Curt Rom - Academia.edu (original) (raw)
Papers by Curt Rom
HortScience, 1994
Three studies were established to compare spring (S) vs. autumn (F) N fertilizer applications on ... more Three studies were established to compare spring (S) vs. autumn (F) N fertilizer applications on apple tree performance. The studies used newly planted trees, 4-yr-old trees, and 8-yr-old trees, fertilized with either ammonium nitrate or urea at 2 weeks after harvest (F) or at bud break (S). In the first 3 years growth in a newly planted orchard, time of fertilizer did not significantly affect tree height or TCSA. In the first cropping year, F fertilized trees had the greatest flower cluster number and bloom density but similar % set and yield compared to S fertilized trees. F fertilized trees in mature orchards studies tended to be shorter and have smaller TCSA increment after 3 yrs. Treatments did not affect bloom density, % set or total yield although spring fertilized trees had a greater % drop. Although spur leaves of F fertilized trees had greater N content at bloom, shoot leaves typically had lower N and Mn, and higher P, K, and Ca at 90 days after bloom compared to S treatme...
HortScience, 2005
Japanese beetle (Popilla japonica Newman) has caused severe damage on a wide range of horticultur... more Japanese beetle (Popilla japonica Newman) has caused severe damage on a wide range of horticultural crops since its first introduction to the Eastern United States from Japan in 1916. Leaves are skeletonized by adult beetles feeding in masses, which makes this insect damage easy to identify. In Arkansas, Japanese beetle was first trapped in Washington County in 1997 and has reached epidemic proportions in the most recent three years. Leaf skelotonization and feeding preference on eighteen birch accessions by Japanese beetle were recorded in 2003 and 2004. There was a wide range from no feeding (0% leaf skelotonization) to high feeding preference (89% leaf skelotonization). Betula utilis var. jacquemontii and B. papyrifera `Renaissance Upright' had highest preference. Betula pendula `Laciniata' had no feeding damage from Japanese beetle.
HortScience, 1991
Gas exchange (assimilation, transpiration, water use efficiency, and conductance) of `Shawnee'... more Gas exchange (assimilation, transpiration, water use efficiency, and conductance) of `Shawnee' blackberry were measured under field conditions with a portable system (ADC-IRGA with Parkinson Leaf Chamber). Gas exchange primocane pentifoliate leaflets were similar. Gas exchange rates of leaves along a cane exhibited a quadratic function of leaf position with leaves in lower-mid sections (relative position 0.3 - 0.5) having higher A, TR, WUE, gs than either basal or apical leaves. Leaves subtending fruiting laterals on fruiticanes had higher assimilation than similar age leaves on primocanes but did not differ in Tr, WUE, or gs. Primocanes had estimated dark respiration rates of 0.33mg·dm-1.hr-1, estimated light compensation at 14-20 mol.m-2.s-1, estimated light saturation at 1000-1100 mol.m-2.s-1 with maximum A rates ranging from 24-30 mg CO2.dm-1.hr-1. Measurements were made at field temperatures ranging from 24-35 C. Although temperature response was not measured, correlation i...
Soil Science, 2009
In the early 1900s, northwest Arkansas was the leading apple (Malus sylvestris Mill.)-producing r... more In the early 1900s, northwest Arkansas was the leading apple (Malus sylvestris Mill.)-producing region in the United States. To maximize yields and quality, apple producers used heavy doses of lead (Pb) arsenate at the time to control agricultural pests, particularly the codling moth (Cydia [Laspeyresia] pomonella). Northwest Arkansas is a region underlain by karst geology, specifically fractured limestone and dolomitic bedrock, which creates the potential for rapid downward transport of surface contaminants, such as arsenic (As) from past Pb arsenate usage in the region, to the groundwater. Northwest Arkansas is also presently one of the most rapidly expanding regions in the United States in terms of urbanization and population. Thus, it is critical that high-quality surface and groundwater resources are maintained as potable water sources. The objective of this study was to evaluate the effect of land use (i.e., historic apple orchard, broiler litterYamended pasture, historic orchard-followed-by-broiler-litter-amended pasture, and nonorchard/nonlittered land use) and soil depth (i.e., 0Y2, 2Y4, and 4Y8 cm) on acid-recoverable soil As, Pb, and phosphorus. Soil As concentrations were lowest in the 0-to 2-and/or 2-to 4-cm depth and increased with depth in all land uses, expect for the litter-only pastureland, in which soil As concentrations did not differ among soil depths. Soil Pb concentrations also increased with depth, but only in the orchard-followed-by-litter-amended pasture. Soil As and Pb concentrations were at least numerically greater in all soil depths in the orchardfollowed-by-litter-amended pasture than in all other land use/soil depth combinations. Soil phosphorus concentrations were greater at all depths in the land uses that received broiler litter than in those land uses that did not and decreased with depth in all land uses. The results of this study indicate that historic Pb arsenate usage seems to be more responsible for elevated soil As concentrations than even decades of annual land application of As-containing broiler litter to pasturelands that had never received Pb arsenate applications for pest control during apple production.
Acta Horticulturae, 1990
... 217. Rom, CR, and Ferree, DC, 1984. Spur leaf characteristics of nine apple cultivars. Fruit ... more ... 217. Rom, CR, and Ferree, DC, 1984. Spur leaf characteristics of nine apple cultivars. Fruit Var. J. 38:2-5. Table 3 - The influence of limb orientation on spur development of 'Delicious' apple. Spur Leaves Spurs per Specific Dry Bud Limb Area Leaf Wt. Wt. Dia. ...
Physiologia Plantarum, 1988
HortScience
The role of spur leaves in bud and fruit development on two spur-type `Delicious' apple strai... more The role of spur leaves in bud and fruit development on two spur-type `Delicious' apple strains (Malus domestica Borkh.) and factors affecting spur development were studied. Reducing spur leaf area on vegetative spurs in August reduced the number of spurs that flowered the following year but did not affect flower size. On spurs that did flower, leaf area reduction the previous year did not influence leaf number or area, but the bourse shoot leaf area was reduced. Spur bud diameter, leaf area, size, specific leaf weight (SLW), and leaf dry weight were larger on 2-year-old vegetative spurs than on 1- or 3-year-old spurs. Within each age section of a limb, spur leaf number, area, size, SLW, and bud diameter decreased from the apical to basal positions on the limb. Flower number did not vary within a limb section, but fruit set was lower on the most apical and basal spurs compared to midshoot spurs. Fruit size was largest at the apical end of each limb section and was smallest at ba...
HortScience
Light distribution in two cultivars on three dwarfing rootstocks in three high-density apple tree... more Light distribution in two cultivars on three dwarfing rootstocks in three high-density apple tree training systems was measured in the sixth leaf beginning at full bloom and continuing through the season. Training system had a significant effect on light penetration into the lowest point of the canopy (measured at 0.5 m), with the slender spindle being significantly darker than either the central leader or the vertical axis, although all three systems were below the threshold value of 30% full sun (FS) needed to maintain productivity for most of the season. Cultivar had no significant effect; however, trees of both `Jonagold' and `Empire' fell below 20% FS early in the season and remained there until late in the season. Rootstock had the greatest effect, with trees on M9 and M26 being significantly darker in the lower canopy than trees on Mark. Trees on M26 and M9 fell below 10% FS early in the season and remained there, while trees on Mark never fell below 20% FS.
HortScience
The NE-183 project was established in 1993 and the first trial planted in 1995 with the objective... more The NE-183 project was established in 1993 and the first trial planted in 1995 with the objective of evaluating new apple cultivars for horticultural, pest and disease resistance, and qualitative characteristics. Arkansas (AR) is the southernmost location for the initial planting. The following cultivars are in AR trial: `Arlet', `Braeburn', `Cameo', `Creston', `Enterprise', `Fortune', `Fuji', `Gala Supreme', `Ginger Gold', `GoldCrisp', `Golden Delicious', `Golden Supreme', `Goldrush', `Honeycrisp', `NY75414-1', `Orin', `Pristine', `Sansa', `Shizuka', `Suncrisp', `Sunrise', and `Yataka'. Bloom of `Braeburn', `Yataka', `Orin', `Gold Supreme', `Fortune', and `Enterprise' were early and may be exposed to annual spring frosts. The following cultivars ripened in July or August and may be too early for southern markets: `Pristine', `Sunrise', `Sansa', `Ginger Gold...
HortScience
Apple cultivar development is an important program necessary to sustain the existing fruit indust... more Apple cultivar development is an important program necessary to sustain the existing fruit industry and stimulate new production systems for Arkansas and the region. The cultivar development program has two parts. First, currently available cultivars are tested with multiple trees for multiple years. Second, about 150 advanced selections from the Arkansas apple breeding program are evaluated in trials with multiple trees (2nd test) and in replicated trials (3rd test). The goal of both programs is to identify cultivars that have potential in the local production systems and for Arkansas' markets, and to identify those cultivars which are not adapted to the region. All cultivars and advanced selections are evaluated for ∂35 qualitative and quantitative characteristics, including time of bloom, time of harvest, length of harvest season, fruit aesthetic and internal quality, environmental adaptability especially to heat and high light, and insect and disease susceptibility. Primary ...
HortScience
Alternate bloom thinners are needed for apple are needed to replace compounds which can no longer... more Alternate bloom thinners are needed for apple are needed to replace compounds which can no longer be used or have production system limitations. The effects of 24 chemicals selected as osmotic agents, organic acids, oils, essential oils, or potential metabolic agents and their properties of pH, electrical potential (EP) and water potential were tested in vitro on `Gala' apple pollen germination, tube growth and pistil damage. Solution concentrations of 0%, 0.25%, 0.5%, 1%, 2%, 5%, and 10% were prepared and solution pH, EP, and water potential measured. To test affects on germination, pollen was placed on agar germination media in petri dishes and then treated with 10: l of chemical solution. Percentage pollen germination and tube growth was calculated 4, 12, and 24 h after treatment. Excised pistils from forced flowers were placed on glass filter papers saturated with chemical solution. Pistil damage was visually, subjectively rated for damage indicated by discoloration 24 h aft...
HortScience
As funding directed toward research has diminished, it has become vital seek other avenues of sup... more As funding directed toward research has diminished, it has become vital seek other avenues of support to maintain long term field projects. To meet this need, the University of Arkansas Horticulture Department began the Friends of Fruit (FOF) program during 2004 engaging volunteers in conducting tree fruit field research. Volunteers were graduates of the Master Gardener program and executed tasks including data collection and plot maintenance. Objectives of this study were to evaluate the experiences and benefits to the volunteers and horticulture department, and to assess the success of the FOF program in providing assistance and support to research. All volunteers and facilitators were interviewed. Interview questions were designed to understand the motivation and level of volunteer activity, determine if training and supervision was adequate, and determine if ample recognition occurred. Volunteers sought experience and knowledge with fruit crops. Costs to volunteers included time...
HortScience
The genus Betula consists of approximately 50 deciduous species throughout northern hemisphere. N... more The genus Betula consists of approximately 50 deciduous species throughout northern hemisphere. Net CO2 assimilation ([A]) of four birch taxa (Betula alleghaniensis Britton, B. davurica Pall., B. nigra L. `Heritage', and B. papyrifera Marsh.) was measured with a portable gas exchange system, CIRAS-I. Light was increased from 0 to 2000 μmol· m-2·s-1 at increments of 25, 50, 100, 250, 500, 750, 1000, 1250, 1500, 1750, 2000 μmol·m–2·s–1 to create an [A] light-response curve. CO2 concentration was gradually increased to 1100 ppm in increments 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100 ppm to create an [A]-Ca (ambient CO2) curve. B. davurica had significantly higher potential A capacity than the other taxa under high CO2 conditions. Betula nigra `Heritage' had the highest carboxylation efficiency among four taxa. B. davurica and B. nigra `Heritage', had higher [A] when ambient CO2 is 0ppm. Betula davurica and B. nigra `Heritage', had higher light-saturate...
HortScience
Higher education curricula should be alert to trends in production and science, and responsive to... more Higher education curricula should be alert to trends in production and science, and responsive to needs of producers and consumers in our society. A recent trend has emerged nationally and internationally for the production and consumption of certified organic produce which is increasing at a significant rate. Following the creation of the National Organic Program and formal federal regulations for certification which govern production, it has been questioned whether horticulture programs in land grant institutions have adjusted curricula appropriately to train producers, consultants, extension specialists, teachers and research scientists to be engaged in organic production systems. According to USDA statistics, several states in the southern region have significantly fewer certified organic farms and certifying agencies than the northeast, Midwest or western regions. A review horticulture and crops programs at 36 land grant universities (1862 and 1890) in 14 southern region states...
HortTechnology
Extending the production season of blackberry (Rubus subgenus Rubus) cultivars allows producers t... more Extending the production season of blackberry (Rubus subgenus Rubus) cultivars allows producers the opportunity to potentially receive better prices. Producers could benefit from out-of-season production by sustaining cash flow during more of the year and thereby expanding their market. The objective of this study was to compare the present value (PV) probabilities of being able to cover the total cost (TC) of production (break-even) for open-field and high tunnel production systems for the primocane-fruiting blackberry cultivar Prime-Jan® in northwestern Arkansas. (PVs) of gross revenues (GRs) of each production system were simulated 500 times. Total yields were higher in the open-field system in the first 2 years of production and consistently higher in weeks 33 to 34 and 36 to 37 than high tunnel production. It seems that there are no yield benefits from the high tunnel system early in the harvest season, except in the first year of primocane-fruiting production. The break-even p...
HortScience
The relationship of variability in flowering and fruiting habit to canopy position and changing d... more The relationship of variability in flowering and fruiting habit to canopy position and changing diurnal light and photosynthetic pattern was examined in 7 mature spur-type `Red Delicious'/MM106 apple trees. A .5×.5m column was placed in the north, south, east and west sections of tree canopies. Columns were subdivided by height with 3 study areas located at .25-.5m, 1.0-1.25m and 1.75-2.0m from the top of the canopy. In each, section, flowering index, fruit set, individual fruit weight and size, skin coloration, fruit soluble solids content, spur leaf area and spur bud diameter were determined. Photosynthetically active radiation and photosynthesis were measured from bloom through harvest correlated with variability in flowering, fruiting, spur quality and distribution of growth.
HortScience
Twelve apple orchards and an experimental orchard were evaluated in 2 years for weed population a... more Twelve apple orchards and an experimental orchard were evaluated in 2 years for weed population and diversity, primary pests (codling moth, oriental fruit moth, plum curculio and mites), primary diseases, soil water content, and 37 horticultural attributes describing tree growth, fruit growth, productivity, tree nutrition, and management intensity. Data were collected at 2 week intervals. The experimental orchard contained three apple cultivars grown in three orchard floor management systems. Increased weed ground cover related to earlier and increased mite predator populations in trees, decreased pest mite-days, but reduced tree and fruit growth. Grass weed species appeared more detrimental to tree growth than broadleaf species. Tree training intensity was negatively related to canopy density, and incidence of pests and diseases. Reductions in fruit size and quality were more closely linked to weed competition, and earliness and degree of pest mite infestation than to crop load.
HortScience
Summer pruning effects on processing peach on fruit quality, light penetration and interception, ... more Summer pruning effects on processing peach on fruit quality, light penetration and interception, and % defects was studied in 2 trials. In study A, pillar-trained trees were pruned with the following treatments: a control, summer pruning at stage II fruit growth, summer pruning post-harvest or, pruning twice (all trees dormant pruned). In the first year, pruning prior to harvest significantly increased blush and flesh firmness but reduced soluble solids content (SSC). In the second year, summer pruning reduced yield per tree and fruit drop (weight and % of total) but did not affect fruit size, blush, or SSC. After 2 years, trees pruned post-harvest or twice had significantly smaller height, spread and trunk diameter.1 In study B, 2 cultivars of central leader trained trees were pruned at stage II fruit growth in the following treatments: a control, canopy thinning, and hedging. Thinning pruning improved light penetration and hedging reduced light interception. Thinning pruning reduc...
HortScience
Ethrel sprays were applied at 50 or 100 ppm at approximately 40%, 70% leaf fall (10/16/89 or 10/2... more Ethrel sprays were applied at 50 or 100 ppm at approximately 40%, 70% leaf fall (10/16/89 or 10/24/89, respectively) or at both times on `Redhaven' and `Allgold' peaches. Bud hardiness was determined biweekly by differential thermal analysis (DTA). Stage and percentage of bloom open during the bloom period were subjectively estimated.Spraying trees with 100ppm Ethrel at 50% leaf fall significantly increased bud hardiness at mid-winter compared to other treatments. After a mid-winter freeze (-21.7 C on 12/21/89), there was no significant difference between % bud survival of any treatments. But, trees treated with 50 or 100ppm Ethrel had 10-20% better bud survival than other treatments. Buds of the 2 cultivars had statistically similar hardiness although DTA analysis indicated that Redhaven had a .5-.8 C lower freezing point than Allgold in mid winter. This trend was reversed close to bloom with Allgold having .7 C lower freezing point than Redhaven. The time of full bloom was...
HortScience, 1994
Three studies were established to compare spring (S) vs. autumn (F) N fertilizer applications on ... more Three studies were established to compare spring (S) vs. autumn (F) N fertilizer applications on apple tree performance. The studies used newly planted trees, 4-yr-old trees, and 8-yr-old trees, fertilized with either ammonium nitrate or urea at 2 weeks after harvest (F) or at bud break (S). In the first 3 years growth in a newly planted orchard, time of fertilizer did not significantly affect tree height or TCSA. In the first cropping year, F fertilized trees had the greatest flower cluster number and bloom density but similar % set and yield compared to S fertilized trees. F fertilized trees in mature orchards studies tended to be shorter and have smaller TCSA increment after 3 yrs. Treatments did not affect bloom density, % set or total yield although spring fertilized trees had a greater % drop. Although spur leaves of F fertilized trees had greater N content at bloom, shoot leaves typically had lower N and Mn, and higher P, K, and Ca at 90 days after bloom compared to S treatme...
HortScience, 2005
Japanese beetle (Popilla japonica Newman) has caused severe damage on a wide range of horticultur... more Japanese beetle (Popilla japonica Newman) has caused severe damage on a wide range of horticultural crops since its first introduction to the Eastern United States from Japan in 1916. Leaves are skeletonized by adult beetles feeding in masses, which makes this insect damage easy to identify. In Arkansas, Japanese beetle was first trapped in Washington County in 1997 and has reached epidemic proportions in the most recent three years. Leaf skelotonization and feeding preference on eighteen birch accessions by Japanese beetle were recorded in 2003 and 2004. There was a wide range from no feeding (0% leaf skelotonization) to high feeding preference (89% leaf skelotonization). Betula utilis var. jacquemontii and B. papyrifera `Renaissance Upright' had highest preference. Betula pendula `Laciniata' had no feeding damage from Japanese beetle.
HortScience, 1991
Gas exchange (assimilation, transpiration, water use efficiency, and conductance) of `Shawnee'... more Gas exchange (assimilation, transpiration, water use efficiency, and conductance) of `Shawnee' blackberry were measured under field conditions with a portable system (ADC-IRGA with Parkinson Leaf Chamber). Gas exchange primocane pentifoliate leaflets were similar. Gas exchange rates of leaves along a cane exhibited a quadratic function of leaf position with leaves in lower-mid sections (relative position 0.3 - 0.5) having higher A, TR, WUE, gs than either basal or apical leaves. Leaves subtending fruiting laterals on fruiticanes had higher assimilation than similar age leaves on primocanes but did not differ in Tr, WUE, or gs. Primocanes had estimated dark respiration rates of 0.33mg·dm-1.hr-1, estimated light compensation at 14-20 mol.m-2.s-1, estimated light saturation at 1000-1100 mol.m-2.s-1 with maximum A rates ranging from 24-30 mg CO2.dm-1.hr-1. Measurements were made at field temperatures ranging from 24-35 C. Although temperature response was not measured, correlation i...
Soil Science, 2009
In the early 1900s, northwest Arkansas was the leading apple (Malus sylvestris Mill.)-producing r... more In the early 1900s, northwest Arkansas was the leading apple (Malus sylvestris Mill.)-producing region in the United States. To maximize yields and quality, apple producers used heavy doses of lead (Pb) arsenate at the time to control agricultural pests, particularly the codling moth (Cydia [Laspeyresia] pomonella). Northwest Arkansas is a region underlain by karst geology, specifically fractured limestone and dolomitic bedrock, which creates the potential for rapid downward transport of surface contaminants, such as arsenic (As) from past Pb arsenate usage in the region, to the groundwater. Northwest Arkansas is also presently one of the most rapidly expanding regions in the United States in terms of urbanization and population. Thus, it is critical that high-quality surface and groundwater resources are maintained as potable water sources. The objective of this study was to evaluate the effect of land use (i.e., historic apple orchard, broiler litterYamended pasture, historic orchard-followed-by-broiler-litter-amended pasture, and nonorchard/nonlittered land use) and soil depth (i.e., 0Y2, 2Y4, and 4Y8 cm) on acid-recoverable soil As, Pb, and phosphorus. Soil As concentrations were lowest in the 0-to 2-and/or 2-to 4-cm depth and increased with depth in all land uses, expect for the litter-only pastureland, in which soil As concentrations did not differ among soil depths. Soil Pb concentrations also increased with depth, but only in the orchard-followed-by-litter-amended pasture. Soil As and Pb concentrations were at least numerically greater in all soil depths in the orchardfollowed-by-litter-amended pasture than in all other land use/soil depth combinations. Soil phosphorus concentrations were greater at all depths in the land uses that received broiler litter than in those land uses that did not and decreased with depth in all land uses. The results of this study indicate that historic Pb arsenate usage seems to be more responsible for elevated soil As concentrations than even decades of annual land application of As-containing broiler litter to pasturelands that had never received Pb arsenate applications for pest control during apple production.
Acta Horticulturae, 1990
... 217. Rom, CR, and Ferree, DC, 1984. Spur leaf characteristics of nine apple cultivars. Fruit ... more ... 217. Rom, CR, and Ferree, DC, 1984. Spur leaf characteristics of nine apple cultivars. Fruit Var. J. 38:2-5. Table 3 - The influence of limb orientation on spur development of 'Delicious' apple. Spur Leaves Spurs per Specific Dry Bud Limb Area Leaf Wt. Wt. Dia. ...
Physiologia Plantarum, 1988
HortScience
The role of spur leaves in bud and fruit development on two spur-type `Delicious' apple strai... more The role of spur leaves in bud and fruit development on two spur-type `Delicious' apple strains (Malus domestica Borkh.) and factors affecting spur development were studied. Reducing spur leaf area on vegetative spurs in August reduced the number of spurs that flowered the following year but did not affect flower size. On spurs that did flower, leaf area reduction the previous year did not influence leaf number or area, but the bourse shoot leaf area was reduced. Spur bud diameter, leaf area, size, specific leaf weight (SLW), and leaf dry weight were larger on 2-year-old vegetative spurs than on 1- or 3-year-old spurs. Within each age section of a limb, spur leaf number, area, size, SLW, and bud diameter decreased from the apical to basal positions on the limb. Flower number did not vary within a limb section, but fruit set was lower on the most apical and basal spurs compared to midshoot spurs. Fruit size was largest at the apical end of each limb section and was smallest at ba...
HortScience
Light distribution in two cultivars on three dwarfing rootstocks in three high-density apple tree... more Light distribution in two cultivars on three dwarfing rootstocks in three high-density apple tree training systems was measured in the sixth leaf beginning at full bloom and continuing through the season. Training system had a significant effect on light penetration into the lowest point of the canopy (measured at 0.5 m), with the slender spindle being significantly darker than either the central leader or the vertical axis, although all three systems were below the threshold value of 30% full sun (FS) needed to maintain productivity for most of the season. Cultivar had no significant effect; however, trees of both `Jonagold' and `Empire' fell below 20% FS early in the season and remained there until late in the season. Rootstock had the greatest effect, with trees on M9 and M26 being significantly darker in the lower canopy than trees on Mark. Trees on M26 and M9 fell below 10% FS early in the season and remained there, while trees on Mark never fell below 20% FS.
HortScience
The NE-183 project was established in 1993 and the first trial planted in 1995 with the objective... more The NE-183 project was established in 1993 and the first trial planted in 1995 with the objective of evaluating new apple cultivars for horticultural, pest and disease resistance, and qualitative characteristics. Arkansas (AR) is the southernmost location for the initial planting. The following cultivars are in AR trial: `Arlet', `Braeburn', `Cameo', `Creston', `Enterprise', `Fortune', `Fuji', `Gala Supreme', `Ginger Gold', `GoldCrisp', `Golden Delicious', `Golden Supreme', `Goldrush', `Honeycrisp', `NY75414-1', `Orin', `Pristine', `Sansa', `Shizuka', `Suncrisp', `Sunrise', and `Yataka'. Bloom of `Braeburn', `Yataka', `Orin', `Gold Supreme', `Fortune', and `Enterprise' were early and may be exposed to annual spring frosts. The following cultivars ripened in July or August and may be too early for southern markets: `Pristine', `Sunrise', `Sansa', `Ginger Gold...
HortScience
Apple cultivar development is an important program necessary to sustain the existing fruit indust... more Apple cultivar development is an important program necessary to sustain the existing fruit industry and stimulate new production systems for Arkansas and the region. The cultivar development program has two parts. First, currently available cultivars are tested with multiple trees for multiple years. Second, about 150 advanced selections from the Arkansas apple breeding program are evaluated in trials with multiple trees (2nd test) and in replicated trials (3rd test). The goal of both programs is to identify cultivars that have potential in the local production systems and for Arkansas' markets, and to identify those cultivars which are not adapted to the region. All cultivars and advanced selections are evaluated for ∂35 qualitative and quantitative characteristics, including time of bloom, time of harvest, length of harvest season, fruit aesthetic and internal quality, environmental adaptability especially to heat and high light, and insect and disease susceptibility. Primary ...
HortScience
Alternate bloom thinners are needed for apple are needed to replace compounds which can no longer... more Alternate bloom thinners are needed for apple are needed to replace compounds which can no longer be used or have production system limitations. The effects of 24 chemicals selected as osmotic agents, organic acids, oils, essential oils, or potential metabolic agents and their properties of pH, electrical potential (EP) and water potential were tested in vitro on `Gala' apple pollen germination, tube growth and pistil damage. Solution concentrations of 0%, 0.25%, 0.5%, 1%, 2%, 5%, and 10% were prepared and solution pH, EP, and water potential measured. To test affects on germination, pollen was placed on agar germination media in petri dishes and then treated with 10: l of chemical solution. Percentage pollen germination and tube growth was calculated 4, 12, and 24 h after treatment. Excised pistils from forced flowers were placed on glass filter papers saturated with chemical solution. Pistil damage was visually, subjectively rated for damage indicated by discoloration 24 h aft...
HortScience
As funding directed toward research has diminished, it has become vital seek other avenues of sup... more As funding directed toward research has diminished, it has become vital seek other avenues of support to maintain long term field projects. To meet this need, the University of Arkansas Horticulture Department began the Friends of Fruit (FOF) program during 2004 engaging volunteers in conducting tree fruit field research. Volunteers were graduates of the Master Gardener program and executed tasks including data collection and plot maintenance. Objectives of this study were to evaluate the experiences and benefits to the volunteers and horticulture department, and to assess the success of the FOF program in providing assistance and support to research. All volunteers and facilitators were interviewed. Interview questions were designed to understand the motivation and level of volunteer activity, determine if training and supervision was adequate, and determine if ample recognition occurred. Volunteers sought experience and knowledge with fruit crops. Costs to volunteers included time...
HortScience
The genus Betula consists of approximately 50 deciduous species throughout northern hemisphere. N... more The genus Betula consists of approximately 50 deciduous species throughout northern hemisphere. Net CO2 assimilation ([A]) of four birch taxa (Betula alleghaniensis Britton, B. davurica Pall., B. nigra L. `Heritage', and B. papyrifera Marsh.) was measured with a portable gas exchange system, CIRAS-I. Light was increased from 0 to 2000 μmol· m-2·s-1 at increments of 25, 50, 100, 250, 500, 750, 1000, 1250, 1500, 1750, 2000 μmol·m–2·s–1 to create an [A] light-response curve. CO2 concentration was gradually increased to 1100 ppm in increments 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100 ppm to create an [A]-Ca (ambient CO2) curve. B. davurica had significantly higher potential A capacity than the other taxa under high CO2 conditions. Betula nigra `Heritage' had the highest carboxylation efficiency among four taxa. B. davurica and B. nigra `Heritage', had higher [A] when ambient CO2 is 0ppm. Betula davurica and B. nigra `Heritage', had higher light-saturate...
HortScience
Higher education curricula should be alert to trends in production and science, and responsive to... more Higher education curricula should be alert to trends in production and science, and responsive to needs of producers and consumers in our society. A recent trend has emerged nationally and internationally for the production and consumption of certified organic produce which is increasing at a significant rate. Following the creation of the National Organic Program and formal federal regulations for certification which govern production, it has been questioned whether horticulture programs in land grant institutions have adjusted curricula appropriately to train producers, consultants, extension specialists, teachers and research scientists to be engaged in organic production systems. According to USDA statistics, several states in the southern region have significantly fewer certified organic farms and certifying agencies than the northeast, Midwest or western regions. A review horticulture and crops programs at 36 land grant universities (1862 and 1890) in 14 southern region states...
HortTechnology
Extending the production season of blackberry (Rubus subgenus Rubus) cultivars allows producers t... more Extending the production season of blackberry (Rubus subgenus Rubus) cultivars allows producers the opportunity to potentially receive better prices. Producers could benefit from out-of-season production by sustaining cash flow during more of the year and thereby expanding their market. The objective of this study was to compare the present value (PV) probabilities of being able to cover the total cost (TC) of production (break-even) for open-field and high tunnel production systems for the primocane-fruiting blackberry cultivar Prime-Jan® in northwestern Arkansas. (PVs) of gross revenues (GRs) of each production system were simulated 500 times. Total yields were higher in the open-field system in the first 2 years of production and consistently higher in weeks 33 to 34 and 36 to 37 than high tunnel production. It seems that there are no yield benefits from the high tunnel system early in the harvest season, except in the first year of primocane-fruiting production. The break-even p...
HortScience
The relationship of variability in flowering and fruiting habit to canopy position and changing d... more The relationship of variability in flowering and fruiting habit to canopy position and changing diurnal light and photosynthetic pattern was examined in 7 mature spur-type `Red Delicious'/MM106 apple trees. A .5×.5m column was placed in the north, south, east and west sections of tree canopies. Columns were subdivided by height with 3 study areas located at .25-.5m, 1.0-1.25m and 1.75-2.0m from the top of the canopy. In each, section, flowering index, fruit set, individual fruit weight and size, skin coloration, fruit soluble solids content, spur leaf area and spur bud diameter were determined. Photosynthetically active radiation and photosynthesis were measured from bloom through harvest correlated with variability in flowering, fruiting, spur quality and distribution of growth.
HortScience
Twelve apple orchards and an experimental orchard were evaluated in 2 years for weed population a... more Twelve apple orchards and an experimental orchard were evaluated in 2 years for weed population and diversity, primary pests (codling moth, oriental fruit moth, plum curculio and mites), primary diseases, soil water content, and 37 horticultural attributes describing tree growth, fruit growth, productivity, tree nutrition, and management intensity. Data were collected at 2 week intervals. The experimental orchard contained three apple cultivars grown in three orchard floor management systems. Increased weed ground cover related to earlier and increased mite predator populations in trees, decreased pest mite-days, but reduced tree and fruit growth. Grass weed species appeared more detrimental to tree growth than broadleaf species. Tree training intensity was negatively related to canopy density, and incidence of pests and diseases. Reductions in fruit size and quality were more closely linked to weed competition, and earliness and degree of pest mite infestation than to crop load.
HortScience
Summer pruning effects on processing peach on fruit quality, light penetration and interception, ... more Summer pruning effects on processing peach on fruit quality, light penetration and interception, and % defects was studied in 2 trials. In study A, pillar-trained trees were pruned with the following treatments: a control, summer pruning at stage II fruit growth, summer pruning post-harvest or, pruning twice (all trees dormant pruned). In the first year, pruning prior to harvest significantly increased blush and flesh firmness but reduced soluble solids content (SSC). In the second year, summer pruning reduced yield per tree and fruit drop (weight and % of total) but did not affect fruit size, blush, or SSC. After 2 years, trees pruned post-harvest or twice had significantly smaller height, spread and trunk diameter.1 In study B, 2 cultivars of central leader trained trees were pruned at stage II fruit growth in the following treatments: a control, canopy thinning, and hedging. Thinning pruning improved light penetration and hedging reduced light interception. Thinning pruning reduc...
HortScience
Ethrel sprays were applied at 50 or 100 ppm at approximately 40%, 70% leaf fall (10/16/89 or 10/2... more Ethrel sprays were applied at 50 or 100 ppm at approximately 40%, 70% leaf fall (10/16/89 or 10/24/89, respectively) or at both times on `Redhaven' and `Allgold' peaches. Bud hardiness was determined biweekly by differential thermal analysis (DTA). Stage and percentage of bloom open during the bloom period were subjectively estimated.Spraying trees with 100ppm Ethrel at 50% leaf fall significantly increased bud hardiness at mid-winter compared to other treatments. After a mid-winter freeze (-21.7 C on 12/21/89), there was no significant difference between % bud survival of any treatments. But, trees treated with 50 or 100ppm Ethrel had 10-20% better bud survival than other treatments. Buds of the 2 cultivars had statistically similar hardiness although DTA analysis indicated that Redhaven had a .5-.8 C lower freezing point than Allgold in mid winter. This trend was reversed close to bloom with Allgold having .7 C lower freezing point than Redhaven. The time of full bloom was...