropogenic origin. LAHTI accounts for significant yield reduction through direct competition with cranberry for nutritional resources. Field experiments were conducted from 2017 to 2022 on ‘Ben Lear’ and ‘Early Black’ cranberry beds in Chatsworth, NJ, to determine 1) the efficacy of residual herbicides labeled for use on cranberry, and subsequently, 2) to evaluate the value of overlapping preemergence applications of napropamide and postemergence applications of mesotrione for LAHTI control while minimizing crop phytotoxicity. Treatments in the first experiment included preemergence applications of dichlobenil or norflurazon at 2.2 and 4.5 kg ha−1 and napropamide a 6.7 kg ha−1. In the second trial, napropamide was applied preemergence annually to plots at 6.7 or 10.1 kg ha−1 either as a single or as two equally or unequally split applications spaced 30 d apart, followed by or not followed by mesotrione applied postemergence at 280 g ha−1 when LAHTI leaves emerged above the cranberry canopy. The preemergence herbicides dichlobenil applied at 4.5 kg ha−1 and napropamide provided ≥48% LAHTI control and ≥40% LAHTI biomass reduction 112 d after treatment (DAT), whereas norflurazon had no significant effect on LAHTI biomass. Less than 4% of crop injury and liquid formulation adapted to chemigation identified napropamide as an effective preemergence herbicide for LAHTI control. In the second trial, napropamide applied at 10.1 kg ha−1 followed by an application of mesotrione reduced LAHTI biomass by ≥73%. Splitting napropamide application reduced yield by 36% and berry weight by 12% compared with a single application at the dormant stage. Compared with the nontreated control, a single napropamide application at 10.1 kg ha−1 followed by an application of mesotrione increased yield by 38%. Information derived from these studies is already being used by growers to enhance the productivity and profitability of New Jersey cranberry fields.

The New Cranberry Wisconsin Research Station: Renovation Priorities of a ‘Stevens’ Cranberry Marsh Based on Visual Mapping, Genetic Testing, and Yield Data

ABSTRACT Cultivar contamination is a common issue in commercial cranberry production. Unknown or unwanted cranberry genotypes are found in commercial cranberry beds that are intended to be a single uniform genotype. Identification of contamination and the impact of contamination remain crucial issues for the cranberry industry to maintain long-term high productivity. To address this issue, tissue samples were taken from the former commercial beds of the new Wisconsin Cranberry Research Station (WCRS) for genetic fingerprinting analysis. The goal of this collection was to analyze the 10 beds for genetic uniformity to determine if any should be maintained or replaced, and to assess the accuracy of visual perception of genetic contamination in the field. A total of 288 DNA samples were collected in the 10 cranberry beds, and the ‘Stevens’ cultivar represented 180 samples or 69% of the 261 samples expected to be ‘Stevens.’ Therefore, the genotype contamination in the ‘Stevens’ beds was 31% overall. Overall, visual differentiation was accurate in distinguishing between genotypes and detecting large areas of contamination. A yield analysis was conducted along with the genotypic uniformity assessments, and a significant correlation was found between the 2017 yield of the beds and their level of genetic contamination. This study demonstrates the usefulness of genetic uniformity testing and mapping for cranberry bed management and renovation decision-making.

Cranberry Germination and Emergence Response to Environmental Factors and Seeding Depth

Cranberry (Vaccinium macrocarpon Ait.) cultivars are clonally propagated. Germination of cranberry seeds produces off-type varieties that are generally characterized by lower fruit productivity and higher vegetative vigor. Over time, the productivity of cranberry beds decreases as off-type frequency increases over time. Improved knowledge of cranberry germination biology would facilitate the use of targeted agronomic practices to reduce the emergence and growth of less productive off-types. The influences of light, temperature regime, pH, and water potential on cranberry seed germination were assessed in a growth chamber, whereas the effect of seeding depth on seedling emergence was evaluated in a greenhouse. Seeds stratified for 6 months at 3 °C were used for these experiments. Cranberry germination was influenced by light quality, with maximum germination reaching 95% after 15 minutes of exposure to red light but decreasing to 89% under far-red light. However, light was not required for inducing germination. Cranberry seeds germinated over a range of alternating diurnal/nocturnal temperatures between 5 and 30 °C, with an average maximum germination of 97% occurring for diurnal temperatures of 20 to 25 °C. The length of emerged seedlings was reduced by an average of 75% for pH 6 to 8 compared with pH 3 to 5. Seedlings that emerged at pH greater than 5 showed increasing chlorotic and necrotic injuries and were not considered viable at pH 7 or 8. Germination at 15 °C was reduced when seeds were subjected to water stress as low as −0.2 MPa, and no germination occurred below −0.4 MPa. Seeds incubated at 25 °C were more tolerant to water stress, with at least 70% maximum germination for osmotic potential (ψS) −0.6 MPa or greater. The average seedling emergence was 91% for seeds left on the soil surface or buried at a maximum depth of 1 cm; however, it was null at a burying depth of 4 cm. These results indicate that germination of cranberry seeds in cultivated beds in the northeastern United States likely occurs during the summer months, when temperatures are optimal and the moisture requirement is supported by irrigation. However, timely application of residual herbicide or sanding (a traditional cranberry agronomic practice) of open areas in cranberry beds could help prevent seed germination and reduce minimizing the onset of off-type varieties.

Status and ecology of the boreal moss Dicranum undulatum Schrad. ex Brid. at its last location in southern Britain

ABSTRACT Introduction. Dicranum undulatum has been lost from many sites due to destruction of peatlands. This study investigates its status and ecology at the last surviving location in southern Britain. Methods. The study site, Fenn’s, Whixall, Bettisfield, Wem and Cadney Mosses, is one of the largest lowland raised bogs in Britain. Distribution and abundance of Dicranum undulatum was documented with GPS-based survey and habitat and community composition via relevés. Elevation of D. undulatum and Rest Water Level (RWL) relative to the peatland surface was measured at a sample of colonies and a search for sporophytes undertaken at all colonies. Results. Dicranum undulatum was found in two areas, the vast majority at Cranberry Beds plus a small amount at Welsh Bettisfield Moss. Its community is dominated by mosses and vascular plants, most frequently Aulacomnium palustre, Erica tetralix, Eriophorum vaginatum and Vaccinium oxycoccos. Soil pH is highly acidic, similar to the upper water table. Electrical conductivity of the upper water table is low. Elevation of RWL relative to soil surface averaged −10.8 cm. Minimum and maximum elevation of shoot tips of D. undulatum relative to soil surface averaged 7.4 and 24.8 cm, respectively. Maximum height of the moss above RWL averaged 35.6 cm. No sporophytes were found. Conclusions. Strictly limited to uncut peatland, the study site supports a strong population of Dicranum undulatum. It survives at Welsh Bettisfield Moss despite it being covered by dense woodland until tree clearance in 2001. Reproduction appears limited to clonal spread via detached shoot tips.

Sources, Transport, and Management of Phosphorus Loss during the Cranberry Harvest

Wet (flood) harvesting is essential to commercial cranberry (Vaccinium macrocarpon Ait.) production in Massachusetts, where one‐fifth of the US cranberry crop is produced. However, periodic flooding may lead to impaired water quality in lakes that receive harvest flood discharges. In this study, harvest flood inputs and outputs of P were measured to determine the net flux of P (Mnet) from a 19.2‐ha cranberry bog and its five bog units. Results showed that the cranberry bog was a source of dissolved P (DP) (Mnet = 0.32 kg P ha−1) and a minor sink of particulate P (PP) (Mnet = −0.03 kg P ha−1). For the five bog units, values of Mnet were highly variable, ranging from −0.49 to 1.48 kg P ha−1 with a coefficient of variation of 223% for DP. Variation in Mnet was not strongly related to P fertilizer rate, soil test P, or flood holding time, but was inversely related to the water flux from the cranberry bog to the underlying aquifer. Groundwater concentrations of DP were not statistically different before, during, or after the harvest flood, suggesting minimal subsurface leaching of P to shallow groundwater. Collectively, these findings point to soil P retention in some cranberry bogs, as might be expected in natural wetlands. Although there is potential for subsurface P leaching, the use of select cranberry bogs as filter beds of high‐P floodwater may help to curtail surface water export of P from cranberry agriculture.Core Ideas Wet (flood) harvested cranberry bogs may contribute to water quality problems. Harvest flood P losses varied from 0.49 to 1.48 kg P ha−1 for five cranberry beds. Harvest flood P losses were not related to P fertilizer, soil P, or flood length. Rather, the best indicator of harvest flood P loss was groundwater recharge. Groundwater recharge may facilitate P sorption and reduce harvest flood P losses.

A Molecular Assay Allows the Simultaneous Detection of 12 Fungi Causing Fruit Rot in Cranberry.

Cranberry fruit rot (CFR) is arguably one of the most limiting factors of cranberry (Vaccinium macrocarpon) production throughout its growing areas. The disease is caused by a group of closely related fungi that require identification using long and cumbersome steps of isolation and microscopic observations of structural features. The objective of this study was to develop a molecular assay to simultaneously detect and discriminate 12 of the most important fungal species reported to be pathogenic on cranberry fruit to facilitate the diagnosis of CFR. As the first approach, internal transcribed spacers and large subunit regions of all fungi were sequenced and confirmed with sequences available in the NCBI database. These data were used to develop primers able to differentiate seven of the 12 species. The five remaining species, including three in the Phacidiaceae family and two in the Glomerellaceae family, were differentiated on the basis of a more discriminant marker, the translation elongation factor 1-α. Two PCR reactions were optimized to clearly delineate the 12 species. The multiplex test was first validated using pure fungal cultures; it was subsequently validated using fruit collected in cranberry beds in eastern Canada. In the latter case, the test was rigorous enough to clearly discriminate the fungal pathogens from contaminants. Within the tested samples, Physalospora vaccinii and Coleophoma empetri were most commonly found. This molecular test offers scientists, diagnosticians, and growers a powerful tool that can rapidly and precisely identify fungi causing CFR so they can implement appropriate control methods.

Carolina redroot (Lachnanthes caroliniana) vegetative growth and rhizome production as affected by environmental factors and planting depth

AbstractCarolina redroot [Lachnanthes caroliniana (Lam.) Dandy] is a frequent weed of New Jersey cranberry (Vaccinium macrocarpon Aiton) bogs that competes with the crop for nutritional resources. Studies were conducted in 2018 to determine the effects of planting depth, soil moisture, lighting conditions, rhizome water content, and duration of rhizome submersion under water on L. caroliniana shoot emergence, vegetative growth, and rhizome development. Only planting depth greater than 12 cm significantly reduced shoot emergence (54%), biomass shoot and root production (27% and 65%, respectively), and rhizome formation (65%) compared with a 2-cm depth. Complete inhibition of new rhizome production was observed when the rhizome water content dropped to 30%. Soil moisture ≤30% decreased shoot biomass by ≥53% compared to 60% soil moisture, but marginally affected root biomass and had no impact on rhizome formation. Rhizome submersion for at least 120 d had minor effect on shoot emergence but reduced plant biomass by ≥28% and completely inhibited the formation of rhizomes. Finally, shading did not influence emergence but had a more dramatic effect on root and shoot biomass, which were reduced by 53% and 75%, respectively, and prevented the development of new rhizomes. This study demonstrates the plasticity of L. caroliniana to drought stress or long-lasting flooding conditions, therefore preventing consideration of cranberry bed temporary flooding or limitation of irrigation volume and frequency as viable management options. Sanding would not provide a layer of material sufficiently thick for reducing L. caroliniana shoot emergence. Reducing the quantity of light reaching the soil with black tarps or promoting rapid crop canopy closure are options that can complement the use of mesotrione for controlling L. caroliniana. Future research should address the practicality of these options, especially in bogs with low L. caroliniana pressure when early-summer weed regrowth occurs following dissipation of PRE herbicide activity.

Carolina Redroot (Lachnanthes caroliniana) in Cranberry: Assessment of Shoot and Rhizome Control with POST Herbicides

AbstractCarolina redroot is a common weed of New Jersey cranberry beds that competes with crops for nutritional resources but also serves as a food source for waterfowl. Greenhouse studies were conducted in 2017 in Chatsworth, NJ, to determine control of Carolina redroot aboveground vegetation and rhizome production with 10 herbicide active ingredients. Herbicides were applied as a single application on 10- to 15-cm-tall plants. Diquat at 560 g ai ha−1and mesotrione at 280 or 560 g ai ha−1controlled more than 90% of emerged shoots at 63 d after treatment (DAT). Aboveground vegetation control at 63 DAT reached 87% with 2,4-D and flumioxazin but was limited with glyphosate, not exceeding 40%. Mesotrione at 560 g ai ha−1provided 98% control of roots and rhizomes (root/rhizome) at 63 DAT, a 10% increase compared with 280 g ai ha−1; and 2,4-D (90%), glyphosate (87%), diquat (86%), and flumioxazin (85%) also showed excellent root/rhizome control. The greatest reduction of plant biomass compared with the nontreated check (UNT) was noted with 2,4-D, mesotrione at 280 g ai ha−1and 560 g ai ha−1, and diquat, with decreases from 73% to 80% for shoots and from 82% to 88% for roots/rhizomes. Glyphosate had less impact on shoot biomass reduction (−56%) but similar effect on root/rhizome dry weight (−79%) compared with 2,4-D, mesotrione, and diquat. Flumioxazin and fomesafen significantly reduced root/rhizome biomass by 78% and 72%, respectively. Concurrently, 2,4-D, flumioxazin, fomesafen, and diquat reduced the number of secondary shoots 70% to 90% compared with the UNT, whereas glyphosate and mesotrione completely inhibited emergence of new shoots. These data suggest that mesotrione applied POST provides excellent control of Carolina redroot. Future research should evaluate field applications of mesotrione in early summer when Carolina redroot regrowth occurs following the dissipation of PRE herbicide activity.

Bees (Hymenoptera: Apoidea) Foraging on American Cranberry in Massachusetts

Abstract We studied diversity and abundance of bees foraging on Vaccinium macrocarpon (American Cranberry) flowers in southeastern Massachusetts during 8 bloom periods between 2007 and 2016. We documented 6 families, 20 genera, and 72 species of bees. Only Bombus (bumble bee) species were abundant in any of the collection years. Ways in which the upland areas surrounding cultivated cranberry beds and American Cranberry itself may be inhospitable for many small-bodied bee populations with limited flight ranges are reviewed. Bombus dominated (>90%) the collection. Comparison with observations in the first half of the 20th century, together with collections made during a less-intensive survey 25 years ago, suggest that 2 Bombus species are increasing in abundance, but that at least half of the Bombus species previously observed in this region have become rare or locally extinct.

Seasonal dynamics of water and nutrient fluxes in an agricultural peatland

AbstractThe American cranberry (Vaccinium macrocarpon Ait.) is an important part of the cultural heritage and economy of Southeastern Massachusetts, yet water quality concerns and wetland protection laws challenge its commercial production. Here, we report inputs and outputs of water, nitrogen (N), and phosphorus (P) for a 2.12‐ha cranberry bed over a 2‐year period from 2013 to 2015. Water‐budget analysis indicated that precipitation contributed 40%, floodwater 37%, irrigation 15%, and groundwater 8% of water inputs to the cranberry bed. Minor annual variation in surface water discharge (~90 mm·year−1 or 3%) contrasted with large decreases in net (= outputs − inputs) nutrient export, from 16.2 to 9.1 kg N·ha−1·year−1 for total (dissolved + suspended particulate) nitrogen (TN) and from 3.34 to 1.47 kg P·ha−1·year−1 for total phosphorus (TP) between Years 1 and 2. Annual variation in net TN and TP export was tied to decreases in spring and summer nutrient export and controlled by the combined effects of fertilizer management, soil biogeochemistry, and hydrology. The relatively high spring TN export in Year 1 was associated with coincident increases in soil temperature and rainfall. A second factor was the timing of fertilizer application, which occurred 1 day prior to a major summer storm (i.e., third largest daily rainfall since 1926) and was responsible for up to 15% and 9% of the Year 1 TN and TP export, respectively. Nutrient budgets, which balanced water and fertilizer inputs with water, fruit, and vegetative outputs, were consistent with the burial of 21.6 kg N·ha−1·year−1 and 7.27 kg P·ha−1·year−1. Field measurements indicated that burial would increase TN and TP in the shallow (0–5 cm) rooting zone by 14% and 6%, respectively, which seemed plausible based on the relatively young age of the bed (4–5 years) and new root growth patterns in Vaccinium plants.

Conserving carnivorous arthropods: an example from early-season cranberry (Ericaceae) flooding

AbstractBiological control plays an important role in many integrated pest management programmes, but can be disrupted by other control strategies, including chemical and cultural controls. In commercial cranberry (Vaccinium macrocarpon Aiton; Ericaceae) production, a spring flood can replace an insecticide application, providing an opportunity to study the compatibility of the flood (a cultural control) with biological control. We suspect that chemical controls will tend to reduce the number of natural enemies, while the flood, through removal of detritus and detritivores, may cause generalist predators to prey-switch to consume proportionally more pest individuals. We measured the abundance of herbivores (Lepidoptera), detritivores, Arachnida, and parasitoids (Hymenoptera) every week for six weeks in Wisconsin (United States of America) cranberry beds following either an insecticide spray or a cultural control flood. We found that detritivore populations rapidly declined in both flood and spray treatments; conversely, carnivore populations (spiders and parasitoids) were more abundant in the flooded beds than in sprayed beds. Populations of key cranberry pests were similar between flooded and sprayed beds. Our results showed that early-season flooding preserved more natural enemies than an insecticide application. This increase in natural enemy abundance after the flood may allow for greater continuity in herbivore suppression, potentially providing a basis for long-term cranberry pest management.

Repeated Applications of Mesotrione and Napropamide on New Cranberry Plantings

To evaluate the weed control provided by various combinations of PRE applications of napropamide (Nap) and POST applications of mesotrione (Mes) in newly planted and 1-yr-old cranberry vines, six 2-yr experiments were conducted during 2009-2012. Three sites were treated in the year of planting plus the subsequent year (called “new plantings”) and three sites were treated in their second year of growth plus the subsequent year (called “second-year plantings”). Ten treatments, delivered in 3,735 L ha−1 water, were administered each year: Nap at 3.36 kg ai ha−1 applied once, twice, thrice or once followed by (fb) one application of Mes at 210 g ai ha−1; Nap at 5.04 kg ha−1applied once, twice or once fb one application of Mes at 210 g ha−1; Mes at 210 g ha−1 applied once or twice; and nontreated. At new planting sites, plots receiving treatments other than a single Nap application had less total weed biomass compared to nontreated plots. At second-year plantings, all herbicide-treated plots had less total weed biomass than nontreated plots; in addition, plots receiving Mes-only treatments had less total weed biomass than Nap-only treatments. Correlation analysis indicated that monocot biomass production was the primary positive predictor for total weed biomass. Herbicides did not adversely affect cranberry biomass production but overall vine colonization was poor for four of the six sites indicating that other factors, including cultivar choice, planting method, and water management, may play a larger role in rapid cranberry vine colonization than the suppression of initial weed biomass. Given the complementary range of efficacy for Nap and Mes, a combination PRE-POST herbicide program of a low rate of Nap fb Mes may be the most cost-beneficial program in many instances. If cost is a limiting factor, applying a single application of Mes to a new planting should be included as a component of cranberry bed establishment since this practice consistently resulted in significantly less initial weed biomass compared to areas left nontreated.

Cranberry SSR multiplexing panels for DNA horticultural fingerprinting and genetic studies

Cranberry (Vaccinium macrocarpon) is in need of inexpensive high-throughput DNA fingerprinting methods for genetic research and germplasm purity testing for agricultural purposes. Therefore, we designed and validated 16-multiplexing panels containing 61 evenly distributed simple sequence (SSR) markers, with non-overlapping allele ranges, throughout the 12 cranberry linkage groups. Several important cranberry cultivars and selections (n=18) and a diploid accession of V. oxycoccos were genotyped with the multiplexing panels and separated through principal component analysis (PCA) to demonstrate their effectiveness for DNA fingerprinting and genetic diversity analysis. A subset of three multiplexing panels containing 12 SSR markers was used to genotype 174 seedlings from fruits collected in a commercial cranberry bed of the cultivar Stevens, and identification of intra-cultivar heterogeneity was investigated in the bed to validate the use of the markers in such future applications. Furthermore, determining the likelihood that each seedling was self- or cross-pollinated provided the first quantitative evidence (p<0.0001) that the majority of seeds within commercial cranberry beds are self-pollinated. These multiplexing panels represent an important, applicable resource for cranberry researchers and farmers of the North American industry. These markers can be used to assess the genetic homogeneity of grower and licensed propagators’ cranberry beds, to protect the intellectual property rights of plant breeders, and to enable cranberry researchers to monitor the genetic identity of genotypes within their breeding programs and genetic studies.

Recovery of Cranberry Plants Infected With Tobacco streak virus and Incidence and Distribution of TSV in the Field.

Tobacco streak virus (TSV) has been detected in cranberry plants in Wisconsin, New Jersey, and Massachusetts, and is associated with berry scarring symptoms. In the current study, cv. Mullica Queen plants that produced scarred, symptomatic, TSV-positive fruit in one year produced nonscarred, asymptomatic, TSV-positive fruit in subsequent years, consistent with the "recovery" phenomenon previously documented in other ilarvirus-woody plant interactions. In field trials, fruit set and berry weight were significantly reduced (P < 0.05) in symptomatic, TSV-positive cranberry shoots but not in recovered, TSV-positive shoots compared with healthy, TSV-negative shoots. Likewise, return bloom in the first year following berry scarring was not negatively impacted in recovered shoots. Detection of TSV in various plant parts throughout the growing season was more variable in symptomatic shoots than in recovered shoots. Of all plant parts tested, TSV detection was lowest in berries at the time of harvest in both symptomatic and recovered shoots. Minimal increases in incidence of TSV-infected shoots in cranberry beds from one year to the next, and spatial autocorrelation of TSV-infected shoots, suggest that most new infections result from TSV spreading within a bed, rather than frequent introductions of the virus from external sources.

Water table level management as an irrigation strategy for cranberry (Vaccinium macrocarponAiton)1

Cranberry production is a water intensive practice that requires irrigation during summer months to achieve maximum yields. Previous studies have found that root zone tension maintained between −4 and −7.5 kPa allows for maximum yields without over irrigating. The present study looks at the effects of managing a water table to supplement overhead sprinkler irrigation with upward flow. Two drainage systems, controlled and free, were implemented in a cranberry bed constructed of fine sand. The controlled drainage system used existing drain tiles and a sump to maintain an artificial water table, while the free drainage system had no manipulation of the water table. Daily upward flow and water table level were measured in four locations, across the length of the bed, for each drainage system. Comparing upward flow with evapotranspiration (ET) rates, approximately 30% of maximum daily ET can be met by holding a water table between 500 and 600 mm. Numerical simulations indicate that water tables shallower than ...

Evapotranspiration from cranberry compared with the equilibrium rate1

The rate of evapotranspiration from a mature cranberry bed in Wisconsin was measured using infrared thermometry. Values ranged from 0.8 to 6.2 mm d−1, which were on average 1.05 of the equilibrium evaporation rate. These results are in good agreement with those measured earlier in Wisconsin by the Bowen-ratio technique. Estimates of stomatal conductance were extracted from the data, yielding values of at least 0.2–0.3 mol m−2 s−1, substantially higher than earlier reports for cranberry but typical of uncultivated plants. Our results give us good confidence that cranberry evapotranspiration in the continental climate of Wisconsin, at least, can be estimated from the equilibrium evaporation rate, i.e., the Priestley–Taylor potential rate, with α = 1.05.

Spatial Scale and Field Management Affect Patterns of Phosphorus Loss in Cranberry Floodwaters.

Although cranberries ( Ait.) are indigenous to the northeastern United States, phosphorus (P) fertilizer additions and periodic flooding make commercial cranberry a potential source of P to the region's lakes and streams. In this study, we report values of P export in cranberry floodwaters that range from <0.8 to 4.7 kg P ha, generally reflecting differences in the hydrological, edaphic, and management factors underlying soil P transfer to floodwater. The relatively high P loading rate (4.7 P kg P ha) was associated with harvest flooding of organic-rich soils. Periods of winter flooding and the discharge of harvest floodwater from mineral soils resulted in relatively low P loss (<0.8 kg P ha). Increases in concentrations of total dissolved P (DP) and total particulate P (PP) in floodwater as stage decreased below the surface of the cranberry bed were consistent with the transport of dissolved P in soil porewater and mobilization of particulate P in ditches. Variations in floodwater DP, as well as conservative and reactive tracer concentrations, suggested that the processes by which soil P is released to porewater included desorption of near-surface soil P and anaerobic dissolution of iron-P compounds deeper in the soil profile. At the farm scale, concentrations of DP and PP steadily increased over time, presumably because drainage waters from beds farther upgradient had longer contact times with P-rich sources, such as soil porewater and ditch sediments. Overall, the study illustrates the role that scale-dependent processes impart on patterns of P loss in agricultural production systems.