bluuebunny/crossref_metadata_2025 huggingface dataset:
Teaching Pruning through Television
Authors: Polomski R.F. , Bradshaw D.W. , Head R.H. , Reighard G.L.
Published: February 2019

Two interactive pruning televideoconferences were produced, each comprised of videotaped segments and in-studio pruning demonstrations. In the first televised conference, viewers received step-by-step instructions for pruning four small and tree fruits. Twelve woody ornamentals were pruned in the second conference. The “how-to-prune” segments were performed by Extension personnel and videotaped by University Electronic and Photographic Services. Each of the 2-hour conferences was broadcast live from a classroom television studio with a total of 30 in-studio participants and 178 county extension agents, Master Gardeners, and residents at downlink sites statewide. A toll-free number was available throughout the conference to encourage two-way communication. These televideoconferences culminated in the creation of a library of “how to prune” videotapes, which are available to county agents, Master Gardeners, or residents. Also, several of these segments were aired on C.U.E. Magazine, a monthly, half-hour Extension-sponsored cable television program, and on Making It Grow!, a bimonthly, hour-long Clemson Extension program that is broadcast on SC-Educational Television.
Real-Time Measurement of NO3− and NH4+ Leaching from Plant Nursery Pots
Authors: Wang Tiangen , O'Hair Stephen K.
Published: February 2019

Concerns relating to pollution from nitrogen fertilizers leaching into ground water are increasing. This is especially important in southern Florida because the pollution threatens fragile ecosystems in Biscayne Bay, and the two National Parks that abut agricultural areas. The current research is focused on the development of an automatic system which can monitor and leaching from plant nursery pots. and electrodes and a load cell were used for real-time measurements of , , and leachate volume. The leachate was directed to pass the sensing areas of , reference, pH, and electrodes. It was collected and weighed in a container placed on a load cell. The analog signals from the electrodes and load cell were digitized through data acquisition technology using a 16-bit A/D converter and a self-developed software program. With this system the volume of the leachate and concentrations of and in the leachate were determined in situ. Based on this design, the dynamics of and leaching from pots can be observed. This system can be used to 1) determine soil (or media) holding capacity of and , 2) evaluate the effects of nitrogen fertilizer formulations on water quality, 3) develop best management practices of nitrogen application in containerized plant production, and 4) determine the soil-holding capacity to optimize the use of water. The advantages of the developed system are 1) low labor cost for sample collection and analysis and 2) high measurement resolution resulting from a minimization errors that occur during sampling and other manual operations.
Water Relations of Acer rubrum in Response to Summer Digging
Authors: Knight P.R. , Harris J.R. , Fanelli J.K. , Kelting M.P.
Published: February 2019

Two experiments were conducted on Acer rubrum L. to determine the influence of root severance on sap flow, stomatal conductance, leaf water potential (ψ), and stem xylem embolism. Experiment 1 utilized 3-year-old trees, and experiment 2 utilized 2-year-old trees. Sixteenmm sap flow gauges were installed on both groups. Trees for experiment 1 were harvested on 31 May 1996 with a root ball diameter of 30.5 cm. Sap flow was reduced within one day after plants were harvested and was still lower 1 week after harvest. On 7 June 1996, harvested trees had lower stomatal conductance measurements, compared to not-harvested trees, but ψ were similar. A second experiment was initiated on 20 Aug. 1996, using the same protocol as in experiment 1. Sap flow was reduced within 2 h after harvest for harvested trees compared to not-harvested trees. Leaf stomatal conductances were reduced within 4 h of harvest. Leaf water potentials were not influenced on the day that the trees were harvested. Embolism levels were increased by harvest within 24 h. These results indicate that transplant stress begins shortly after harvest and not at the actual time of transplant.
Three New Rabbiteye Blueberries From North Carolina
Authors: Ballington James R. , Rooks Susan D.
Published: February 2019

Three rabbiteye blueberry selections, NC 1550, NC 1877, and NC 2305, will be released by the North Carolina Agricultural Research Service in Spring 1997. All three selections are self-fruitful, with fruit as large or larger than Tifblue, with good picking scars, aromatic flavor, and resistance to fruit cracking. NC 1877 is early-blooming and ripens a few days later than Premier, with similar color, firmness, and quality. Plants of NC 1877 are semi-upright and of only moderate vigor. Both NC 1877 and NC 1550 are resistant to the sharpnosed leafhopper which transmits blueberry stunt. NC 1550 blooms with or slightly later than Tifblue and is outstanding for consistent productivity, particularly on spring frost—prone sites. It ripens in early midseason to midseason, usually a few days ahead of Tifblue. Stemming was a problem in one year on overcropped plants. NC 1550 and NC 2305 have average to above color, and fruit firmness equal to Tifblue. NC 2305 blooms and ripens with Tifblue in most years. Fruit quality is at least equal to Premier and it fruits primarily on the tips of the branches. The names of these selections are Ira' (NC 1550), 'Montgomery' (NC 1877), and 'Yadkin' (NC 2305).
Mulch Color Influence on Annual Hill Plasticulture Strawberries
Authors: Himelrick David G.
Published: February 2019

The effect of seven types of plastic mulches on total, early, and late season yield was evaluated for three years in the annual hill strawberry production system. Black plastic mulches differed only from the significantly reduced yields found on unmulched bare ground treatments. Although not significantly different in any year, the top performing mulch treatments varied with production year and cultivar. In the wet and warm harvest season of 1991, the highest yielding treatments were IRT-76, clear, and ALOR-brown. In the dry and cool 1992 season, the top performers were white on black, black, and ALOR-brown. For the cool and moderately wet 1993 season, the best performance was recorded on black, white on black, and clear. Average soil temperatures from warmest to coolest were found with black, black on white, clear, IRT-76, ALOR-brown, red, silver, white on black, and bare soil treatments.
Possible Role of Lipoxygenase in Plant Response to Drought Stress
Authors: Ebel Robert C.
Published: February 2019

Apple leaves were shown to increase 6 volatile compounds in response to drought stress severe enough to promote senescence. Apple trees were allowed to dry to -2.0 MPa and -2.7 MPa, levels that were previously shown to reduce fruit growth by 50% and 70%, respectively. The 6 volatile compounds measured included hexanal, (E)-2-hexenal, 1-hexanol, (E)-2-hexen-l-ol, hexyl acetate, and (Z)-3-hexenyl acetate. Hexanal, (E)-2-hexenal, and 1-hexanol have been previously shown to be byproducts of lipoxygenase (LOX) activity. There is considerable information in the literature implicating LOX as a key enzyme involved in senescence, whether induced by pathogenic infection, insect feeding, or in ripening climacteric fruit and vegetables. It is reasonable to propose that LOX is also involved in promotion of senescence induced by drought stress.
Strawberry Breeding for the Southern United States
Authors: Galletta Gene J.
Published: February 2019

This review briefly summarizes the status of the Southern strawberry industries during the 20th century. Objectives, contributions, and personnel of the Southern state and federal improvement programs are presented. The future of the southern strawberry industries and their reduced number of breeding programs are predicted, with emphasis on the objectives which may have to be altered to accommodate new and continuing problems.
Pierce's Disease of Texas Grapevines
Authors: McEachern G.R. , Kamas Jim , Cook Doug , Johnson Jerral
Published: February 2019

Since 1977, it was believed the grape strain of Xylella fastidiosa, Pierce's Disease (PD), was limited to sites receiving less than 800 hours of winter chilling below 45 °F. Warm winters since 1992–93 resulted in numerous PD-positive vineyards in central Texas which were previously nonaffected. Vine mortality ranges from minimal to over 80% dead vines. A Davis Mountains site receiving over 1,000 hours was also severely infected in 1996. The last severe winter in Texas was 1989–90; therefore, warm winters could be contributing. This climatic change could have affected vines, vectors, bacteria, and/or hosts. Recent work based on a study of 20 PD samples, 11 from Texas and 9 from other states, including California and Florida, indicates that the samples of PD grape strain of Xylella fastidiosa are clonally related. ELISA tests failed to identify PD from 1994–96; therefore, a sensitive REP-PCR test is needed before vine, bacteria, vector, and host management strategies can be developed.
Postharvest Behavior of Watermelon Fruit Blotch
Authors: Rushing James W. , Cook Wilton P. , Keinath Anthony P.
Published: February 2019

Transmission of watermelon fruit blotch was not observed during the first week of postharvest storage at either 11 °C or 20 °C when the diseased surface of an affected watermelon was placed in direct contact with the surface of a healthy fruit. Abrasion of either the diseased fruit, the healthy fruit, or both fruit did not facilitate transmission of the disease compared to unabraded controls. After 3 weeks' storage, disease transmission was significantly greater at 20 °C than at 11 °C, illustrating the importance of appropriate temperature management during postharvest handling. Harvesting appears to arrest the development of watermelon fruit blotch if the disease symptoms cover less than approximately 5% of the fruit surface at harvest.
The Effect of Colored Plastic Mulches on Whitefly Populations in Watermelon Production
Authors: Brandenberger L.P. , Wiedenfeld R.P.
Published: February 2019

The squash leaf curl virus (SLCV), transmitted by the sweet potato whitefly (Bemesia tabaci biotype B), is widespread on fall-planted watermelon in the Rio Grande Valley and Coastal Bend areas of south Texas. The objective of the study was to evaluate colored mulches for their effects on whitefly populations, virus incidence, and watermelon yield. Eleven polyethylene films were included as treatments in both a spring and fall study and were replicated five times in a randomized block design. Plastic mulches caused substantial improvement in melon yields (40%) in the spring crop, similar to responses obtained in other studies on cantaloupes. Fall yield increases due to the use of mulches did not occur. Whitefly populations were much lower in 1996 than they have been in previous years, therefore this was not an adequate test of its effects on whitefly behavior. Even so, there were indications in the fall crop that the use of plastic mulch tended to result in lower whitefly numbers. No evidence was found of any difference between the various mulch materials regarding whitefly counts.
Broadcast vs. Band Applications of Fertilizer for Vegetable Crops
Authors: Parish Richard L. , Bracy Regina P. , Morris Hershel F.
Published: February 2019

A study was conducted to evaluate the effect of banding or broadcasting fertilizer on yield and quality of turnip (Brassica rapa L. Rapifera group), sweetcorn (Zea mays var. rugosa Bonaf), and cabbage (Brassica oleracea L. Capitata group). Preplant fertilizer was applied broadcast prior to bedding, broadcast after bedding, or banded after bedding. Sidedress applications were broadcast or banded on the beds. Strong visual differences were noticed early in the season in the spring turnip crop with the growth in the broadcast-then-bed treatment appearing superior. The yield at first harvest and total yield were lower for turnip growth with the bed-and-broadcast treatments. No differences in yield of cabbage and sweetcorn resulted from the treatments. Few differences in turnip stem to leaf ratio were noted due to fertilizer treatment. Few differences in yield due to sidedress method were noted with any of the crops. Since broadcasting can be done with a faster, wider applicator, growers could reduce costs by broadcasting fertilizer and obtain yields that are at least equivalent to the yields from banding.
Evaluation of Presswheels and Seed Coverers for Direct Seeding of Brassica
Authors: Bracy Regina P. , Parish Richard L.
Published: February 2019

Improved stand establishment of direct-seeded crops has usually involved seed treatment and/or seed covers. Planters have been evaluated for seed/plant spacing uniformity, singulation, furrow openers, and presswheel design; however, effects of presswheels and seed coverers on plant establishment have not been widely investigated. Five experiments were conducted in a fine sandy loam soil to determine effect of presswheels and seed coverers on emergence of direct-seeded cabbage and mustard. Seed were planted with Stanhay 870 seeder equipped with one of four presswheels and seed coverers. Presswheels included smooth, mesh, concave split, and flat split types. Seed coverers included standard drag, light drag, paired knives, and no coverer. Soil moisture at planting ranged from 8% to 19% in the top 5 cm of bed. Differences in plant counts taken 2 weeks after planting were minimal with any presswheel or seed coverer. Visual observation indicated the seed furrow was more completely closed with the knife coverer in high soil moisture conditions. All tests received at least 14 mm of precipitation within 6 days from planting, which may account for lack of differences in plant emergence.
Field Performance of Lettuce Grown in Alabama
Authors: Simonne Eric H. , Simonne Amarat H. , Wells Larry W. , Ruf Marvin E. , Owen John T.
Published: February 2019

While lettuce is one of the most widely consumed vegetables in the United States, production is mainly concentrated in the western states. This research investigated the feasibility of lettuce production in the Southeast (SE), where downy mildew, tip burn, bitterness, bolting, and postharvest handling are potential production problems. Lettuce varieties were evaluated on plastic mulch and drip irrigation under several growing conditions. Cultivar and location significantly (P < 0.01) affected yield and transplant survival rate. Following these tests, 'Salinas 88 Supreme', 'Legacy', 'Bullseye', 'Epic' (crisphead); 'Nancy', 'Nevada', 'Ostinata' (butterhead); 'Parris Islands', 'Augustus' (Romaine); and 'Red Salad Bowl', 'Red Prize', and 'Slobolt' (loose leaf) are considered best-performing lettuce varieties for Alabama. These results, along with bitterness evaluation, support the potential for lettuce production in the SE.
Sensory Evaluation of Bitterness in Lettuce Varieties Grown in the Southeastern United States
Authors: Simonne Amarat H. , Simonne Eric H. , Eitenmiller Ronald R. , Owen John , Wells Larry
Published: February 2019

The main limiting factor to lettuce production in the Southeast is bitterness. Bitterness in lettuce is associated with sesquiterpene lactones, a bitter principles of the latex of wild lettuce species Lactuca virosa or L. sativa. These wild species are used as parents in the development of virus-resistant cultivars. This study evaluated bitterness of 18 commercial cultivars of lettuce grown following recommended production practices at two locations. Lettuce was hand harvested, refrigerated, washed, and cut into bite-size pieces. Samples were served one by one to a group of 15 panelists, trained with caffeine solutions of increasing bitterness scores (BS; 0% = 0, 0.05% = 2, 0.08% = 5, 0.15% = 10, and 0.20% = 15). A BS of less than seven was acceptable. BS was significantly (P < 0.02) different among varieties. Varieties with lowest BS were `Epic', `Salinas 88 Supreme', `Nevada', `Red Prize', and `Legacy'. For these varieties, mean, most frequent, and highest BS were less than seven. This study suggests that it is possible to grow nonbitter lettuce in the Southeast.
Influence of Various Polyethylene Mulch Colors on Growth and Development of `Vates' Collards
Authors: Kemble J.M , Brown J. , Simonne E.
Published: February 2019

The effect of various mulch colors (black, yellow, red, blue, white, and aluminum) on growth and development of `Vates' collards was evaluated in Fall 1996 at the E.V. Smith Research Center in Shorter, Ala. Black polyethylene mulch was installed onto raised, fumigated beds, then sprayed with a 1: 2 (v/v) mixture of exterior oil-based enamel paint to paint thinner with one of the five mulch colors listed. Five-week-old plants were transplanted into beds. Beginning two weeks after transplanting and continuing every other week thereafter, heads were harvested to determine head fresh weight and dry weight. Hourly soil temperatures at 10 cm soil depth were recorded and growing degree days (GDDs) with a base temperature of 4.4 °C were calculated. At two weeks after transplanting, average head fresh and dry weight were highest for the aluminum-colored treatment with head fresh (24.7 and 12.3 g, respectively) and dry weights (2.7 and 1.3 g, respectively) twice that of the yellow treatment (P ≤ 0.05). By four weeks after transplanting and up through the final harvest, marketable yield and average head fresh weights did not differ among the treatments (17,900 kg/ha, 1.4 kg per head, respectively). The red and black mulch treatments accumulated more GDDs than the other treatments, but total marketable yields did not differ among any treatments.
Effects of Different Cover Crops on Sweet Corn and Bell Pepper Production
Authors: Ranwala N.K. Damayanthi , Brock Kathy , Ray Chris L. , Greene Katie , Decoteau Dennis R.
Published: February 2019

Rye and crimson clover as winter cover crops and red clover as a companion crop were evaluated in sweet corn and bell pepper production systems in South Carolina. Winter cover crops were planted in fall and incorporated into the soil 3 weeks prior to planting vegetable crops. Red clover was overseeded with the vegetable crops. There were no significant differences among treatments for corn yield. Marketable number and weight of bell peppers were significantly higher in both winter cover crops compared to red clover and fallow (control) treatments. Number of cull peppers (smaller peppers than USDA grades) were lower in both cover crops compared to other treatments. Lack of response in red clover compared to the fallow treatment may be due to the lower emergence of red clover when used as a companion crop with bell pepper. Marketable bell pepper yield was higher in the late harvest compared to the early harvest in all the treatments.
Bell Pepper and Lettuce Response to Garlic Sprays
Authors: Simonne Eric H. , Owen John T. , Kemble Joseph M.
Published: February 2019

The efficacy of garlic spray (GS; Garlic Barrier™) as an alternative to conventional chemical control of disease and insect pests was evaluated on bell pepper and lettuce. Treatments consisted of a recommended chemical spray as needed (Treat. 1), GS applied once (Treat. 2) or twice (Treat. 3) a week, and water spray applied twice a week (Treat. 4). Because of no pest pressure during the test, no chemical sprays were used in Treat. 1. Differences among bell pepper yields were not significant (P > 0.50). For lettuce, Treat. 2 resulted in significantly (P = 0.02) higher head yield. Differences among treatments were not visually detectable in the field. These results suggested that GB applied at the manufacturer's rate (Treat. 2) did not adversely affect bell pepper and lettuce growth and yield. Garlic smell was not detectable on either vegetables, even after Treat. 3. Due to a low pest pressure, this study failed to identify beneficial effects of the GS. Without more scientific reports, relying only on GS to control pests of bell pepper and lettuce may involve uncontrolled risks.
Al, Mn, And Ca Fertilization on Two Rabbiteye Blueberry Cultivars
Authors: Spiers J.M. , Braswell J.H.
Published: February 2019

The effects of varying Al, Mn, and Ca fertilization levels on `Tifblue' and `Brightwell' rabbiteye blueberry (Vaccinium ashei Reade) plant growth, chlorosis symptoms, and leaf elemental content were studied in a sand culture experiment. Increased Al fertilization linearly decreased Ca, Mg, and Mn leaf concentrations and plant vigor. Calcium fertilization did not affect plant growth or leaf concentration of the two cultivars. Increased Mn fertilization increased Al and Mn leaf concentrations and resulted in more chlorosis symptoms. Plants fertilized with the highest rates of Al and Mn had the least amount of growth.
Effect of Soil Applications of Iron, Copper, Zinc, and Manganese on the Growth of Young Papaya Plants
Authors: Santos Bielinski M. , Morales-Payan Jose P.
Published: February 2019

The response of young `Cartagena Ombligua' papaya (Carica papaya) plants to soil-applied copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) was determined. Nursery experiments were conducted in the Dominican Republic, where Cu (0, 0.023, 0.046, 0.069, and 0.092 g), Mn (0, 0.27, 0.54, 0.81, and 1.08 g), Fe (0, 0.49, 0.98, 1.47, and 1.96 g) and Zn (0, 0.2, 0.4, 0.6, and 0.8 g per plant) were individually applied 20 days after transplanting. There were significant responses to the four elements. Maximum growth was obtained with 0.092 g Cu, 0.4 g Zn, 0.54 g Mn, or 0.98 g Fe per plant.
Initial Observations on Cassava (Manihotesculenta Crantz) Establishment and Adaptability in the Rio Grand Valley
Authors: Makus D. J.
Published: February 2019

Four cassava (Manihot esculenta Crantz) accessions were received from the USDA, ARS Plant Introduction Station in Mayaguez, PR on 16 Jan. 1996. The next day the 15- to 20-cm-long cuttings were propagated individually in 1-gal. pots containing Metro Mix No. 4 for 10 weeks before field setting into a transition Hidalgo-McAllen fine sandy loam soil on a USDA, APHIS site near McCook, Texas. Three plant establishment methods, control (no soil amendment), addition of 15 Mt bagasse/ha, or 50 kg cross-linked polyacrylamide/ha into the planting trench were evaluated. The 2 × 1.2 m spacings on 15-cm-high beds provided 4036 plants/ha. Plants received a total of 35.8 cm of water between field planting and harvest (230 days). Mid- and late-season soil moisture (kg/m3) at 38 cm depth only was lowest in soil containing bagasse. Establishment method had little or no effect on plant size, leaf nutrients, leaf pigment concentrations, root dry matter, or root yield. Accessions differed in many of these attributes except root yield, the means of which ranged from 5 to 9 Mt/ha. Only roots survived an air temperature of -5.4 °C on 19 Dec.
Portable Through-flow Cuvette System for Measuring Whole-canopy Gas Exchange of Apple Trees in the Field
Authors: Wünsche Jens N. , Palmer John W.
Published: February 2019

A monitoring and control system for sequentially measuring whole-tree-canopy gas exchange of four apple (Malus domestica Borkh.) trees in the field is described. A portable, highly transparent, open-top whole-canopy cuvette was developed for complete enclosure of the above-ground portion of the tree. The flux of whole-canopy CO2 and H2 0 vapor was estimated from differential CO2 concentration and H2O-vapor partial pressure between ambient/reference air entering the cuvette and analysis air leaving the cuvette, as measured by infrared gas analysis. The bulk air-flow rate through the chamber was measured with a Pitot static tube inserted into the air-supply duct and connected to a differential pressure transducer. Performance of the whole-canopy cuvette system was tested for its suitability for gas-exchange measurements under field conditions. The air flow through the whole-canopy cuvette was 22000 L·min-1 (≈5.5 air exchanges/min) during the day, providing adequate air mixing within the cuvette, and 4000 L·min-1 (≈1 air exchange/min) during the night. Daily average leaf temperatures within the cuvette were 2-3 °C higher than to those on trees outside the cuvette. Photosynthetic photon flux transmitted through the chamber walls was at least 92 % of the incident ambient radiation. Moreover, the whole-canopy cuvette was evaluated without tree enclosure to determine the degree of “noise” in differential CO2 concentration and H2O-vapor partial pressure and was found to be acceptable with ΔCO2 ± 0.3 (μmol·mol-1 and ΔH2O ± 5 Pa. Whole-canopy carbon gas exchange and transpiration of four cropping `Braeburn'/M.26 apple trees followed closely incident radiation over the course of a day.
Buffalograss Establishment with Preemergence Herbicides
Authors: Fry Jack D. , Gaussoin Roch E. , Beran Dan D. , Masters Robert A.
Published: February 2019

Field studies were conducted at two sites in Nebraska (NE1 and NE2) and one site in Kansas (KS) in 1994 to determine the influence of selected preemergence herbicides on establishment of seeded `Sharp's Improved' buffalograss [Buchloe dactyloides (Nutt.) Engelm.]. Herbicides were applied within 2 days after seeding. Application of imazethapyr at 0.07 kg·ha-1 usually resulted in buffalograss seedling density, vigor, and foliar cover that were superior to buffalograss stands where other herbicides were applied. Buffalograss response to AC 263,222 at 0.07 kg·ha-1 was variable and appeared to be influenced by level of weed interference. Seedling density and vigor of buffalograss on areas treated with AC 263,222 were the same or less than on nontreated areas at KS and NE2, where weed infestations were low and moderate [5% and 45% weed foliar cover 12 weeks after treatment (WAT) on nontreated areas]. In contrast, buffalograss establishment was similar in AC 263,222- and imazethapyr-treated plots at NE1 where the weed infestation was high (>70% weed foliar cover 12 WAT on nontreated areas). At 12 WAT, weed foliar cover was <25 % at NE1 and <1 % at NE2 where imazethapyr and AC 263,222 were applied. Of all herbicides evaluated, imazethapyr at 0.07 kg·ha-1 was superior for suppressing annual grass and broadleaf weeds with no observable deleterious effects on buffalograss establishment from seed. Chemical names used: ±2-[4,5-dihydro-4-methyl-4-(l-methylethyl)-5-oxo-lH-imidazol-2-yl]-5-methyl-pyridine carboxylic acid (AC 263,222); 2-[4,5-dihydro-4-methyl-4-(l-methylethyl)-5-oxo-lH-imidazol-2-yl]-5-ethyl-3-pyridinecarboxylic acid (imazethapyr); 6-chloro-N,N′-diethyl-l,3,5-triazine-2,4-diamine (simazine).
Postharvest Heat Conditioning Effects on Early Ripening `Gialla' Cactus Pear Fruit
Authors: Schirra M. , Agabbio M. , D'Aquino S. , McCollum T.G.
Published: February 2019

The influence of postharvest heat conditioning at 38 °C for 24, 48, or 72 hours on ripe `Gialla' cactus pear [Opuntia ficus-indica (L.) Miller] fruit produced by the spring flush was investigated during 21 days of storage at 6 °C and 90%-95% relative humidity (RH) followed by 7 days at 20 °C and 70%-75% RH (simulated marketing). Conditioning for 24 to 72 h reduced by 50% the severity of chilling injury (CI) on cactus pears following exposure to cold storage. Treatment for 24 to 72 h was also effective in reducing decay, with conditioning for 24 h being the most effective. Overall visual quality was better in heat-conditioned compared with control fruit. Mass loss was significantly reduced by all heat conditioning treatments. Respiration rate was not affected by heat treatment. Ethylene evolution was lower in fruit heat-conditioned for 48 or 72 h than for 0 h. Conditioning for 72 h resulted in the highest fruit ethanol levels. The influence of conditioning on juice pH, titratable acidity, soluble solids concentration and ascorbic acid was negligible. Prestorage heat treatment provides some measure of CI and decay control without detrimental effects to visual quality of early ripening cactus pear fruit and may offer an alternative to fungicide treatments.
Pretreatments at 38 °C of `Hass' Avocado Confer Thermotolerance to 50 °C Hot Water Treatments
Authors: Woolf Allan B. , Lay-Yee Michael
Published: February 2019

`Hass' avocados [Persea americana Mill.] were pretreated in water (38 °C for up to 120 min) immediately before 50 °C hot water treatments of up to 10 min. Fruit were stored for 1 week at 6 °C and ripened at 20 °C. External browning was evaluated immediately upon removal from cold storage, and fruit quality evaluated when fruit were ripe. Pretreatments at 38 °C tended to reduce the levels of external browning, skin hardening, and internal disorders, such as tissue breakdown and body rots, that were associated, and increased, with longer hot water treatments. A pretreatment of 60 min was the most effective for eliminating external browning, and reducing hardening of the skin when fruit were ripe following hot water treatment. Examination of heat shock protein (hsp) gene expression in avocado skin tissue, showed that levels of hspl7 and hsp70 homologous mRNA increased with increasing pretreatment duration. The results demonstrate that 38 °C pretreatments increase the tolerance of avocado fruit to subsequent hot water treatments.
Resistance to Race T2 of the Bacterial Spot Pathogen in Tomato
Authors: Scott J.W. , Miller S.A. , Stall R.E. , Jones J.B. , Somodi G.C. , Barbosa V. , Francis D.L. , Sahin F.
Published: February 2019

Thirty-two tomato (Lycopersicon esculentum Mill.) or L. pimpinellifolium (L.) Mill. accessions were inoculated with race T2 of Xanthomonas campestris pv. vesicatoria (Xcv) in a field experiment at Wooster, Ohio, in 1995. Plants from accessions which segregated for race T2 resistance in greenhouse tests were selected and these are designated by hyphenated extensions below. The eight most resistant accessions from 1995 and PI 262173 were retested in 1996. Lycopersicon esculentum accession PI 114490-1-1 had virtually no Xcv symptoms either year. Lycopersicon pimpinellifolium accessions LA 442-1-Bk and PI 128216-T2 expressed a high level of resistance in 1995, but only partial resistance in 1996. Accessions with partial resistance for both seasons were PI 79532-S1, PI 155372-S1, PI 126428, PI 271385, PI 195002, PI 262173, Hawaii 7998, and Hawaii 7983. PI 79532-S1 is a L. pimpinellifolium accession and the remaining seven are L. esculentum. Twenty accessions tested in 1995 for T2 plus 10 other accessions were also tested for race T1 resistance in Presidente Prudente, Sao Paulo, Brazil, in 1993. Hawaii 7983, PI 155372-S1, PI 114490, PI 114490-S1, and PI 262173 had greater resistance to T1 than the susceptible control, `Solar Set'. Comparisons with earlier experiments, in which accessions were inoculated with race T1 or T3, indicated that the most consistent source of resistance to all three races was PI 114490 or selections derived from it.
Inheritance of Anthocyanin Production and Malate Dehydrogenase Isozymes in Agastache rugosa (Fisher & Meyer) Kuntze
Authors: Fuentes-Granados Roger G. , Widrlechner Mark P.
Published: February 2019

This study was conducted to determine the inheritance of anthocyanin production and of malate dehydrogenase banding patterns in Agastache rugosa. Results of the study support the hypothesis that anthocyanin production is controlled by a single dominant gene, designated as A, for anthocyanin production. The Mdh-3 banding patterns are controlled by two alleles, each of which associated with a two-banded phenotype. A monomeric quaternary structure of MDH, which is rather atypical among plant species, can be inferred from the results. No linkage was found between the loci governing anthocyanin production and Mdh-3 banding patterns. This is the first report of heritable variability in A. rugosa.
Shoot Length Affects Susceptibility to Mummy Berry Blight within Highbush Blueberry Cultivars
Authors: Ehlenfeldt M.K. , Stretch A.W. , Lehman J.S.
Published: February 2019

Shoot growth of six blight-resistant highbush blueberry (Vaccinium corymbosum L.) cultivars and of one susceptible cultivar was manipulated during the primary infection period of mummy berry disease to determine if some portion of the observed resistance was based on disease avoidance. In experiments across 2 years, resistant cultivars either increased continually in susceptibility or exhibited a peak and then decreased in susceptibility as shoots elongated. In a larger experiment that included both susceptible and resistant cultivars, peaks of susceptibility were identified for `Bluejay', `Darrow', and `Jersey'. In contrast, general decreases in susceptibility were identified for `Duke', `Blueray', and `Croatan' as shoots elongated. Shoot lengths associated with peak susceptibility varied among and within cultivars across experiments. The increases in susceptibility observed at longer shoot lengths were generally small. This finding suggests that cultivars identified as resistant have intrinsic levels of resistance, but maturity and general condition of the plant tissue can also affect disease levels.
Carambola Quality after Ethylene and Cold Treatments and Storage
Authors: Miller W.R. , McDonald R.E.
Published: February 2019

Carambolas (Averrhoa carambola L.) must be treated with an approved insect quarantine procedure such as cold treatment before shipment to certain markets. Condition and quality of mature-green (MG) and slightly yellow (SY) fruit were determined after they were: 1) treated with ethylene at 0.1 ml·L-1 for 48 hours (C2H4), 2) subjected to cold treatment (CT) at 1 °C for 15 days, and 3) held in storage at 5 °C for 7 days plus 3 days at 15 °C. Ethylene-treated fruit were softer and yellowness was enhanced compared with non-C2H4-treated fruit. MG fruit were firmer and lost more mass following CT and storage than SY fruit. C2H4 treatment increased the severity of peel scald, stem-end breakdown (SEB), and fin browning but had no effect on pitting. CT increased the severity of scald and pitting, and the severity of SEB, but did not affect fin browning. Peel scald, pitting, SEB, and fin browning were more severe in MG than in SY fruit at the final evaluation. C2H4-treated fruit had lower total soluble solids concentration, higher titratable acidity and pH, and a less preferred flavor and texture than control fruit. We conclude that carambola fruit should be selected at harvest at the slight-yellow stage (3% to 25% of surface area) instead of at the mature-green stage. Fruit to be cold-stored should not be C2H4 treated due to enhanced mold development and severity of SEB.
Storage Temperature Affects Viability of Banksia menziesii Pollen
Authors: Maguire Tina L. , Sedgley Margaret
Published: February 2019

Storage of Banksia menziesii pollen was assessed at 20, 4, –20, –80, and –196 °C using a semisolid medium of 1% agar, 15% sucrose, 0.01% boric acid, 0.03% calcium nitrate, 0.02% magnesium sulfate, 0.01% potassium nitrate, and an incubation temperature of 25 °C. The germination percentage remained constant at ≈70% in all treatments except for pollen stored at 20 °C, which exhibited only 25% germination after 6 months. Pollen viability was assessed using fluorescein diacetate (FDA), but the results did not reflect the loss of germinability at 20 °C and correlation with in vitro results was variable. Floret position on the inflorescence did not affect germination, but pollen viability varied over the flowering period with maximum germination at midseason.
A DNA Extraction Protocol from Various Tissues in Woody Species
Authors: Cheng F.S. , Brown S.K. , Weeden N.F.
Published: February 2019

A DNA extraction protocol was developed for tissues from woody species. DNA was extracted successfully from 11 species and five different types of tissues and was suitable for RAPD and restriction analysis. Spermine precipitation was used to further purify DNA. The protocol can be used for large-scale analysis and mini-preparations.
Summer Pruning Young `Sweetheart' Sweet Cherry Trees Affects Yield and Tree Size
Authors: Kappel Frank , Bouthillier Michel , Brownlee Rob
Published: February 2019

`Sweetheart' sweet cherry trees (Prunus avium L.) were summer-pruned for four summers (1991-94) either before or after harvest and at two levels, removing 1/3 or 2/3 of current-season growth by heading cuts. In an additional postharvest treatment, some current-season growth was removed by thinning cuts. The preharvest 1/3 treatment had the highest cumulative yield during the experiment. Higher yields were obtained following preharvest than postharvest treatments, and following less severe treatments (removing 1/3 of current-season growth) than more severe (removing 2/3) treatments. These increased yields were for the early stages of orchard production. Average fruit mass was not affected by any of the treatments. The summer-pruned trees had smaller trunk cross-sectional area (TCSA) increments over the trial and their final TCSA was smaller than that of the control trees.
Boron Does Not Increase Hazelnut Fruit Set and Production
Authors: Ferrán X. , Tous J. , Romero A. , Lloveras J. , Pericón J.R.
Published: February 2019

In a 3-year experiment in two drip-irrigated orchards on the Mediterranean coast, boron (B) sprays applied at rates of 0.6 and 1.2 g per tree and a soil B application of 12 g per tree did not increase fruit set or production of Corylus avellana L. `Negret' and `Pauetet' hazelnuts with mid to low foliar B levels (14.3 to 21.8 μg·g-1 dry mass). The average fruit set and nut yields of the trials were, respectively, 66% and 3.54 kg per tree for `Pauetet', and 50% and 4.54 kg per tree for `Negret'. The lack of response to B applications might be due to 1) initial fruit set levels were high; 2) the current B recommendation guidelines (25 to 30 μg·g-1 dry mass) might be adequate for fruit set and yield; 3) the rates of B applied might be too low; and 4) weather and soil conditions, cultivars, and biennial bearing may have masked any response to foliar B application.
Gibberellic Acid and Cytokinin Affect Phalaenopsis Flower Morphology at High Temperature
Authors: Chen Wen-Shaw , Chang Hsueh-Wen , Chen Wen-Huei , Lin Yih-Shyan
Published: February 2019

Gibberellin A3 (GA3: 1, 3, or 5 (μg/shoot), 6N-benzyladenine (BA: 1, 3, or 5 μg/shoot), or both were applied to the flowering shoots of a white hybrid Phalaenopsis orchid (Leda) when they were 2 to 3 cm (stage 1, no flower primordial long at high temperature (30 °C day/25 °C night). When flowering shoots were treated with GA3, alone, deformed flowers were more frequent with increasing GA3 concentrations. The occurrence of GA3-induced deformed flowers was prevented by BA at the same dose as GA3 when applied 4 days after GA3 treatment. BA (1, 3, or 5 μg/shoot) was also applied 4 days before (time 1) or 4 days after (time 2) GA3 (1 (μg/shoot) treatment for regulating plant characteristics. The application of BA at 1 or 5 μg/shoot to stage 1 flowering shoots at time 2 resulted in short internodes between florets, whereas BA application at time 1 had no effect. Simultaneously, BA at 1 or 5 μg/shoot applied at time 1 or time 2 to stage 2 (5 to 6 cm long, two- to three-flower primordia) flowering shoots also shortened internode length between florets as compared to GA3 alone. When a stage 1 flowering shoot was given BA (3 or 5, but not 1 μg/shoot) and then treated with GA3 4 days later, flower count was slightly reduced as compared to treating with (GA3 alone. However, a high dose of BA applied at time 1 or time 2 on stage 2 flowering shoots had no effect on flower count. Chemical names used: N-(phenylmethyl)-lH-purine-6-amine [benzyladenine (BA)], gibberellic acid (GA3).
Evaluation of Fungicides and Surfactants for Control of Fairy Rings Caused by Marasmius oreades (Bolt ex. Fr.) Fr.
Authors: Blenis P.V. , Nadeau L.B. , Knowles N.R. , Logue G.
Published: February 2019

Marasmius oreades, a causal agent of fairy rings, is one of the most important pathogens of turfgrass in the Great Plains region of North America. Following in vitro and greenhouse screening of surfactants and fungicides, two organosilicone surfactants, Silwet L-77 and Sylgard, together with the fungicide chlorothalonil, were evaluated in the field. Treatments were applied to healthy and infested turfgrass (Poa pratensis L., Festuca rubra L.) in either 1992, 1993, or in both years. Plots were sampled for grass production, canopy cover, mushroom production, grass chlorophyll content, soil water content, and phytotoxicity. Typically, there were no significant fungicide effects, fungicide by surfactant interactions or differences between Silwet L-77 and Sylgard. Relative to the water control, surfactants caused an approximate 3-fold increase in grass productivity on infested plots in the year of application. However, the difference in canopy cover between organosilicone-treated and control plots tended to be much less. Applying the surfactants to diseased plots in two successive years decreased the canopy cover but had no significant effect on grass production. Chlorophyll content tended to decrease in response to surfactants regardless of whether the turf was infested or healthy. Surfactants almost completely eliminated mushroom production and greatly reduced the occurrence of mycelium. Both organosilicones increased soil water content in infested areas; differences were detectable 2 years after application. Acute phytotoxicity from the surfactants was detected in infested but not in healthy plots. There was no direct evidence of chronic phytotoxicity. Organosilicone surfactants appear to have considerable potential for the management of fairy rings. Chemical names used: oxyalkylenemethylsiloxane (Silwet L-77); 2-(3-hydroxypropyl)-heptamethyltrisiloxane (Sylgard); tetrachloroisopthalonitrile (chlorothalonil).
Evaluation of Asparagus officinalis Cultivars for Resistance to Stem Blight by Using a Novel Inoculation Method
Authors: Sonoda Takahiro , Uragami Atsuko , Kaji Kazuhiko
Published: February 2019

Asparagus officinalis L. cultivars were evaluated for resistance to asparagus stem blight caused by Phomopsis asparagi (Sacc.) Bubák under controlled environmental conditions. The plants were inoculated with the vinyl tube and cotton inoculation method. Disease severity assessments, based on the percentage of diseased plants and the disease index, were made 4 weeks after inoculation. Estimates of the percentage of diseased plants ranged from 33% to 80%, and the disease index ranged from 28 to 79. None of the cultivars and lines showed high resistance, but there were significant differences in disease susceptibility among the cultivars and lines.
Phenolic Composition, Browning Susceptibility, and Carotenoid Content of Several Apricot Cultivars at Maturity
Authors: Radi M. , Mahrouz M. , Jaouad A. , Tacchini M. , Aubert S. , Hugues M. , Amiot M.J.
Published: February 2019

Phenolic composition and susceptibility to browning were determined for nine apricot (Prunus armeniaca L.) cultivars. Chlorogenic and neochlorogenic acids, (+)-catechin and (-)-epicatechin, and rutin (or quercetin-3-rutinoside) were the major phenolic compounds in apricots. In addition to these compounds, other quercetin-3-glycosides and procyanidins have been detected. Chlorogenic acid content decreased rapidly during enzymatic browning, but the susceptibility to browning seemed to be more strongly correlated with the initial amount of flavan-3-ols (defined as catechin monomers and procyanidins). As chlorogenic acid is certainly the best substrate for polyphenol oxidase, the development of brown pigments depended mainly on the flavan-3-ol content.
Classification of Genetic Variation in Garlic (Allium sativum L.) Revealed by RAPD
Authors: Al-Zahim M. , Newbury H.J. , Ford-Lloyd B.V.
Published: February 2019

RAPD analysis was employed to assess genetic variation in named cultivars of garlic (Allium sativum L.), and to examine the relationships between cultivated garlic varieties and the wild progenitor Allium longicuspis. Twenty-seven accessions were subjected to RAPD analysis using 26 oligonucleotide primers. Of a total of 292 bands, 63 (21%) were polymorphic. Cluster analysis revealed groupings that in part reflected patterns of morphological variation. All bolting forms (including wild and cultivated) grouped separately from the nonbolting cultivars. A. longicuspis and var. ophioscorodon grouped together, indicating close taxonomic affinity. Based upon relative levels of variation within different groups, we suggest potential relationships within the A. sativum/A. longicuspis complex.
Geographic Differentiation and Embryo Type Identification in Mangifera indica L. Cultivars Using RAPD Markers
Authors: López-Valenzuela J.A. , Martínez O. , Paredes-López O.
Published: February 2019

Fifteen mango cultivars were examined using randomly amplified polymorphic DNA (RAPD) markers with decamer primers of arbitrary sequence. Thirteen of the 40 primers screened were informative and 109 amplified DNA bands were selected as RAPD markers. Specific RAPD markers for some mango cultivars were identified. Cluster analysis based on the 109 RAPD markers produced a dendrogram of the genetic relatedness of the 15 mango cultivars. `Manila' and `Carabao' were the most similar, which is in good agreement with their putative pedigrees. The four major bifurcations in the dendrogram separated correctly the genotypes into four groups according to their geographic origin. Bulk segregant analysis of polyembryonic and monoembryonic cultivars detected a specific RAPD marker for polyembryony. These markers may facilitate the management of mango germplasm for breeding purposes.
Screening Hybrid Citrus Rootstocks for Resistance to Tylenchulus semipenetrans Cobb
Authors: Verdejo-Lucas S. , Sorribas F.J. , Forner J.B. , Alcaide A.
Published: February 2019

The response of 22 citrus hybrid rootstocks to a Mediterranean biotype of Tylenchulus semipenetrans Cobb was determined in a greenhouse test. Five of the 11 rootstocks with Poncirus trifoliata (L.) Raf in their parentage did not support nematode reproduction. However, rootstocks with Troyer citrange [Citrus sinensis (L.) Osbeck × P. trifoliata (L.) Raf] in their parentage were susceptible to the nematode.
Electronic Information Systems: All That They Can Be, or Shared Development/Review/Use of Educational Information via the World Wide Web
Authors: Green James , Kjelgren Roger
Published: February 2019

In this symposium we will explore the unique capabilities, differences, and requirements of authoring and distributing information as electronic media rather than as the printed page. What is meant by “authoring for the interested learner”? How can the information base be constructed to be “inquiry driven”? Can information be developed as concise answers, chunks, or electronically digitized information packages to be used to support decisions on specific questions? What is meant by “authoring once” for use across alternative media platforms (WWW, CD-ROM, printed page) and for linkage (use) into alternative documents? How can we get groups of educators to collaborate on a “global information system”? Can we establish effective national “peer review” systems for educational information? What can we do with the current electronic information technology? What would we like to be able to do? These and other questions will be discussed by educators from diverse disciplines, ranging through library information science, education, communications, horticulture, and crop and soil science. We invite you to join us in developing this symposium (subjects, speakers) by checking its evolution under the “symposia” link at http://www.forages.css.orst.edu/AAAS-PD/ and sending your ideas by e-mail to the moderators or individual speakers.