bluuebunny/crossref_metadata_2025 huggingface dataset:
Postharvest Quality of `Thompson Seedless' Grapes after Insecticidal Controlled Atmosphere Treatments
Authors: Ahumada Miguel H. , Mitcham Elizabeth J. , Moore Denise G.
Published: February 2019

Nonfumigated `Thompson Seedless' table grapes were stored in air or one of four atmospheres: 0.5% O2 and 35% CO2; 0.5% O2 and 45% CO2; 0.5% O2 and 55% CO2; and 100% CO2. Grapes were stored at 5C and 20C for 6 and 4.5 days, respectively. The fruit were evaluated for weight loss, berry firmness, soluble solids, titratable acidity, berry shattering, rachis browning, berry browning, and volatiles (acetaldehyde and ethanol). Fruit quality was not affected at 5C; however, at 20C, controlled atmosphere (CA) treatments had a detrimental effect on rachis browning and soluble solids. CA at both temperatures induced the production of high levels of acetaldehyde and ethanol. After treatment at 5C, volatile concentrations were two-thirds lower than at 20C. A consumer taste panel evaluated fruit 3 days after removal from CA. Consumer preference was negatively affected by the CA treatments at 20C; however at 5C, consumer preferencewas not affected by the treatments. Preliminary data for mortality of Omnivorous Leafroller pupae (Platynota stultana), Western Flower Thrips adults (Frankliniella occidentalis), and Pacific Spider Mite adults (Tetranychus pacificus) indicate that many of these treatments would provide quarantine security.
Early Performance of Four Apple Cultivars on Mark and M.26 Rootstocks
Authors: Schupp James R.
Published: February 2019

To evaluate the interactions between cultivar and rootstock, four apple (Malus domestica Borkh.) cultivars, `Pioneer Mac', `Marshall McIntosh', `Ginger Gold', and `Empire' on two rootstocks, M.26 and Mark, were planted in a split-plot design. After 5 years, `Pioneer Mac' and `Ginger Gold' had larger trunk cross-sectional area (TCSA) on M.26 than on Mark. `Marshall McIntosh' and `Empire' had larger TCSA on Mark than on M.26. Precocity, expressed as both number of flower clusters and yield, was greater for trees on Mark for all cultivars except `Ginger Gold', which had greater flower cluster numbers and yield on M.26. Fruit size was variable from year to year, depending on crop load; however, `Pioneer Mac' and `Ginger Gold' usually produced the largest fruit, while `Empire' consistently produced the smallest fruit—'Ginger Gold' appears to be incompatible on Mark. The results of this study demonstrate that cultivar × rootstock interactions can be significant and need to be considered when rootstock and planting density recommendations are made.
Mystery Spot of `Enterprise' Apples Appears to Be a Low-calcium Disorder
Authors: Greene George M.
Published: February 2019

The apple cultivar Enterprise is a product of the Purdue–Rutgers–Illinois (PRI) disease-resistant apple breeding program. It has field immunity to apple scab, has a high level of resistance to cedar apple rust and fire blight, and is moderately resistant to apple powdery mildew. This resistance to these diseases makes the production of this cultivar desirable, especially on the popular fire blight-susceptible M.26 rootstock. Compared to many other scab-resistant cultivars, `Enterprise' has performed well in the mid-Atlantic area. However, this cultivar has been reported to be susceptible to low-Ca disorders when grown in New Jersey and Virginia. The mid-Atlantic area is notorious for the production of fruit with high levels of corking and bitter pit. This may be due to factors such as vigorous tree growth and low transpirational flow, which may be weather-related. Circumstantial evidence based on the production of clean `Enterprise' at Biglerville, Pa., where moderately high rates of CaCl2 have been applied in cover sprays, indicate that this disorder may be a Ca deficiency symptom. A replicated trial of many scab-resistant cultivars was established in 1990, 1991, and 1992. Due to the common incidence of low-Ca disorders, CaCl2 has been added to the cover spray program that is applied for insect control. Low-Ca disorders have never been seen in fruit produced at Biglerville, and the cover spray program applied 67 and 73 kg·ha–1 of CaCl2 (77% to 80% CaCl2, flake) in 1993 and 1994, respectively.
Performance of Arizona and California Guayule Lines in Southern Texas
Authors: Latigo G.V. , Smart J , Bradford J.O. , Kuti J.O.
Published: February 2019

Guayule (Parthenium argentatum Gray) is a promising alternative to (Hevea brasiliensis Muell. Arg.) for rubber production in semiarid regions. Substantial improvement in yield is needed to establish guayule as a competitive source of natural rubber. A 4-year field study was conducted on a dryland site in southern Texas to evaluate productivity of selected guayule breeding lines from Arizona and California. Plants were harvested at the age of 22, 34, and 46 months and analyzed for dry weight, resin content, rubber content, resin yield, rubber yield, and percent mortality. While significant differences (P = 0.05) were found for dry weight, resin content, and rubber content within the harvest dates and among the guayule lines, no significant differences were found for rubber content between the harvest dates for each genotypes. Phytomass was highly correlated (r = 0.94) with rubber yield. Survivorship of all the guayule lines decreased progressively over the experimental period and mortality rates ranged from 38% to 67 %. Guayule lines `UC102' from California and `N6-5' and `P3-1' from Arizona were ranked highest for all traits measured.
Breeding Lettuce for Big Vein Resistance
Authors: Ryder Edward J. , Robinson Bert J.
Published: February 2019

Big vein is a disease of lettuce; symptoms include vein clearing and delayed head formation. Big vein virus is vectored by a fungus that inhabits lettuce roots. We developed a greenhouse screening procedure to evaluate cultivars and breeding materials for resistance, which is relative and based on the proportion of plants in a population that show no symptoms at an arbitrary time after inoculation. We have screened 744 cultivars in preliminary tests. Of these, 49 showed promise for resistance. Eleven of the promising cultivars showed consistent resistance in replicated greenhouse and field trials. In breeding populations, reaction of single plants is not as reliable an indicator of resistance as the reaction of plant groups. Therefore, F3 families are more useful than the F2 for screening. Field test rankings of materials selected with this method are consistent with greenhouse evaluations.
Deficit Irrigation in `Braeburn' Apples: Fruit Water Relations and Plant Growth
Authors: Mills Tessa M. , Behboudian M. Hossein , Clothier Brent E.
Published: February 2019

Information on fruit water relations is scant for apple trees, especially under deficit irrigation. Here we discuss plant and fruit responses to deficit irrigation. Three-year-old potted `Braeburn' trees were studied in a glasshouse. The treatments were: well-watered control (C), early deficit (D1), and late deficit (D2). The latter two were, respectively, water stressed during 61–183 and 109–183 days after full bloom (DAFB). The final harvest was at 183 DAFB. Photosynthesis, stomatal conductance, and trunk circumference were lower in D1 and D2 than in C. Leaf area and shoot growth was reduced only in D1. Root length remained the same for all treatments. Fruit were smaller in D1 than in C; however, fruit growth was less sensitive to deficit irrigation than was vegetative growth. Fruit growth in D2 was the same as in C. Fruit concentrations of K+, fructose, sorbitol, total sugars, and titratable acidity were higher in D1 than in D2 and C. Total soluble solids were higher in D1 and D2 than in C. Although fruit water potential was lower in D1 than in C, a concomitant lowering of osmotic potential in D1 fruit led to maintenance of turgor potential, indicating osmotic adjustment. This could have been effected, at least partially, through accumulation of K+ and soluble sugars. Water relations of D2 fruit were not affected by deficit irrigation, although leaf water potential was lower than in C. Fruit water relations and fruit growth are therefore less sensitive to deficit irrigation than are those of vegetative parts.
Effects of Irrigation with Reclaimed Water on Citrus Tree Performance
Authors: Parsons Larry R. , Wheaton T. Adair
Published: February 2019

`Hamlin' oranges and `Orlando' tangelos on four rootstocks have been irrigated since planting in 1987 with highly treated reclaimed effluent water at application rates of ≈500, 1250, and 2500 mm/year. Reclaimed water treatments have been compared to a well water control at 500 mm/year. Tree growth, yield, and fruit quality have been satisfactory for all irrigation treatments. Growth and yield of `Orlando' tangelos was greatest at the 2500 mm rate and yield was highest on `Swingle' citrumelo and `Carrizo' citrange rootstocks. `Orlando' tangelos benefited more from the high irrigation rates than `Hamlin' oranges. Dilution of soluble solids in the juice by high irrigation rates has diminished as trees matured. Leaf nutrient content was influenced by irrigation, variety, and rootstock. Reclaimed water supplied all the phosphorous and boron needed for citrus production. Soil pH increased due to irrigation with reclaimed water. No disease problems have resulted from the high irrigation rates. Irrigation with high rates of reclaimed water on deep well-drained sands is not detrimental and has benefited citrus production.
Nitrate-Nitrogen Concentrations in the Soil Profiles Beneath Containerized Rhododendron Provided High or Low Irrigation Volumes
Authors: Colangelo David J. , Brand Mark H.
Published: February 2019

Uniform Rhododendron `Roseum Elegans' plants were potted into 3-gal plastic containers and place atop eight identical 1-m3 soil-filled boxes (six per box). The bottomless boxes were recessed into a grassed field and filled with Woodbridge fine sandy loam. Soil samples were taken in 30-cm layers to 90 cm from each box and analyzed for NO3-N. Samples were taken at 14-day intervals from 9 June 1994 to 10 Nov. 1994. All plants received 40 g of Sierrablen 17N–6P–10K 8–9 month controlled-release fertilizer as a topdressing on 13 June 1994. Half of the boxes received a high irrigation rate of 5 gal/min for 4 min and half received a low rate of 5 gal/min for 1 min. Irrigation was provided every other day from above the plant canopy to simulate typical irrigation practices. For the low irrigation treatment, NO3-N levels reached 19.5 mg of NO3-N/kg of soil in the first 28 days of the study, while increases in the deeper layers lagged behind. For the high treatment, NO3-N levels followed a similar pattern, but only reached 8.9 mg of NO3-N/kg of soil in the same time period. These results suggest that the high irrigation volumes cause NO3-N to leach at a faster rate, posing a threat to water resources.
Blueberry Production in a High-density, Evergreen System
Authors: Reeder R.K. , Darnell R.L. , Obreza T.A.
Published: February 2019

Blueberry plants fertilized at 3-week intervals with nitrogen (N) throughout the year and protected from freezing temperatures avoid dormancy and produce an off-season “winter” crop. Southwestern Florida offers a climate where this production system can be implemented without undue fear of freezes. `Sharpblue', `Gulfcoast', and `Warmabe' southern highbush blueberry cultivars have been planted at high density (10,000 plants/ha) to determine the feasibility of successfully establishing an evergreen production system for blueberry. Three rates of N fertilization (84, 168, and 252 kg·ha–1) and the use of peat or municipal solid waste (MSW) compost as soil amendments are being evaluated in this study. Initial data on plant growth indicate that, during the first 9 months of the planting, 168 kg N/ha will produce plants similar in height, but with significantly less volume, to those receiving 252 kg N/ha. MSW compost appears to be a beneficial soil amendment for blueberry establishment despite an increase in soil pH associated with the compost amendment.
Preemergence Weed Control with Sulfentrazone (F 9285) and Sulfentrazone Combinations in Field-grown Ornamentals
Authors: Crotser Michael P. , Weston Leslie A. , McNiel Robert
Published: February 2019

Sulfentrazone is a promising new herbicide now under evaluation for use in agronomic and ornamental cropping systems. Sulfentrazone selectively controls yellow nutsedge, morningglories, and other annual grasses and broadleaf weeds. Research was conducted to evaluate the efficacy of sulfentrazone in combination with other labeled products for preemergence weed control in nursery crops. Treatments included sulfentrazone at 0.56 and 1.12 kg a.i./ha and sulfentrazone at 0.37 kg a.i./ha in combination with the following; dithiopyr at 0.37 kg, oxyfluorfen at 0.56 kg, metolachlor at 3.36 kg, isoxaben at 0.56 kg, norfluorazon at 2.64 kg, and isoxaben plus oryzalin at 2.24 kg a.i./ha. Combinations of sulfentrazone with isoxaben or metolachlor provided superior control of morningglory spp., honeyvine milkweed, Carolina horsenettle, and yellow nutsedge. Sulfentrazone plus oxyfluorfen or isoxaben plus oryzalin also provided good control. Poorest overall control was obtained with sulfentrazone plus dithiopyr. Viburnum and deciduous holly were slightly injured 4 WAT with sulfentrazone plus metolachlor. Sulfentrazone plus dithiopyr treatments resulted in serious injury to burning bush 4 WAT and slight injury at 8 WAT.
Orchard Groundcover Management Systems Influence Surface Runoff and Subsoil Leaching of Agrichemicals
Authors: Merwin Ian A. , Steenhuis Tammo S. , Ray John A.
Published: February 2019

Non-point source water pollution by agrichemicals is a recognized problem that has been studied in agronomic crop systems, and simulated using computer models or artificial soil columns, but rarely measured at field scale in orchards. For three growing seasons, we monitored the movement of nitrate and pesticide analogs and a widely used fungicide (benomyl) in two apple orchards under four different groundcover management systems (GMSs), including turfgrass, wood-chip mulch, residual pre-emergence herbicides, and post-emergence herbicide treatments. In subsoil lysimeter samplers at one orchard, we observed that nitrate and pesticide analogs leached more rapidly and in higher concentrations under herbicide plots compared with turfgrass plots. At another orchard where subsoil leaching and surface runoff of benomyl and nitrate-N were monitored in replicated GMS plots, we observed higher concentrations of benomyl (up to 30 μg·liter–1) and nitrate-N up to 50 μg·liter–1) leaching under herbicide GMS. The highest benomyl concentrations (375 μg·liter–1) and most frequent runoff of this pesticide were observed in the residual pre-emergence herbicide plots. Yearly weather patterns, irrigation, and development of different soil physical conditions under the four GMSs determined the relative magnitude and frequency of agrichemical leaching and runoff in both orchards. The agrichemicals apparently leached by mass flow in preferential flowpaths such as old root channels and soil cracks, while surface chemical runoff occurred mostly adsorbed on eroding soil sediment. These observations indicate that orchard GMSs can have a significant impact on leaching and runoff of pesticides and nutrients.
RNA Populations in Tomato Seeds Imbibing in the Presence or Absence of Abscisic Acid
Authors: Chohan Shahid N. , Brown Terence A.
Published: February 2019

The RNA content of tomato seeds was shown to increase when the seeds were imbibed in water. This increase was due mainly to an increase in nuclear RNA, the polysomal content declining and the ribonucleoprotein fraction remaining constant. The poly(A)+RNA population also showed a gradual increase, again due to a high de novo synthesis rate in the nucleus. In the presence of 200 μM abscisic acid (ABA), the total nuclear DNA failed to increase in the manner seen with water imbibition, leading to an overall decline in RNA during the first 1.5 h. The polysomal and ribonucleoprotein fractions were unaffected by ABA. The decline in total nuclear RNA was due primarily to a major decrease in the nuclear poly(A)+ content of seeds imbibing with ABA. This reduction in de novo transcription may be a factor responsible for the inhibitory effect that ABA has on germination of tomato seeds.
Effects of Enzyme Infusion on The Processing and Storage Quality of Peeled Citrus
Authors: Pao Steven , Petracek Peter D. , Brown G. Eldon
Published: February 2019

An enzymatic peeling process is currently used to produce peeled citrus fruit that are convenient for consumption. By this process, fruit are scored and infused with pectinase or pectinase and cellulase solution and are incubated at 20 to 45C for 0.5 to 2 h. While enzyme solution apparently weakens of the albedo and thus improves separation of the fruit from its peel, we expect that enzyme infused into the flesh reduces storage quality. In these studies, fruit were vacuum- or pressure-infused with or without pectinase in water. The time required to peel white `Marsh' and `Ruby Red' grapefruit infused with solution containing enzyme were only 10% to 20% less than for fruit infused with water alone. `Hamlin' orange and `Orlando' tangelo peeling times were not improved by enzyme treatment. This suggests that water is the primary operative component of the enzyme solution and that the enzyme is an active, but nonessential, supplement. For white grapefruit and oranges stored at 5, 10, 15, or 25C, nonenzyme-treated fruit had significantly less juice leakage than enzyme-treated fruit. For example, 0.2% and 5.0% of the peeled fruit weight was lost by non-enzymatically and enzymatically peeled fruit, respectively, for vacuum-infused oranges stored at 5C for 7 days. Moreover, the enzyme treatment significantly reduced firmness, as determined by a sensory panel. Microbial levels and rates of respiration and ethylene emanation during storage were not significantly affected by enzyme treatment. Similar results were found for vacuum- and pressure-infused fruit.
Growth Temperature Influences Postharvest Tolerance of Lemon Fruit to Hot Water, Cold, and Methyl Bromide
Authors: Houck Laurie G. , Jenner Joel F.
Published: February 2019

Lemon trees [Citrus limon (L.) Burm.[grown outdoors were moved into three greenhouses in Sept. 1993 before hot summer temperatures waned. Greenhouse (grh.) temperatures were 22 to 28C min./35 to 40C max. to maintain the hot growing condition effect. In late October, one grh. was set to 5 to 10C min./20C max. (cool), one to 20C min./33C max. (warm), and one to 25 to 30C min./35 to 40C max. (hot). Fruit was harvested after 1-, 2-, and 4-week exposures. Postharvest treatments applied 1 day after pick were hot water immersion (HWI) (55C/5 min.), cold (CT) (2C/3 weeks), or methyl bromide (MB) fumigation (60 g/m3/2 h/21C). Fruit was stored at 10C for 4 weeks after treatment and evaluated weekly. HWI caused more peel injury to fruit from cool (82%) and warm (60%) grhs. than from the hot grh. (32%). The incidence and severity of injuries increased with time fruit were held in the cooler grhs. CT caused more peel injury in fruit from the hot (94%) grh. than from the warm (48%) or cool (16%) grh. Severity of injury decreased with longer exposure in the cooler grhs. MB injury was least in fruit from the cool and warm grhs. (2% to 3%) and most from the hot grh. (14%). MB injury increased slightly with fruit age. In HWI, CT and MB tests `Eureka' fruit were injured more than `Lisbon'.
Elevated CO2 Atmosphere for Storage of Mature-green and Tree-ripe `Tommy Atkins' Mangoes
Authors: Bender R.J. , Brecht J.K.
Published: February 2019

Mangoes for long-distance markets are harvested at the mature-green stage and shipped in refrigerated containers. Shipment under controlled atmosphere is still tentative, and the CO2 concentrations used are relatively low (maximum 10%), although mangoes have been reported as being less-sensitive to elevated CO2 than other tropical fruits. In the present study, CO2 concentrations of 10%, 15%, 25%, 35%, and 45% combined with 5% O2 were used to store mangoes. Mature-green `Tommy Atkins' were stored for 21 days at 12C, followed by air storage at 20C for 5 days. Tree-ripe mangoes were stored at 8 or 12C under the same conditions. Ethanol production rates increased along with increasing CO2 concentrations. However, only 35% and 45% CO2 atmospheres inflicted damage. Color development was severely inhibited under those treatments. Lower CO2 treatments, up to 25% in the storage atmosphere, inhibited skin color development and ethylene biosynthesis but, after 5 days in air at 20C, skin color and ethylene production reached control levels. Fruit flesh firmness did not differ among treatments at 12C. Tree ripe mangoes stored in CA at 8C were only significantly firmer than control fruit at transfer from CA to air.
Bare-root Shade Tree Whip Production in Containers
Authors: Struve Daniel K.
Published: February 2019

A method is described for producing bare-root shade tree whips in containers. Whip production is begun in February in heated greenhouses by sowing seed. Seedlings are transplanted to copper-treated containers and grown in a greenhouse until May, when they are moved outdoors and transplanted to No. 3 copper-treated containers. In October (8 months after seeding), plant heights range from 1 to 2 m. Several media have been developed that result in rapid growth, while separating readily from the root system by hand-shaking. Bare-root plants placed in refrigerated storage for 6 months and repotted, retained high survival and regrowth potential. The system combines the handling ease of bare-root stock with the high survival and regrowth potential of container stock.
Constant Water Table: A New Technique for Hydroponic Lettuce Production
Authors: Buxton Jack W. , Jia Wenwei
Published: February 2019

Lettuce was produced using a new concept of hydroponics. The system is based on maintaining a constant water table (CWT). Plants grew on a flat surface and obtained the nutrient solution from capillary matting. One end of the mat was suspended in a trough containing the nutrient solution. The distance between the nutrient solution in the trough and the bench top was kept constant with a water level controller. The nutrient solution was resupplied from a larger reservoir. A ground cover on top of the capillary mat provided nutrient movement to the roots but prevented root penetration. Lettuce seedlings, germinated in small plug trays, were placed in holes cut in a 2.5-cm-thick styrofoam sheet. The styrofoam provided seedling support as well as protected the roots. Roots grew on the surface of the ground cover and were easily removed at harvest. The CWT could be adjusted by changing the height of the water level controller. The CWT concept of hydroponic production does not require pumps nor large storage reservoirs. No runoff occurs; the only nutrient solution used is that required by plants and a minimum amount of evaporation from the ground cover surface. Disease potential should be less than in other systems.
Meiotic Behavior and RAPD Segregation in a Tetraploid Hybrid (Vaccinium darrowi × V. corymbosum) Suggests Genomic Divergence in Blueberry
Authors: Vorsa Nicholi , Novy Richard
Published: February 2019

Vaccinium darrowi (D) is a wild blueberry species with low chilling requirements for budbreak, and heat and drought tolerance. Breeding efforts to incorporate these desirable traits into cultivated blueberry (V. corymbosum) (C) would be facilitated with a better understanding of the genomic homology between the two species. An interspecific tetraploid hybrid (CCDD, 2n=4x=48) was used to evaluate genome homology and interspecific recombination. Pollen mother cells examined at diakinesis and early metaphase I exhibited an average of 4.6 chain bivalents, 11.4 ring bivalents, 1.0 chain quadrivalent, and 3.0 ring quadrivalents. This data most closely fits a chromosome pairing model in which there is a greater pairing affinity between homologues than homoeologues. An analysis of the inheritance of 14 RAPD markers unique to V. darrowi in 72 backcross progeny of the V. darrowi–corymbosum hybrid also supported the pairing model: Seven of the 14 markers deviated significantly from tetrasomic inheritance ratios, expected if chromosome pairing was totally random. On the basis of the cytogenetic and RAPD analyses, the genomes of V. darrowi and V. corymbosum are divergent from one another, with preferential pairing within genomes. This outcome suggests there may be difficulty in breaking undesirable linkages when introgressing desirable traits from V. darrowi to V. corymbosum.
Nature of 2n Gamete Formation and Mode of Inheritance in Interspecific Hybrids of Diploid Vaccinium darrowii and Tetraploid V. corymbosum
Authors: Qu Luping , Hancock J.F.
Published: February 2019

RAPD markers were used to determine the level of heterozygosity transmitted via 2n gametes from V. darrowi cv. Florida 4b (Fla 4B) to interspecific hybrids with tetraploid V. corymbosum cv. Bluecrop. The tetraploid hybrid US 75 was found to contain 70.6% of Fla 4B's heterozygosity, a value consistent with a first division restitution (FDR) mode of 2n gamete production. Crossovers during 2n gamete formation were evidenced by the absence of 16 dominant alleles of Fla 4B in US 75, and direct tests of segregation in a diploid population involving Fla 4B. RAPD markers that were present in both Fla 4B and US 75 were used to determine the mode of inheritance in a segregating population of US 75 × V. corymbosum cv. Bluetta. More than 30 homozygous pairs of alleles were located that segregated in a 5:1 ratio, indicating US 75 undergoes tetrasomic inheritance.
Root Development in Sweet Corn Inoculated with the Biocontrol Fungus Trichoderma harzianum
Authors: Bjorkman Thomas , Harman Gary E. , Blanchard Lisa
Published: February 2019

Production of shrunken-2 sweet corn is often limited by poor establishment. Good root development is necessary for establishment, and it can be limited by stress or disease. Trichoderma harzianum strain 1295-22 was developed as a biocontrol fungus with particularly strong root-colonizing ability. In addition to acting as a biocontrol agent, it stimulates root growth. In greenhouse experiments using field soil, root dry weight 21 days after planting was 500 mg, greater compared with 320 mg in uninoculated controls, an average increase of >50%. The thoroughness of soil exploration more than doubled, from 31% (control) to 70% (Trichoderma) of the soil being within 1 cm of a root. The difference in performance was not attributable to disease: no disease symptoms were evident, the occurrence of disease organisms was low, it was the same in both treatments, and it was not associated with smaller plants. Furthermore, the greatest differences were noted in steam-sterilized soil. Colonization of the roots by Trichoderma was related to the age of the root. The oldest part of the radicle had 106 cfu/g root DW. Branched seminal roots had 105.5 cfu/g. Even the rapidly growing tips of the first-whorl roots were well-colonized (104.7 cfu/g). The mechanism of increased root growth has not been identified, but colonized roots acidify about 0.1 pH units more than control roots, which could cause both faster acid-growth and increased ion uptake. Ion leakage into distilled water is about 25% lower in colonized roots.
Electronic Sensing of Volatiles from Tomato Juice as a New Technology for Quality Control and Detection
Authors: Charles Denys J. , Hetzroni Amots , Simon James E.
Published: February 2019

Recent developments in electronic odor-sensing technology has opened the opportunity for non-destructive, rapid, and objective assessment of food quality. We have developed an electronic sensor (electronic sniffer) that measures aromatic volatiles that are naturally emitted by fruits and fruit products. The ability of our sniffer to detect contamination in fruit juice was tested using tomato juice as a model system. Tomato juice was extracted from cultivar Rutgers and divided into eight glass jars of 300 g juice each. The jars were divided into two treatments: the control jars contained tomato juice mixed with 0.15% sorbic acid to suppress microbial growth, and the experimental jars contained only tomato juice. All the jars were placed open, on a counter top in the laboratory for 8 days. The juice was tested daily with the electronic sniffer and for pH. The total volatiles in the headspace of the juice was extracted on alternating days via dynamic headspace method using charcoal traps, analyzed by gas chromatography, and confirmed by GC/mass spectometry. The results indicate that the sniffer is able to detect differences between the two treatments 4 days after the tomato juice was exposed to ambient atmosphere. The electronic sniffer output for the control juice showed a monotonous decline, while the output for the experimental juice exhibited a sharp incline after day four. This sensor output correlated well with the total volatiles.
Growth of Red Maple Taxa in Tennessee
Authors: Witte W.T. , Sauve R.J. , Flanagan P.C.
Published: February 2019

Commercially available Acer rubrum and A. freemanii taxa were established as 10 single-plant replications in a cultivar trial at the TSU–NCRS in 1992 and Spring 1993. Plants were fertilized regularly and drip-irrigated as needed beginning Summer 1993. Growth data were recorded each fall and height and caliper increment calculated for the 1994 season. Ten cultivars were in the group with most height growth: `Armstrong', `Autumn Blaze', `Schlesingeri', `Olson', `Morgan', `Scarlet Red', `Embers', `Indian Summer', `Scarsen', and `October Glory'. These all differed significantly from a group of 11 slow-growing cultivars. With some exceptions, cultivars with the most height growth tended to have the most caliper growth, while those with the least height growth tended to have the least caliper growth. Data will also be presented on insect and disease ratings.
Powdery Mildew Observations and Growth
Authors: Windham M.T. , Witte W.T. , Sauve R.J. , Flanagan P.C.
Published: February 2019

Eighty-one oak taxa were established at the Nursery Crops Research Station in McMinnville, Tenn., in Fall 1993 and Spring 1994. Drip irrigation was applied as needed beginning 18 May 1994 and plants were fertilized regularly. Powdery mildew began to appear in July on some taxa. Each plant was rated on a scale where 0 = healthy plant and 5 = totally mildewed. Height and caliper were recorded in Fall 1994 and the 1994 growth increment calculated. Quercus robur fastigiata was most severely affected by powdery mildew (4.1), followed by a group of six taxa, including douglasii, oglethorpensis, macrocarpa, virginiana, prinus, and aliena (2.3–1.4). There were slight amounts of mildew on 26 taxa and 48 taxa were mildew-free. Growth increment in height and caliper will also be presented.
Powdery Mildew Observations and Growth of Lilac in Tennessee
Authors: Windham M.T. , Witte W.T. , Sauve R.J. , Flanagan P.C.
Published: February 2019

Sixty cultivars of lilac obtained from two commercial nurseries were planted 18 May 1994 and immediately placed under drip irrigation and fertilized regularly. Powdery mildew appeared in July. Each plant was rated in July, August, and September for powdery mildew on a scale of 1 (healthy) to 5 (totally mildewed). There were 22 cultivars in the most resistant group (0–1.8) in July, 13 in August (0–1.0), and 11 in September (0–1.0). Mildew-free were: `Miss Kim', `Royalty', `Palibin', `Summer Snow', `White Summers', `Minuet', `Ivory Silk', `Anna Amhof', `Donald Wyman', but these were not significantly different from `James MacFarlane' and `Superba' (<10%of plant mildewed). Data on growth will also be presented.
RAPD Analysis of Acer
Authors: Gawel Nick J. , Mellinger Rory , Stout Eric , Sauve R.
Published: February 2019

DNA from 27 Acer species was used for RAPD analysis. A relatively high number of phylogenically informative polymorphisms were detected, as would be expected in intraspecific comparisons. Principle coordinates analysis was used to discern groupings among the species and a RAPD-based phylogeny was constructed. As expected when making comparisons among species, very high levels of polymorphism were found. Cultivars that grouped together in the principle components analysis also grouped together in the phylogenic analysis. Parts of the phylogenic analysis do not agree with morphology-based phylogenies. This may be due to poor correlation between morphological and DNA markers, or perhaps RAPDs may be too discriminatory to be used for interspecies comparisons. The extremely high level of between-species variation coupled with the low level of within-species variation, indicates the potential of DNA-based identification and discrimination of Acer species is high.
Using Chloroplast Fluorescence for Prediction of Scald Development in `Red Delicious' Apple Fruit
Authors: Beaudry Randolph M. , Song Jun , Deng Weimin
Published: February 2019

Apple scald (peel browning) is hypothesized to involve a chilling disorder. Numerous studies have linked chloroplast fluorescence changes with chilling injury before symptom development. Therefore, chloroplast fluorescence was used for the prediction of scald in apples. `Red Delicious' apple fruit were harvested at three maturities and stored at 1 to 2C. They were removed from storage weekly and placed at ambient temperature (22C). Chloroplast fluorescence was measured at 0, 3, and 7 days after removal. A significant decline in quantum yield response (Fv/Fm), which indicates a reduction of chloroplast function, was recorded after 30 days in first-harvest fruit and 40 to 50 days in the second- and third-harvest fruit. The decline in Fv/Fm preceded scald development by ≈30 days in first-harvest fruit and 20 to 30 days in second- and third-harvest fruit. The data suggest that fluorescence changes and scald development may be related physiologically. Fruit firmness and other fruit ripening phenomena were also measured and their relationship to the fluorescence and scald development were investigated. The results indicated that the chloroplast fluorescence may be used as a predictive tool for scald development in stored apple fruit.
Electronic Sensing of Apple Ripeness Based on Volatile Gas Emissions
Authors: Hetzroni Amots , Charles Denys J. , Janick Jules , Simon James E.
Published: February 2019

A prototype of a nondestructive electronic sensory system (electronic sniffer) that responds to volatile gases emitted by fruit during ripening was developed. The electronic sniffer is based upon four semiconductor gas sensors designed to react with a range of reductive gases, including aromatic volatiles. In 1994, we examined the potential of using the electronic sniffer as a tool to nondestructively determine ripeness in `Golden Delicious' and `Goldrush' apples. Fruit were harvested weekly from 19 Sept. to 17 Oct. (`Golden Delicious') and 27 Sept. to 18 Nov. (`Goldrush'). Each week, apples of each cultivar were evaluated individually for skin color, weight size, and headspace volatiles. Each fruit was then evaluated by the electronic sniffer, and headspace ethylene was sampled from air within the testing box. Individual fruits were then evaluated for total soluble solids, firmness, pH, total acidity, and starch index value. The electronic sniffer was able to distinguish and accurately classify the apples into three ripeness stages (immature, ripe, and over-ripe). Improved results were obtained when multiple gas sensors were used rather than a single gas sensor.
Apple Storability as Influenced by Tufted Apple Bud Moth Injury, Orchard Fungicide Programs, and Horticultural Factors
Authors: Barden C.L. , Greene G.M. , Hull L.A. , Hickey K.D.
Published: February 2019

As public pressure increases to reduce the use of agricultural chemicals, the effects of lower chemical dosages in the orchard on fruit storability must be determined. Based on both artificial and natural damage, minor tufted apple bud moth (TABM) injury (<10 mm aggregate diameter) did not cause significant loss during controlled-atmosphere (CA) storage. However, damage in excess of 10 mm often caused significant weight loss and decay. Damage occurring closer to harvest caused more loss of quality than earlier damage (i.e., during July and early August). Forty percent of apples damaged 1 week before harvest decayed during storage. Several orchard fungicide spray programs were studied, and in 1993–94, all of the tested programs adequately controlled both fruit blotches and rots, and few storage rots developed. These diseases were light in 1993 due to low rainfall during the summer months. Development of the summer diseases were somewhat higher in 1994, but similar fungicide programs provided adequate control of the complex at harvest. Apples inoculated with P. expansum (punctured with a nail) decayed less when stored in 3% CO2 than in 0% CO2 (at both 1% or 2.4% O2). Decay of `Golden Delicious' caused by P. expansum inoculation increased with later harvest (twice as much decay in fruit harvested 14 Oct. than in fruit harvested 23 Sept.–7 Oct.).
Sweet Corn Cultivar Response to Postemergence Application of ALS/AHAS Inhibitors
Authors: Siegelin Steven D. , Daniels Darrel D. , Ross Merrill A. , Weller Stephen C.
Published: February 2019

This study was conducted in 1993 and 1994 to determine if nicosulfuron or primisulfuron had any adverse effects on ear or whole-plant development. Factors considered were cultivar, herbicide, rate, and timing of application. Four sweet corn cultivars: `More' (su), `Calico Belle' (se), and `Frontier' and `Challenger' (sh2) were evaluated for foliar injury, plant vigor, plant height (1994 only), ear injury, and yield. Nicosulfuron and primisulfuron were applied at two rates: the labeled rate (x) of 35 g a.i./ha and 40 g a.i./ha, respectively, and at the 2x rate. Herbicides were applied early postemergence at V2 (corn height 10–15 cm) or late postemergence at V7 (corn height 30–50 cm). Plant foliar injury ratings, ear injury ratings, number of ears, number of injured ears, and yields were collected. Ears with injury were described as pinched. There was a constriction of the cob, caused by a reduction in kernel row number, ranging from two to eight rows lost. Sweet corn cultivars varied in their response to nicosulfuron and primisulfuron. Timing of application had a greater impact on ear injury than did the rate. Applications at the V7 stage caused more severe ear injury than application at the V2 stage. Ear injury was more severe in nicosulfuron treatments than primisulfuron treatments. Height reductions were caused by both compounds at both applications, with primisulfuron causing greater stunting. Primisulfuron caused more severe foliar injury.
Propane Burner Characterization for Thermal Weeding
Authors: Gill J. , Laguë C. , Lehoux N. , Péloquin G. , Coulombe J. , Yelle S.
Published: February 2019

To develop new alternatives to chemical pesticides in agriculture, a research program was elaborated on the use of propane flamers for weed control. One part of this project is the evaluation of different propane burners commercially available. We measured the temperature distribution within the burner flames and the fuel consumption of three different types of burner. Flame characterization allowed for the selection of appropriate burners and settings for specific applications. We also investigated the effect of preemergence thermal weeding on crop establishment for 10 different crops. The use of flaming in preemergence of crops is an effective method for controlling weeds, especially for younger and broadleaf weeds. Depending on the crop, thermal weeding can affect the emergence rate when applied just before seedling emergence.
Preemergent Weed Control in Container-grown Herbaceous Perennials
Authors: Klett James E. , Hillock David
Published: February 2019

Herbicides were applied to container-grown herbaceous perennials and evaluated on the basis of weed control and phytotoxicity. During the 1994 season, seven preemergent herbicides, napropamide (Devrinol) at 4.5 and 9.1 kg·ha–1, metolachlor (Pennant) at 4.5 and 9.1 kg·ha–1, isoxaben (Gallery) at 1.1 and 2.3 kg·ha–1, oxadiazon (Ronstar) at 4.5 and 9.1 kg·ha–1, oxyfluorfen + oryzalin (Rout) at 3.4 and 13.6 kg·ha–1, oryzalin (Surflan) at 2.8 and 4.5 kg·ha–1, and trifluralin (Treflan) at 4.5 and 9.1 kg·ha–1, were tested on Aquilegia caerulea `McKana's Giant', Digitalis purpurea, Gaillardia aristata, Limonium latifolium, and Veronica spicata. Isoxaben (both rates) resulted in visual phytotoxicity symptoms and death to Digitalis. Metolachlor (both rates) resulted in plant death to Veronica. Pennant (both rates), when applied to Limonium, resulted in stunted growth. Aquilegia and Gaillardia were not adversely affected. Most herbicides controlled both dicot and monocot weeds effectively.
Evaluation of Techniques for Screening Verticilium Wilt of Capsicum annuum
Authors: Riley M.K. , Bosland P.W.
Published: February 2019

Two studies were performed to evaluate techniques for screening verticillium wilt of Capsicum annuum L. The first study tested inoculation methods. The original method involved mixing the inoculum with planting medium in a cement mixer for 1 h. Seeds then were planted in the infested medium. In the new technique, inoculum is poured directly into the row, and seeds are placed directly on top of the inoculum. Inoculum levels of 2000 and 1000 mcrosclerotia/g of soil were tested in the new “in-row” method. The disease severity of the “in-row” plants was significantly less than the plants inoculated by the original method. A significant difference remained between resistant and susceptible lines. There was no difference between inoculum levels. The second study compared three commercial planting media to the standard soil used in previous screenings. Disease severity did not differ among media, and all media showed significant differences between resistant and susceptible C. annuum lines.
Combining Ability and Correlations for Fruit Firmness Components in Parthenocarpic × Nonparthenocarpic Pickling Cucumber Hybrids
Authors: Cook Kevin L. , Gabert August C. , Baggett James R.
Published: February 2019

One concern that has restricted the use of parthenocarpic pickling cucumber cultivars in the United States has been firmness of fruit processed by brining. Selection for mesocarp and endocarp firmness, in addition to morphological traits associated with firmness, such as fruit length, length: diameter ratio, seed cavity size, and seed cavity: fruit diameter ratio, may produce parthenocarpic cultivars with improved quality. Combining ability of a set of parthenocarpic and nonparthenocarpic parents for fruit firmness and these related morphological characteristics were investigated using a factorial mating design grown in 1992 and 1994 at Brooks, Ore. General combining ability was greater than specific combining ability for all traits before and after processing. Fruit firmness, mesocarp firmness, endocarp firmness, length, and length: diameter ratio were positively correlated phenotypically and genetically to one another. Seed cavity diameter and seed cavity: fruit diameter ratio were positively correlated phenotypically and genetically, but were negatively correlated to all other traits.
The Inheritance and Association of Rust (Uromyces apendiculatus) Resistance and Foliar Abnormalities in Phaseolus vulgaris L.
Authors: Bokosi J.M. , Coyne D.P. , Steadman J.R. , O'Keefe D. , Reiser J.
Published: February 2019

The inheritance of specific resistance (SR) and foliar abnormalities (FA) were studied in the F2 and F3 progeny of the following crosses; `PC-50' × Chichara 83-10, `PC-50' × `EZ Pick', A-10-2 × GN `Beryl', and A-10-2 × P114. A single dominant gene controlled SR to rust strain US85NP10-1 in `PC-50' × Chichara 83-10. Duplicate recessive genes determined foliar crippling (FC) in `PC-50' × Chichara 83-10 and A-10-2 × P114. The inheritance of hybrid plant abnormality in `PC-50' × `EZ Pick' and A-10-2 × GN `Beryl' differed from previously reported complementary dominant genes or duplicate recessive genes. Foliar variegation (FV) was controlled by duplicate recessive genes in `PC-50' × Chichara 83-10 and by triplicate recessive genes in `PC-50' × `EZ Pick', A-10-2 × GN `Beryl', and A-10-2 × P114. No associations were detected between SR and FC, SR and FV, or FC and FV.
Heat-induced Volatiles in Fresh Broccoli
Authors: Forney Charles F. , Jordan Michael A.
Published: February 2019

Heat can induce physiological changes in plant tissues, including the inhibition of broccoli senescence. Hot water treatments at 52C for 3 or more minutes may induce off-odors in fresh broccoli. The objective of this study was to identify heat-induced volatiles that may indicate physiological injury and/or be responsible for off-odors. Heads of fresh broccoli (Brassica oleracea L. Italica group cv. `Paragon') were immersed in water at 25C for 10 min (control); 45C for 10, 15, or 20 min; or 52C for 1, 2, or 3 min. Following treatment broccoli was held at 20C in the dark. Volatiles in the headspace above treated broccoli were trapped on Tenax-GR 2, 24, and 72 h after treatment and analyzed on a GC-MS. Heat treatments increased the production of ethanol, dimethyl disulfide (DMDS), dimethyl sulfide (DMS), dimethyl trisulfide (DMTS), hexenol, methyl thiocyanate, and several other unidentified compounds. Two hours after treatment, ethanol and hexenol concentrations in the headspace of all heat-treated broccoli were greater than those of the 25C/10 min controls. In the 52C/3 min-treated broccoli, headspace concentrations of ethanol, hexenol, DMDS, and methyl thiocyanate were 600-, 42-, 4-, and 4-fold greater than those of controls. After 72 h at 20C, concentrations of DMDS, DMS, and DMTS in broccoli from all six heat treatments were 10- to 200- fold, 8- to 35-fold, and 1.5- to 23- fold greater than those of controls, respectively. Concentrations of ethanol and methyl thiocyanate did not change relative to the controls during the additional 70 h at 20C. Concentrations of hexenol decreased in heat-treated broccoli during this time. The relationship of these volatiles to physiological changes and off-odor development in treated broccoli will be discussed.
Effect of Methyl Jasmonate on the Quality of Chilled Zucchini Squash
Authors: Wang Chien Yi
Published: February 2019

Methyl jasmonate (MJ) was applied to zucchini squash (Cucurbita pepo L.) fruit be pressure-infiltration (82.7 kPa for 3 min). Control fruit were similarly treated with distilled water. All fruit were then stored at a chilling temperature of 5C. Chilling injury occurred in the control fruit within 4 days of storage. However, the onset of chilling injury was significantly delayed by the MJ treatment. MJ-treated fruit also maintained higher levels of carbohydrates, while malic acid was the major organic acid. These constituents deteriorated slower in the MJ-treated fruit than in the control fruit.
Cuticle Differences during Ripening of Normal and rin Tomato Fruits
Authors: Mendoza-Wilson A. , Siller J. , Bringas E. , Ojeda J. , Báez J. M. , Báez-Sanudo R.
Published: February 2019

Ripening mutant gene rin (ripening inhibitor) in tomato inhibits, or greatly slows down, a wide range of processes related to ripening of the fruit, leading to a markedly extended shelf life. Although the use of films or coatings has been shown to retard ripening, the natural film that covers the fruit and delimits interchange with the environment, the cuticle, has not been well-characterized and related to ripening. The objective of this work was to characterize cuticle changes and establish their relationship with respiratory behavior. Turning tomato fruits with the gene rin, selection S-164 and normal tomato fruits were stored under marketing conditions (20C; 65% to 70% RH) to determine cuticular and physiological changes. Parameters evaluated were: cuticular weight changes (CW), permeability, soluble cuticular lipids (SCL), and epicuticular waxes (EW). In addition CO2 production was monitored every other day. Normal fruit increased in CW from 1.17 to 1.30 mg·/cm–2 and its EW from 11.49 to 24.49 μg·cm–2. On the other hand, rin tomatoes declined in CW and EW during storage. Both kind of fruits decreased their SCL content. Normal tomatoes exhibited the characteristic climacteric peak and showed an increase of cuticle permeability, while in rin tomatoes, these changes were not expressed.