Search Results

You are looking at 21 - 30 of 32 items for

  • Author or Editor: Carolyn DeMoranville x
  • Refine by Access: All x
Clear All Modify Search
Free access

Justine E. Vanden Heuvel and Carolyn J. DeMoranville

Competition between fruit and upright growth in cranberry has not been previously studied, but negative correlations reported between upright length/dry weight and yield indicate that sink demand from vegetative tissues may reduce fruit production. `Stevens', `Howes', and `Early Black' uprights and fruit were collected on either a weekly or bi-weekly basis through the growing seasons of 2002–04. The data indicated a shifting of resource allocation from leaf area and dry weight accumulation to fruit growth when about 1500 growing degree days (GDD, base 4.5 °C) had accumulated. Following the initial surge in fruit growth, leaf area and dry weight accumulation resumed at roughly 2300 GDD, resulting in a competition for resources with the developing fruit until after 3000 GDD. A lag phase in fruit diameter and dry weight accumulation was noted in some cultivars in some years, and may be partially due to the resumption of leaf growth. Roots, uprights, and fruit may all compete for resources during the hottest portion of the growing season.

Free access

Hilary A. Sandler and Carolyn J. DeMoranville

Field conditions associated with commercial cranberry (Vaccinium macrocarpon Ait.) production were simulated in greenhouse studies to determine the effect of soil surface characteristics on dichlobenil activity. Sand was compared with organic matter, in the form of leaf litter, as the surface layer. A seedling bioassay using alfalfa (Medicago sativa L.), a dichlobenil-sensitive plant, was employed to determine root growth response on herbicide-treated soil. When the herbicide was applied to a sand surface, root growth was greater as time after application elapsed, indicating loss of herbicide activity. Conversely, the presence of organic matter on the surface prolonged the activity of the herbicide. Composition of the surface layer was more important than the depth of the layer in determining herbicide persistence. The influence of cultural practices, such as the application of sand or the removal of surface debris, on herbicide activity should be considered when planning weed management strategies for cranberry production. Chemical name used: 2,6-dichlorobenzonitrile (dichlobenil).

Full access

Hilary A. Sandler, Carolyn J. DeMoranville, and Wesley R. Autio

A 2-year field trial examined the interaction of nitrogen rate, vine density, and weed management options for establishing new cranberry (Vaccinium macrocarpon) plantings. Utilizing the vigorous hybrid, `Stevens', the cost-efficiency of the treatment combinations was evaluated by combining cranberry and weed biomass data with various economic estimates. The most cost-effective production scheme for establishing new cranberry beds is to plant vines at a low density, use moderate rates of nitrogen, and apply an annual application of a preemergence herbicide. This combination produced substantial vine coverage at very low cost, reduced weed biomass by 85% compared to untreated plots, and gave the best weed control per dollar spent. Growers may opt for other reasonably successful combinations that involve higher labor costs if they can produce their own cuttings (reducing initial costs) or if they are farming with the intent to reduce overall synthetic inputs.

Free access

Carolyn DeMoranville, Brian Howes, David White, and Daniel Shumaker

Although cranberry production typically requires a low fertilization rate compared to many crops, bog waters are generally discharged through surface water flow directly to streams, ponds or lakes and indirectly to coastal waters. Since discharge is primarily to fresh water bodies, and since such waters are generally phosphorus-limited, P is the fertilizer element of most environmental concern in Massachusetts cranberry production. This study was designed to determine how much P enters and leaves cranberry bog systems on an annual basis, what activities contribute to nutrient releases, and what management changes can reduce P discharges. On a total budget basis, including fertilizer applications as inputs and crop and other biomass (leaves) removal as outputs, the bogs were generally net importers of total N and total P. However, total P in outgoing waters was greater than that in source water. Net TP fluvial output averaged 2.08 kg·ha–1·yr–1 in 2002 (range 0.01 to 4.15); 1.66 kg·ha–1·yr–1 in 2003 (range –0.63 to 3.62) and 1.22 kg·ha–1·yr–1 in 2004 (range –1.24 to 4.30). The primary path of nutrient discharge from the bogs was through surface water. Flooding events were the primary source of total P output from the cranberry bogs. Gross total P export from the cranberry bogs was within the range of that for other reported agricultural land uses but greater than that for forested lands. When fertilizer P input was reduced (20% to 35%) at cranberry bog sites for two consecutive seasons, crop yield was not adversely affected and P discharge was reduced compared to that in the initial (prereduction) year.

Free access

Zi Wei, Peter Jeranyama, Fan Zhang, Carolyn DeMoranville, and Harvey J.M. Hou

Yellow vine symptoms are often observed in cranberry bogs. To explore the mechanisms of the formation of yellow vine syndrome in cranberry leaves, the shade effect on the chlorophyll (Chl) content and photosynthetic activities in cranberry bogs were investigated by spectrometric, high-performance liquid chromatography (HPLC), and in vivo Chl fluorescence kinetics. Spectrometric and HPLC analyses revealed that the yellow vine leaves were associated with a 11% ± 5% and 14% ± 5% increase in Chl a/Chl b ratio after shading, respectively. The Chl a/Chl b ratio was the same in both types of leaves, suggesting the photosystem (PS) II organization remains invariant. The rise in chlorophyll content suggested that the number of reaction sites on PS II is increased in the shaded yellow vine leaves. The results of in vivo chlorophyll fluorescence analysis also indicated that the electron transport chain in the PS II is enhanced and that the size of the quinone pool is increased. In addition, the overall photosynthesis index is drastically improved by shading. These three lines of evidence imply that the shading of cranberry plants appeared to reduce the syndrome by improving the photosynthetic activity and increasing the chlorophyll content. The techniques presented here may be valuable for characterizing variations of plants by stress or disease.

Full access

Laura K. Hunsberger, Wesley R. Autio, Carolyn J. DeMoranville, and Hilary A. Sandler

Over a 2-year period, 11 cranberry (Vaccinium macrocarpon) farms in southeastern Massachusetts were selected to evaluate mechanical removal of swamp dodder (Cuscuta gronovii) with a conventional hand-held bamboo rake. This technique consisted of breaking and removing large strands of the parasite that connected host plants; embedded and encircled portions of the parasite were not removed. Differences in dodder biomass, cranberry yield, and berry weight were determined in plots that received zero, one, or two weed-removal events. Removing dodder one time per season reduced percentage of weed cover by more than 74% in both years. Impacts on dodder fresh and dry weight were not as discernible. Removal initially decreased dodder biomass, which remained 20% to 40% lower than the baseline values, but removal treatments did not differ statistically from the control. No additional benefits were obtained by removing the weed cover more than once. Biomass per berry was not affected by mechanical weed removal and fruit of marketable size were produced in the treated area. Substantial yield loss was largely attributable to the dodder infestations, but multiple removals may eventually reduce yield to levels below those associated with infestations alone.

Free access

Bernadine C. Strik, Teryl R. Roper, Carolyn J. DeMoranville, Joan R. Davenport, and Arthur P. Poole

This research was undertaken to document the extent of biennial bearing in flowering uprights by American cranberry (Vaccinium macrocarpon Ait) cultivar and growing region. Seven cultivars were studied: three found in all states considered (Massachusetts, New Jersey, Wisconsin, Oregon), two common to Massachusetts and New Jersey, and two other commercially grown cultivars, one each from Wisconsin and Oregon. There were significant cultivar, region, and cultivar × region interaction effects for both percent return bloom (%RB) and percent return fruit (%RF). Percent RB ranged from 74% for `Ben Lear' in Wisconsin to 14% for `Howes' in New Jersey. `Ben Lear' differed the most in %RB among regions, from 74% in Wisconsin to 14% in Massachusetts. However, in some regions, especially in Wisconsin, many blossoms did not set viable fruit. There was no significant difference in %RB among cultivars grown in Massachusetts or Oregon; however, cultivars grown in these regions did differ in %RF.

Full access

Brett Suhayda, Carolyn J. DeMoranville, Hilary A. Sandler, Wesley R. Autio, and Justine E. Vanden Heuvel

Sanding and pruning are two practices used in the cranberry (Vaccinium macrocarpon) industry for vine management and yield stimulation. This study compared varying levels of sanding and pruning on vine canopy characteristics, yield, and economic returns for two consecutive growing seasons. Each practice was applied in Apr. 2006 at four levels. Sand was applied directly onto the vines at four depths: control (0 cm), light (1.5 cm), moderate (3.0 cm), or heavy (4.5 cm); pruning was conducted at four severities with a commercial pruner: control (not pruned), light (one pass with the pruner), moderate (two passes), and heavy (three passes). Pruning levels had no effect on upright density over the two seasons, but the heavy sanding treatment decreased the number of uprights per unit area. For the first season only, light penetration to soil level increased linearly as severity increased for pruning and sanding. The number of reproductive uprights relative to total uprights decreased in the first year as severity increased for both practices. This effect continued in the second year for sanding treatments. Cumulative yield and net returns were higher in light severity treatments compared to those in the moderate and heavy treatments. Moderate and heavy sanding treatments were associated with lower yields and net returns than those for the untreated controls.

Free access

Fan Zhang, Zi Wei, Peter Jeranyama, Carolyn DeMoranville, and Harvey J.M. Hou

Numerous observations of yellow vine syndrome of cranberry have been reported from commercial cranberry growers. The molecular mechanism resulting in yellow vine syndrome is unknown. We have previously reported on the shading effect as an approach to explore the mechanisms of yellow vine formation and proposed photoinhibition as a possible cause. To compare the photosynthetic performance of yellow vine-affected and normal cranberry leaves, we conducted chlorophyll fluorescence analyses over 1 period of 1 day and 3 weeks, respectively. Both experimental data sets indicated that the maximum quantum efficiency of photosystem II, the size of the quinone pool, the numbers of reaction centers (RCs) per chlorophyll absorption, and the photosynthesis performance index of the yellow vine samples are substantially lower than those of normal cranberry leaves. These results are in line with the data of yellow vine leaves, having 26% to 28% less in chlorophyll than the normal leaves as measured by spectrometric and high-performance liquid chromatography analysis. We concluded that yellow vine syndrome is associated with poor photosynthetic activity and is likely becoming a threat for the long-term growth and crop production of cranberries.

Full access

Laura K. Hunsberger, Carolyn J. DeMoranville, Hilary A. Sandler, and Wesley R. Autio

Uniformity of sand deposition on cranberry (Vaccinium macrocarpon) farms was examined to evaluate the potential use of two sanding methods to suppress swamp dodder (Cuscuta gronovii) seedling emergence by seed burial. During a 2-year study, 24 farms were evaluated with sand applied by either water barge or directly on ice. To measure the depth of sand deposited on the surface, soil cores were taken every 5 m in a grid pattern on a randomly selected portion of a commercial Massachusetts cranberry farm. Both application methods delivered nonuniform depositions of sand with the majority of the samples measuring less than the target depth. Surface diagrams depicting sand depths indicated no particular patterns of error or deposition that could be advantageously adjusted by the grower at the time of application. Mean actual: target depth ratios were 63% and 66% for barge and ice sanding, respectively (100% indicating actual equaled target). In the best scenario (two farms), 47% of the sanded area received less than the target amount; 11 farms had at least 90% of actual sand depths below the target depth. For farmers targeting 25-mm sand depths (depth expected to suppress dodder germination), the mean actual: target depth ratio was 58%, indicating half of the actual sand depths measured less than 15 mm. Compaction of the sand layer due to the elapsed time period (6 weeks or more) between sand application and measurement may have contributed to the large number of samples that were lower than the target depth. Even so, the irregularity of deposition patterns and the large proportion of sand depths that were less than 25 mm indicated adequate suppression of dodder seedling emergence would be unlikely with either sanding method.