bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF LACTIDICHLOR ETHYL AND GIRDLING ON FRUIT SET, FRUIT SIZE, AND MATURITY OF PEACH.
Authors: Maurer Michael , DeWitt Thomas , Ritenour Gary
Published: February 2019

Mature 7-year-old `Raycrest' peach trees (Prunus persica [L.] Batsch) were treated at prebloom and late postbloom with foliar sprays of lactidichlor ethyl at 0, 25, 50, 75 and 100 mg·liter-1. A trunk girdled treatment was also included. Lactidichlor ethyl treatments had no effect on fruit set, fruit size and maturity. Girdling trees 30 days postbloom increased fruit size and enhanced maturity, but had no effect on fruit set. These results suggest that fruit size and maturity are enhanced by girdling.
TRAY COLOR INFLUENCES GROWTH AND QUALITY OF LETTUCE AND TOMATO TRANSPLANTS.
Authors: Hassell Richard L. , Kretchman D.W.
Published: February 2019

Two cultivars of tomato (Lycopersicon esculentum) and leaf lettuce (Lactuca sativa) were evaluated using two plug trays, polyethylene and polystyrene in two colors, black and white. Cells were 2 cm square inverted pyramid and 5 cm deep. Temperatures 0.3 cm below the surface of the media in the black trays average 2 to 4°C warmer than in the white trays. Night temperatures were not influenced by tray color. There was no apparent interaction between color and tray composition. Tomato plants grown in black trays had longer, smaller diameter stems than those in the white trays. Total leaf area, plant fresh and dry weights, however, were not affected by tray color. Leaf lettuce grown in black trays had greater total leaf area than those in white trays. Leaf numbers were not affected by tray color. Plants of tomato and lettuce grown in white trays were shorter, stockier, and easier to handle during transplanting than those produced in black trays. Both cultivars of tomato and lettuce responded similarly to tray color and composition.
INFLUENCE OF TRANSPLANT AGE AND CONTAINER SIZE ON BROCCOLI PRODUCTION
Authors: Olson S. M. , Locascio Salvadore J.
Published: February 2019

Four experiments were conducted to evaluate the influence of transplant age and container size on `Green Duke' broccoli production. Transplant ages (weeks from seeding) were 3, 4, and 5 weeks in Exp. A, 4, 5, and 6 weeks in Exps. B and D and 3, 4, 5, and 6 weeks in Exp. C. Cell sizes were 2.0 cm (width) × 3.2 cm deep (2.0 cm), 2.5 cm × 7.2 cm deep (2.5 cm), and 3.8 cm × 6.4 cm deep (3.8 cm) with each transplant age. With the smallest container size (2.0 cm), yields were significantly lower in 3 of 4 experiments as compared to the 3.8 cm container size. In 2 of 4 experiments, yields were lower with the 2 cm size as compared to the 2.8 cm container size. In Exps. A and B transplant age did not influence yield, but use of the oldest transplants in Exp. C resulted in reduced yields while use of the oldest transplants in Exp. D resulted in the highest yields Generally, head weights followed similar patterns to the yields.
FACTORS AFFECTING THE REGENERATION OF PEPPER (CAPSICUM ANNUUM L.)
Authors: Jacobs J. L. , Stephens C. T.
Published: February 2019

Several growth hormone combinations and silver nitrate concentrations were examined for their effect on regeneration of different pepper genotypes. Primary leaf explants from in vitro seedlings were cultured on a revised Murashige and Skoog medium supplemented with auxin, cytokinin and 1.6% glucose. Combinations of different concentrations of indole-3-acetic acid (IAA), 0-5 mg/l, and 6-benzylaminopurine (BAP), 0-5 mg/l, were tested to determine the most effective medium for shoot primordium formation. Experiments with IAA and BAP did not result in a specific growth hormone combination appropriate for regeneration of all genotypes tested. Of the silver nitrate concentrations tested, 10 mg/l resulted in the best shoot and leaf differentiation and reduced callus formation. Differences in organogenic response of individual genotypes were evaluated on a single regeneration medium. Whole plants were regenerated from 11 of 63 genotypes examined. Based on these experiments, a reproducible regeneration system for pepper was developed with a total of 500 plants regenerated to date.
IN VITRO FLOWERING OF REGENERATED SPINACH PLANTS
Authors: Al-Khayri J. M. , Huang F. H. , Morelock T. E.
Published: February 2019

Regenerated spinach (Spinacia oleracea L.) maintained under a 10-h photoperiod (65 uE m-2 s-1) after an incubation period on a GA-containing medium were induced to flower in vitro. The plantlets were regenerated from callus initiated on MS medium with 2.0 mg L-1 kinetin and 0.5 mg L-1 2,4-D and were subsequently transferred to a medium containing 2.0 mg L-1 kinetin, 1.0 mg L-1 GA, and 0.01 mg L-1 2-4,D. While on the regeneration medium, the cultures were exposed to a long-day photoperiod. Regenerants were transferred to an IBA-containing medium for rooting, after which flowering was observed. In vitro flowering plantlets exhibited male and female flowers depending on the sex of the explant donor. Female plantlets developed seeds in the culture vessels. This method of seed production from regenerants can eliminate time-consuming steps in acclimation, transplanting to soil, and plant maintenance.
COMPARISON OF CELL GROWTH IN POLYPROPYLENE CULTURE BAGS VERSUS SHAKER FLASKS
Authors: Wright Daniel C. , Franzen Linda
Published: February 2019

Gyratory shakers are commonly employed to maintain oxygen levels in plant suspension cultures. Growth of plant cells in semi-permeable polypropylene bags is a potential alternative to this technique. Carrot and tobacco cell cultures were grown in stationary autoclavable polypropylene bags (AgriStar, Inc.) and 125 ml Erlenmeyer flasks on a shaker for up to 56 days. Experimental cultures were inoculated from a common source of exponentially growing cells. Measurements of cell growth were determined by measuring absorbance at 550nm and correlated with actual cell counts. The number of cells grown in polypropylene bags increased at a similar rate to cells grown in flasks during the first 35 days. After 35 days, polypropylene bag cell cultures out-performed flask grown cultures. Flask grown cultures were highly pigmented, an indication of culture senescence.
PALMETTE-LEADER (PL) AND CENTRAL-LEADER (CL) TREE-FORM EFFECTS ON LIGHT DISTRIBUTION, PRODUCTIVITY AND FRUIT QUALITY OF `McINTOSH' APPLE TREES
Authors: Elfving D.C. , Schechter I. , Cline R.A. , Pierce W.F.
Published: February 2019

Mature `Macspur McIntosh'/MM.106 trees trained to the CL tree form were converted to the PL tree form in 1987 by removal of east- and west-oriented upper scaffold limbs. Control trees were pruned to maintain the CL form. Dormant pruning in later years maintained either tree form. No summer pruning was used in this study. Canopy light levels along horizontal transects at one m above the soil and vertical transects, both through the center of the canopy, were unaffected by tree form or transect direction. Yields were significantly lower for PL trees in 1987 and 1989, while yield efficiency was reduced in PL trees in all 3 years. Fruit size, trunk cross-sectional area, and foliar macro-nutrient content were unaffected by tree form during this study. Fruit color development in both the upper and lower halves of the canopy was uninfluenced by tree form.
New Sources of Resistance to Black rot in Crucifers and Inheritance of Resistance.
Authors: Guo Z. H. , Dickson M. H. , Hunter J. E.
Published: February 2019

Resistance to Black rot was studied in B. oleracea, B. campestris and B. napus, using three different inoculation procedures. The results indicated that hydathode inoculation without wounding and the wound suspension technique were useful for differentiating levels of resistance found in B. oleracea and B. campestris, but not in B. napus. Only the wound colony method allowed differentiation between high and moderate resistance in B napus. B. napus, PI 199947 and PI 199949, exhibited the highest resistance found in cultivated Brassica species. In B. campestris, two chinese cabbage accessions showed quantitative inheritance for moderate levels of resistance. In B. napus, the high level of reistance was conferred by one dominant gene, to which the symbol Br was assigned, whereas the moderate resistance was due to one recessive gene bm.
FIELD STUDIES TO QUANTIFY POLYGENIC RESISTANCE IN SPINACH TO WHITE RUST AND DOWNY MILDEW.
Authors: Brandenberger L.P. , Morelock T.E. , Correll J.C.
Published: February 2019

Field observations indicate that polygenic resistance to downy mildew (Peronospora farinosa f. sp. spinaciae) was observed during the course of a breeding program to develop polygenic resistance to white rust (Albugo occidentalis). Field studies were initiated using five cultivars and one breeding line to quantify the level of resistance to downy mildew and white rust. Separate plots were inoculated with each pathogen at a specific spore concentration and then subjected to a minimum dew period of 12h. Infection was quantified by measuring latent period, lesion number, lesion size, sporulation and percent leaf area infected.
BREEDING STRATEGIES FOR DEVELOPING DRY BEAN CULTIVARS RESISTANT TO BRUCHID WEEVILS
Authors: Bliss Fredrick A.
Published: February 2019

The presence of arcelin protein in the seeds of common bean, Phaseolus vulgaris L., provides resistance to the Mexican bean weevil and to a lesser degree, the common bean weevil. Fast, accurate identification of single seeds containing arcelin facilitates the transfer of alleles for each of four different arcelin types through standard crossing procedures. Seed yields and other traits of near-isogenic lines that contain different alleles were comparable to the standard parent, Porrillo 70. Genotypic mixtures containing resistant and susceptible seeds produced seed yields comparable to Porrillo 70, which suggests that heterogeneous populations offer the potential for stable resistant cultivars.
DEVELOPMENT OF MULTIPLE-DISEASE-RESISTANT PLUM CULTIVARS
Authors: Norton J. D. , Boyhan G. E. , Abrahams B. R.
Published: February 2019

Plum production in the Southeastern United States is limited because cultivars are susceptible to bacterial canker (Pseudomonas syringae), bacterial fruit and leaf spot (Xanthomonas pruni), black knot (Apisporina morbosa) and plum leaf scald (Xylella fastidiosa). Evaluation of four new cultivars developed by the Alabama Agricultural Experiment Station indicated that AU-Rubrum, AU-Rosa and AU -Cherry were resistant to all the diseases listed, and AU-Amber was resistant to all excapt A. morbosa. Disease ratings were made on trees in six experimental plantings in Alabama, in Georgia test plantings and in grower trials.
MICROPROPAGATION OF SELECTED DESERT-ADAPTED SPECIES
Authors: Huang Dao-Shun , Ho Jingkun , Backhaus Ralph
Published: February 2019

Tissue culture methods have been developed for a number of desert-adapted species which have potential economic value. These species include gum tragacanth (Astragalus gossypinus), candelilla (Euphorbia antisyphilitica), guayule (Parthenium argentatum), cliff rose (Cowania stansburiana and C. subintegra), bottle tree (Brachychiton populneum), red squill (Urginea maritima), Arizona agave (Agave arizonica), and spider lily (Pancratium littorale). Axillary shoot proliferation for the dicotyledenous species of this group is induced using concentrations of 2 mg/L BAP, whereas the rooting requirements vary considerably. Micropropagation of the bulb-producing species, is accomplished by aseptic culture of bulb scales in darkness, followed by shoot proliferation of the bulblets and rooting. Micropropagation of Agave requires adventitious shoot formation from a callus intermediate followed by direct caulogenesis from subculture shoots and subsequent rooting.

The potential benefit of these desert-adapted species and the usefulness of the micropropagation procedures will be discussed.
PRE-FORCING TREATMENTS AND PLANT GROWTH REGULATORS IN THE FORCING SOLUTION PROMOTE MACRO- AND MICRO-PROPAGATION OF WOODY PLANT SPECIES
Authors: Yang Gouchen , Read Paul E.
Published: February 2019

BA, IBA and GA3 were incorporated into softwood tissues to be cultured in vitro or rooted as cuttings by adding the plant growth regulators (PGR) at various concentrations to a forcing solution containing 200 mg/l 8-hydroxyquinoline citrate and 2% sucrose. BA and GA3 helped break bud dormancy in autumn-collected stems and increased percent bud-break. IBA inhibited bud break and shoot elongation. Rooting of forced softwood cuttings was enhanced by IBA in the forcing solution, while GA3 inhibited the rooting of plant species tested. When dormant stems were forced with periodic additions of BA (10 mg/l) in the forcing solution, in vitro shoot proliferation was enhanced. However, inclusion of GA3 in the forcing solution reduced shoot proliferation. A pre-forcing NaOCl soak and a pre-forcing treatment with wetting agents accelerated bud break, size and number of shoots available for both micro- and macro-propagation of the woody plant species tested. The forcing solution protocol described is an effective PGR delivery system and it can be used by the propagator to extend the season for obtaining softwood growth suitable for use as in vitro explants or softwood cuttings.
LONG-TERM CONTROL OF TREE GROWTH IN UTILITY RIGHTS OF WAY USING GROWTH REGULATORS
Authors: Klingaman Gerald L. , Wheeler G. Laurin
Published: February 2019

Twelve to 15 year old silver maple and wild cherry trees were top pruned severely to a height of 5m and then trunk injected with Prunit 20g/l at 0, 0.1, 0.5 or 1.0 g/inch of trunk diameter or were treated with a trunk pour of Prunit 50W at the rate of 0, 0.5 or 1.0 g/inch of trunk diameter. Treatment effects were not obvious on any trees until 12 months after treatment. After 36 months maples receiving the two highest rates had made less than 50 cm of growth above the pruned top of the tree whereas the untreated control had produced 3 m of new shoot growth. The 0.1 g rate produced less aesthetic disruption to the appearance of the tree and reduced growth to 1.2 m. Wild cherry trees responded similarly but the amount of regrowth following pruning was less. Maple trees receiving the trunk pour treatment exhibited a 50% reduction in new shoot growth 36 months after treatment.
A HANDS-ON GRADUATE EXERCISE IN HORTICULTURAL PLANT AND ENVIRONMENTAL RESEARCH METHODS
Authors: Spomer L. Art , Knight Sharon L. , Smith Mary Ann Lila
Published: February 2019

Horticulture Research Methodology courses are an important if not essential introduction to research for beginning graduate students. Such courses are often characterized by presentation of a series of experimental techniques, lacking continuity and out of context with real-world research situations. In the described course, students gained expertise with a range of environmental and plant measurement techniques within the framework of a semester-long experiment. The experimental techniques were introduced and incorporated into the experiment at appropriate stages. Each student engaged in hands-on participation in development of a proposal; experimental set up, implementation, and daily maintenance; and data accumulation, analysis, and reporting (in HortScience manuscript format). In addition to direct experience with all subject techniques, each student had individual responsibility for characterization of a. selected plant (or environmental) parameter. This format successfully accomplished the provision of direct and coherent experience with a wide variety of important horticultural research techniques within a real-world setting.
BRIDGING THE GAP: EDUCATION TO EMPLOYMENT
Authors: Baker Cynthia L.
Published: February 2019

With the growing emphasis on research and a continuous crunch for space, practical “lab” training available for many students is scarce or declining. Though our horticulture graduates are quite knowledgeable, their “hands-on” experience is often very limited. This places them at the bottom of the job ladder even though they have been educated for more advanced positions. It's difficult to recruit students into 4-year degree programs when starting salary is barely above that of a high school graduate. We can enhance the students marketability through experiential education by tapping the resources of the horticultural industry before they graduate. Through internships and `co-op” students get the practical training and experience they need to qualify for better paying and more challenging jobs. It's an old concept, but one that is underutilized by both students and advisors.
EFFECT OF TIME/TEMPERATURE TREATMENTS ON PHENYLALANINE AMMONIA-LYASE ACTIVITY AND DEVELOPMENT OF RUSSET SPOTTING IN ICEBERG LETTUCE
Authors: Ritenour M.A. , Saltveit M.E. , Ahrens M.J.
Published: February 2019

Russet spotting (RS) is an important postharvest disorder in Iceberg lettuce (Lactuca sativa L.). Previous studies showed that RS is induced by exposure to ∼5 ppm (ul/l) ethylene at ∼5C for 3 days and is characterized by the appearance of 1 to 2 mm diam. oval, brown sunken spots along the midrib. Increases in phenylalanine ammonia-lyase (PAL) activity and phenolic content are highly correlated with RS development. Ethylene-induced PAL activity is much less at higher (12C) or lower (0C) temperatures. In this study isolated whole leaves were exposed to a log series of ethylene concentrations from 0.1 to 10 ppm at temperatures from 0.0C to 20C for up to 8 days. Tissue was transferred among these various treatments to investigate the kinetics of PAL induction, activity and deactivation, phenolic accumulation, and RS development. A subjective evaluation was then made of RS development using a 1 to 9 scoring system in which 1 was no RS, and then PAL activity and phenolic content were measured. Preliminary results indicate that ethylene-induced PAL activity was decreased more rapidly upon transfer to temperatures above 10C than to 0.0C. Accumulation of phenolic compounds and development of RS paralleled each other, and were positively related to PAL activity. Practical implications of these results will be discussed.
TIME OF FRUIT REMOVAL INFLUENCES RETURN BLOOM IN PECAN
Authors: Reid William
Published: February 2019

Pecan trees, Carya illinoensis, often exhibit a strong alternate bearing pattern. The presence of a heavy seed crop inhibits terminals from fruiting the following season. This study was developed to discover at what point in the development of the pecan fruit does this inhibition take place. Six nut removal times were evaluated: (1) after pollination but before fertilization, (2) one-half ovule expansion, (3) full ovule expansion or water stage, (4) dough stage, (5) 3 weeks after the initiation of the dough stage, and (6) no fruit removal until harvest. The cultivar `Mohawk' was used for this randomized block experiment.

Return bloom was significantly enhanced by the removal of fruit prior to the initiation of kernel filling (dough stage). Less than 10% of terminals that supported pecans through the dough stage were able to produce distillate flowers the following year. Twig mortality was significantly higher for terminals that completed kernel filling. These results indicate that nut thinning prior to the water stage may reduce the alternate bearing tendency in pecan.
PRUNE OVULE LONGEVITY: EFFECT OF CULTIVAR AND FALL-APPLIED ETHEPHON
Authors: Moreno Yerko M. , Miller Anita Nina
Published: February 2019

Some cultivars of prune (i.e. `Brooks') consistently set good crops while others (i.e. `Italian') are erratic bearers. Fall-applied ethephon increases fruit set. Ovule longevity has been hypothesized to be an important factor in fruit retention. The effects of the cultivar and fall ethephon application on ovule longevity were determined.

Ethephon (0 and 500 mg·l-1) was applied to `Italian' and `Brooks' prune trees at the 50% leaf drop stage. The following spring, flower buds were emasculated and covered to prevent pollination. Ten flowers were sampled every two days from anthesis until 20 days after anthesis (DAA). Flowers were fixed in FAP and ovule longevity determined using fluorescence microscopy. Ovule longevity was longer in `Brooks' than `Italian'. At 20 DAA, all of the `Brooks' flowers still had viable ovules. Only 40% of the `Italian' flowers had viable ovules. The `Italian' flowers excised from ethephon-treated trees had at least one non-senescent ovule at 17 DAA. Ethephon prolonged ovule longevity in `Italian' prune flowers. No effect of ethephon was observed on the ovule longevity of the `Brooks' prune.
POTASSIUM CHLORIDE CONCENTRATION DURING PRODUCTION AFFECTS TOMATO TRANSPLANT RESPONSE TO POSTPRODUCTION WATER STRESS
Authors: Williams James D. , Kretchman D.W.
Published: February 2019

Transplants of `Ohio 8245' tomato grown in 48-cell plastic trays received 5 potassium chloride concentrations and were stressed by withholding water during the 6th week of growth. Gravimetric water loss differed between treatments with decreased water loss associated with increased potassium chloride concentration. As water was withheld, incidence of wilt was greater and more evident at an earlier stage with plants supplied with lowering KCL concentrations. Root and shoot dry weights, plant height and leaf area were not affected by treatments. This indicates an apparent increase in water use efficiency in tomato transplants supplied with KCL at greater concentrations than supplied under standard fertilizer regimes.
POTASSIUM SOURCE AND RATE AND CALCIUM RATE EFFECTS ON TOMATO YIELD AND QUALITY.
Authors: Locascio S. J. , Olson S. M. , Gull D. D.
Published: February 2019

Tomatoes (Lycopersicon esculentum Mill.) were grown on a sand and loamy sand to evaluate the effects of K source, K rate, and Ca rate on plant nutrient uptake, fruit yield, and fruit quality. The K was applied at 200 and 400 kg K·ha-1 from KCl and K2SO4. Gypsum was applied at 0, 450 and 900 kg Ca·ha-1. On the sand, tomato N leaf tissue concentrations were higher with K2SO4 than KCl. Leaf K concentrations were higher and Ca contents were lower with the higher than lower K rate. At first fruit harvest, leaf Ca concentrations were linearly increased with an increase in Ca rate. Early and total fruit yields, however, were not influenced by K source, K rate, or Ca rate at both locations Marketable fruit were more firm with K2SO4 than KCl and with 200 than 400 kg K·ha-1 on the sand. Fruit were less firm on the sandy loam than sandy soil but was not affected by K source or rate on the former soil. Ca rate had no effect on fruit firmness on either soil. Fruit citric acid contents were higher with KCl than K2SO4 and with 400 than 200 kg K·ha-1, Fruit color and percentage dry weight were not affected by treatment.
ASYMMETRIC PROTOPLASM FUSION IN TOMATO
Authors: McCabe P.F. , Dunbar L.J. , Guri A. , Sink K.C.
Published: February 2019

Sexual hybrid plants of Lycopersicon esculentum × L. pennellii (E × P) have been transformed and the T-DNA inserts genetically mapped. Donor protoplasts of E × P were isolated from leaves, and subsequently irradiated with 0, 5, 10 and 20 krad of a 60Co. They were then fused with suspension-derived protoplasts of S. lycopersicoides using the PEG-CA++-high pH technique. The protoplasts were cultured in medium 8E at 1.5 × 106 protoplasm/ml. Selection of heterokaryon-derived macrocalli was facilitated by the inability of irradiated donor protoplasts to divide and by plating p-calli on regeneration medium containing kanamycin - an antibiotic for which the resistance gene NPTII is part of the T-DNA. Morphological characteristics of the resulting asymmetric somatic hybrid plants indicate that 10 and 20 krad irradiation eliminates a larger port ion of the genome than does 5 krad. This has been confirmed with isozyme analysis and chromosome counts which generally show the 5 krad asymmetric somatic hybrid plants to differ little from symmetric hybrids although they contain some significant exceptions. Isozyme data reveals the 10 and 20 krad plants to have received much less of the donor genome. Exact quantification is continuing using isozyme markers, chromosome counts and cDNA probes.
INTERFERENCE OF BLACK AND EASTERN BLACK NIGHTSHADE WITH TRANSPLANTED TOMATOES.
Authors: McGiffen Milton E. , Masiunas John B. , Huck Morris G.
Published: February 2019

Eastern black nightshade (Solanum ptycanthum) and black (Solanum nigrum) nightshade are difficult to control in tomato, interfering with harvest and decreasing fruit quality and yield. In irrigated tomatoes, soil water depletion was greater as nightshade density increased. However, tomato yield loss due to black nightshade was greatest at the lower weed densities. As density increases, photosynthetic activity (photosynthetic rates, stomatal conductance, intercellular CO2 concentration, and stomatal resistance) of black nightshade is more affected than eastern black nightshade. Photosynthetic activity of tomato is the least affected. In greenhouse experiments where water was denied for approximately a week prior to measurement, tomatoes were more sensitive to water stress than were nightshades. Nightshades were more adapted to drought stress than were tomatoes.
CORRELATION AMONG CHANGES IN THE NUCLEAR MAGNETIC RESONANCE IMAGE OF RIPENING TOMATO FRUIT AND OTHER RIPENING PARAMETERS
Authors: Saltveit M.E.
Published: February 2019

Tomato fruit undergo an orderly series of physiological and morphological changes as they progress from mature-green (MG) to red-ripe. Fruit are commercially harvested at the MG stage, a stage which often encompasses fruit of varying degrees of maturity. The ability to predict the time required for MG fruit to ripen would reduce variability in experiments and could be commercially used to pack fruit that would ripen uniformly. Nuclear magnetic resonance (NMR) imaging can nondestructively measure internal changes associated with plant growth and developmental. In this study, NMR images were taken of freshly harvested tomato fruit (Lycopersicum esculentum cv. Castlemart) at different stages of maturity and ripeness. Measurements were also made of the stage of ripeness, rate of respiration and ethylene production, lycopene and chlorophyll content, density of the pericarp wall, and condition of locular tissue. NMR images showed substantial charges in the pericarp wall and locular tissue during maturation and ripening of tomato fruit. However, it was difficult to objectively evaluate these visual changes with other ripening parameters. For example, increased lightness and graininess of the pericarp wall image was associated with a decrease in wall density; while lightening of the locular image was associated with tissue liquefacation. Use of NMR imaging in studies of tomato fruit ripening will be discussed.
MODIFIED ATMOSPHERE PACKAGING (MAP) OF BELL PEPPER FRUIT
Authors: Gonzalez Gustavo , Tiznado M.
Published: February 2019

The objective of this work was to evaluate the effect of individual seal-packaging using low density polyethylene films and waxing treatments on the storage ability and quality of Bell pepper fruit. The fruits were packaged in two kinds of films, waxed and unwaxed and kept at 10°C and 75% RH for 46 days. Characteristics of the films (Thickness and permeability for O2 and water vapor) were determined. Atmosphere changes (O2 and CO2) inside the packages were followed each 5 days. Fruits were evaluated every 10 days, for changes in color, % chlorophyll, texture, soluble solids, acidity, PH, weight loss, % decay and sensory characteristics. The activity of ADH enzyme was used as an indicator of anaerobiosis. MAP + waxing significantly delayed fruit ripening, reduced the losses of chlorophyll, weight, firmness and % of decay respect to the unwaxed and unwrapped fruits (control) and did not result in any abnormal flavors after 20, 30 and 40 days at 10°C. These quality factors demonstrate that MAP + waxing can be used to prolong the shelf life for up to 20 days without affecting the eating-quality of the fruit.
THE EFFECT OF CHITOSAN COATING ON THE SHELF-LIFE OF GREEN PEPPERS AND CUCUMBERS.
Authors: El Ghaouth Ahmed , Arul Joseph , Ponnampalam Rathy , Castaigne Francois
Published: February 2019

The effect of chitosan coating on green peppers and cucumbers stored at 13°C and 85% R.H. on weight loss, quality and respiration was assessed. Chitosan coating markedly reduced the weight loss of both green peppers and cucumbers, with greater effect at higher concentration. In addition, color loss, wilting, decay and respiration was significantly lower in coated fruits than in the control.

The results of this study indicate that the mechanism by which chitosan coating delay senescence in green peppers and cucumbers is more likely due to its ability to alleviate water stress than to modify the internal microatmosphere.
EFFECTS OF STORAGE ON TEE GERMINATION AND VIGOR OF MUSKMELON SEEDS FROM DIFFERENT STAGES OF DEVELOPMENT
Authors: Welbaum Gregory E.
Published: February 2019

It is unclear from previous reports whether muskmelon seeds require an afterripenig period to attain maximum germinability and vigor. In the current study, seeds ranging in age from 30 to 60 days after anthesis were stored at water contents ranging from 3 to 15% and at either 6 or 30°C to determine whether seed vigor increased during storage. Changes in vigor were assessed by conducting monthly germination tests on blotter papers saturated with water or polyethylene glycol solutions of known water potential. The germination percentages of immature seeds (30 and 35 DAA) were dramatically improved by 3 months of storage at low water content and temperature, while the mean time to germination and the variability of germination were reduced for all stages of development. Germination percentages in water decline after storage at high water content and temperature with immature seeds showing a greater rate of decline than mature seeds but at reduced water potentials, the same adverse storage conditions increased the germination percents es and rates of mature seeds. However prolonged storage under adverse conditions, resulted in a gradual decline in water stress tolerance. Afterripening occurred over a wide range of storage conditions and significantly improved seed vigor, particularly in immature seeds. Furthermore, the increases in vigor achieved from afterripening treatments were remarkably similar to the increases in vigor attained through priming. Priming may substitute for the afterripening requirement of muskmelon seeds.
FRUIT QUALITY DEVELOPMENT OF `GRANNY SMITH' APPLES IN RESPONSE TO TREE CANOPY LIGHT MICROCLIMATE.
Authors: Izso Elena , Larsen Fenton
Published: February 2019

A preliminary study suggested light distribution (400-700nm) did not change from terminal bud set (July) to harvest (9/9/88). Therefore, limbs of 5-year-old trees were shaded the last 90 days of the season in 1988 and 7-year-old trees were shaded the last 60 days in 1989 with 30, 63, 95% or no shadecloth. Medium (63%) and heavy (95%) shade decreased fruit weight both years. Fruit soluble solids (SSC) decreased with increasing shade in 1988 but not in 1989 until after 60 days of storage. Fruit peel chlorophyll (chl) declined with time for all treatments. Apples from full sun and heavy shade treatments had the lowest chl and visually appeared the lightest. Evidence from both years suggested there was an optimal light level between 37-70% full sun for maximum fruit color and chl. Link of 7-year-old trees were shaded at intervals, light all season, mid-season and late season. Fruit weight and firmness were not affected by time of shading. SSC was liner for mid-season shaded fruit. Chl was highest for late season shaded fruit but differences evaporated by 90 days of storage.
STUDIES ON PAPAYA PRODUCTION IN MIDDLE GEORGIA
Authors: Yadava U. L.
Published: February 2019

Three exotic lines (Dwarf, L-45, and L-50) of precocious papaya (Carica papaya L.) from India, were grown in nursery rows at the Fort Valley State College Agricultural Research Farm during 1986-1990. Performance of these lines was evaluated for their adaptation and production feasibility under the growing conditions of Middle Georgia. Two lines (L-50 and Dwarf papaya) showed a less satisfactory overall performance than did L-45, which had the highest female to male ratio (7:3) and abundantly produced tree-ripened fruits under cold protection frames during 1989 and 1990. Tree growth and survival for L-45 were greater than those for L-50 and Dwarf papaya lines. Two-month-old greenhouse-grown seedlings when established in the field in April, flowered in 60 to 65 days following transplanting. Under Georgia conditions, fruits ripened on trees in approximately 150 days after fruit set. During 1989-90, the fruit size on L-45 trees varied from 574 g to 2,286 g (mean 1,530 g) with an average of 22.5 fruits per tree. Four years data suggest that papaya can be a successful annual crop if shelter is provided during late fall to protect ripening fruits and trees from frost/cold.
FACTORS INFLUENCING PREHARVEST FRUIT SPLITTING IN ELLENDALE (C. reticulata).
Authors: Rabe Etienne , van Rensburg Piet , van der Walt Hennie , Bower John
Published: February 2019

Preharvest fruit splitting (PFS) is a serious problem in Ellendales, especially in hot, humid climactical areas. In control unsprayed treatments PFS can vary from 14 to 30% of the final yield. Any treatment during the fullbloom (FE) period aimed at increasing fruit set (gibberellic acid (GA) sprays, girdling), increases PFS levels, ranging from 40 to 60% of the final yield. This relates to a significant shift (delay) in the normal fruit drop pattern as compared to untreated trees.

We have evaluated various approaches aimed at reducing PFS in Ellendales: potassium treatments, from 10 weeks pre-blossom to six weeks after full-bloom, however, increased PFS levels, possibly due to increasing the initial fruit set levels; flower thinning, both chemical and mechanical, marginally reduced PFS, without adversely affecting yield; post-November drop GA application, 2,4-D and girdling treatments, aimed at stimulation of rind growth (not quantified) increased yields significantly (P<0.05) without concurrent increases in PFS.

Cross pollinated trees, and resultant high seed content in the fruit, yielded fruit with thicker rinds, with little or no PFS. GA application at FE reduced fruit seed content and peel thickness and increased PFS.

Any treatment causing high initial fruit set increases PFS. Flower: flower and fruit: fruit competition should be reduced early during the fruit growth phase, without adversely affecting final yields.
CLASSIFICATION OF STRESS-INDUCED SPATIAL VARIABILITY IN NEAR-INFRARED CANOPY REFLECTANCE.
Authors: Stutte Gary W.
Published: February 2019

A digital video camera (Panasonic Industrial Co., Secaucus, NJ) with a 1.7 cm charged coupled device detector (574 (h) × 499 (v) pixel elements) was modified with a custom made FRF-700 band pass filter to visualize canopy reflectance in the near-infrared (NIR) from 700 to 1100 nm. Images of canopy reflectance under a range of environmental stresses were obtained from peach and apple trees under greenhouse and field conditions. Individual video frames were digitized with Image Capture and Analysis System (Agri Imaging Systems, Inc., Fayetteville, AR). Image contrast was increased with digital equalization and filtering before classification into one of five stress levels. There was a high correlation (r2 > 0.8) between leaf stress and canopy reflectance in both apple and peach at distances < 5 meters. Spatial variability in stress-induced NIR reflectance could be detected and classified at vertical distances from 150 to 500 M. Analysis of vertical imagery revealed sections of the orchard which were most susceptible to environmental stress.
SCREENING ALMOND CULTIVARS FOR OZONE SUSCEPTIBILITY
Authors: Retzlaff William A. , DeJong Ted M. , Williams Larry E.
Published: February 2019

Uniform nursery stock of five almond cultivars (Prunus dulcis Mill., cv Nonpareil, Mission, Carmel, Butte, and Sonora) propagated on peach (P. domestica L. Batsch.) rootstock were planted in open-top fumigation chambers on 19 April 1989 at the University of California's Kearney Ag Center located in the San Joaquin Valley of California. The trees were exposed to three atmospheric ozone partial pressures (charcoal filtered air, ambient air, or ambient air+ozone) from 1 June to 2 November 1989. The mean 12-h (0800-2000 h) ozone partial pressure measured in the open-top chambers during the experimental period averaged 0.038, 0.060, and 0.112 μPa Pa-1 ozone in the charcoal filtered, ambient, and ambient+ ozone treatments, respectively. Leaf net CO2 assimilation and cross-sectional area growth of Nonpareil trees were reduced by increasing atmospheric ozone partial pressures, but Mission trees were unaffected. Foliage of Nonpareil almond abscised prematurely in the ambient and ambient+ozone treatments. The susceptibility of the Butte, Carmel, and Sonora almond cultivars to ozone was intermediate between the Nonpareil and Mission cultivars.
CLONAL PROPAGATION OF LIATRIS PYCNOSTACHYA MICHX BY IN VITRO CULTURE OF AXILLARY BUDS
Authors: Tawfik Azza , Read P. E. , Salac S. S.
Published: February 2019

A method is described for obtaining explants free of bacterial contamination and for clonal propagation by in vitro culture of liatris axillary buds. Axillary bud growth was stimulated by removal of the shoot tips of greenhouse grown stock plants. Prior to using this approach, extreme bacterial contamination occured when explants were taken from stock plants that had not been decapitated. However, these axillary buds (0.3-0.5 cm long) were successfully established free of bacterial contamination when excised, surface disinfested and cultured on Murashige & Skoog (MS) medium supplemented with various levels of benzyladenine (BA) or kinetin and gibberellic acid (GA3). The highest number of leaves and greatest shoot length were produced by buds cultured on a medium supplemented with 1.0 mg/l BA plus 1.5 mg/l GA3. Shoot number was increased on medium containing 1.0 or 2.0 mg/l BA plus 0.5 mg/l GA3. Kinetin significantly increased the leaf number of the buds but there was no effect of kinetin on the shoot length or number. Shoots formed roots in a medium supplemented with 3 mg/l indole-3-butyric acid (IBA) plus 9 mg/l GA3. The plantlets were transferred to vermiculite and acclimatized successfully under intermittent mist in a greenhouse.
TISSUE CULTURE OF CUPHEA GLUTINOSA CHAM. & SCHLECHT.
Authors: Sultanbawa Fazal , Phatak Sharad C. , Jaworski Casimir A.
Published: February 2019

Caphea glutinosa is a herbaceous, low-growing annual, bearing numerous attractive purple flowers and has potential as an ornamental and as a ground cover. Plants exhibit winter hardiness in USDA plant hardiness zone 8. Tissue culture techniques were developed to obtain large numbers of uniform plants. Whole leaf explants (approximately 1.0 cm2) callused profusely in MS (Murashige and Skoog, 1962) medium containing 84 mM sucrose, 1% (w/v) Difco Bacto agar and 8.8 μM N6benzyladenine. Shoot formation from calli was observed in the same medium 4 weeks after explanting. Detached shoots were rooted (100%) in half strength MS medium and rooted shoots were transferred to Promix® in the greenhouse 2 weeks after rooting. Tissue cultured plants flowered after 60 days in the greenhouse and no phenotypic differences were observed in floral or foliar characteristics.
IN VITRO ROOTING OF PINUS STROBUS AND THUJA OCCIDENTALIS `HETZ'S WINTERGREEN' AS INFLUENCED BY ANTIGIBBERELLIN COMPOUNDS (ANCYMIDOL AND FLURPRIMIDOL).
Authors: Burkhart Len , Meyer Martin , Dorner S.
Published: February 2019

Rooting of shoots from in vitro culture of most conifers can be difficult. An antigibberellin, ancymidol, has been shown to promote rooting of in vitro proliferated shoots of asparagus clones, but it has not been tested on conifers. Ancymidol and flurprimidol was tested for rooting on established cultures of Lake States white pine (Pinus strobus). Pulse treatments containing 5 uM ancymidol and 0.5 uM NAA gave 43% rooting, while pulse treatment with 0.5 uM NAA resulted in 7% root formation. Flurprimidol also stimulated root formation on white pine shoots, but was less than ancymidol. Thuja occidentalis `Hetz's Wintergreen' formed roots on 87% of in vitro proliferated shoots when given a pulse treatment with 5 uM ancymidol and 50 uM NAA. Shoots initiated an average of 10 roots after 60 days on vermiculite containing 1/2 liquid MCM medium.
EFFECTS OF MICROPROPAGATION TECHNIQUES ON GROWTH. AND DEVELOPMENT OF MINIATURE ROSES.
Authors: Chu C.Y. , Knight S.L.
Published: February 2019

An efficient micropropagation system is being investigated to produce low cost and high quality miniature rose plants. Dormant literal buds of miniature roses were cultured on media containing MS, 30 g·l-1 sucrose, 8 g·l-1, and 25 combinations of NAA and BA. Initial explant growth was achieved on a medium containing NAA at 0.001-0.01 ppm and BA at 0.1 ppm. The highest multiplication rate was achieved when explants were subcultured on a medium containing MS, NAA at 0.01 ppm, BA at 2 ppm, and sucrose at 30 g·l-1. Growth was enhanced after culturing when dormant buds had more parental stem tissue. In addition, explants from the lowest two nodes with the shortest internode length exhibited the poorest growth. The higher the photosynthetic photon flux (PPF) (5 to 40 μmol·s-1m-2), the more quickly explants grew and aged. The most optimal PPF for initial growth was 20 μmol·s-1m-2. Subculture microcuttings of one cm or more in length grew vigorously one month after cuttings were dipped in 1000 ppm IBA and placed on a mist bench. Our results indicate that micropropagation of miniature roses has high potential for use in commercial industry.
BENZYL ADENINE UPTAKE AND METABOLISM DURING PETUNIA SHOOT ORGANOGENESIS
Authors: Auer Carol , Cohen Jerry D. , Cooke Todd
Published: February 2019

The uptake and metabolism of exogenous tritium-labelled benzyl adenine was studied during the shoot induction period of petunia leaf explants in tissue culture. Transfer experiments with Petunia `MD1' leaf explants (1 cm2) on MS media with 2.2 uM BA show that 27% and 100% of the leaf explants are committed to shoot induction on days 6 and 10, respectively. To study BA uptake and metabolism, leaf explants were placed on media containing tritium-labled BA for 1, 3, 6 and 10 days. BA was taken up from the media on days 1-6. BA metabolizes were analyzed using HPLC, a UV absorbancc detector and enzymatic techniques. Metabolizes produced include: BA, BAdo, BA 7G, BA 9G, BAdoMP, BAdoDP, BAdoTP and 3 unidentified compounds. BA and BAdo were detected on days 1 and 3 but not during day 6-10, the time of shoot induction. The pool of ribotide metabolites decreased from days 1 to 10, from 26.5% of all metabolites to 1.6%. Glucosylated compounds, BA 7G and BA 9G, increased continuously from 24.9% to 69.8% between days 1 and 10. An unidentified compound C increased from 13% on day 3 to 24.8% on day 10. In separate experiments, BA uptake and metabolism were compared in two Petunia hybrida lines, St40 and TLV1, with different shoot organogenic responses in tissue culture. These data show interesting patterns of BA metabolism in relationship to shoot induction and organogenesis.
ROLE OF CARBOHYDRATE DEPLETION AND ETHYLENE IN FLOWER BUD ABSCISSION OF HIBISCUS ROSA-SINENSIS L.
Authors: Poole Barbara C. , Nell Terril A. , Barrett James E.
Published: February 2019

Premature flower bud abscission imposes a serious limitation on longevity of potted Hibiscus in interiorscape situations, Ethylene is known to be one causative factor. Past research has suggested that carbohydrate depletion of buds may also be involved,

A series of experiments was conducted to examine the relationship between carbohydrate levels and ethylene sensitivity of flower buds under low irradiance levels. Two cultivars were used: `Pink Versicolor', which is very susceptible to bud abscission, and the more resistant `Vista', In the first experiment, plants were harvested twice weekly after placement in interiorscape rooms (8.5 μmol m-2 s-1 for 12 hrs per day; 26.5°C day/night) until all buds had abscissed. At each harvest, buds from four size groups were collected for analysis. In the second experiment, source/sink strength of buds was manipulated by selective daily removal of certain sized buds. Remaining buds were collected just prior to abscission for analysis. In two additional experiments, `Pink Versicolor' plants were treated with either silver thiosulfate or ethephon prior to placement in interiorscape rooms. Plants were harvested twice weekly and buds collected. For all experiments, bud dry wt, total soluble sugars and starch content were determined.
CONTROL OF ERWINIA CAROVORA (AROIDEAE) ON ZANTEDESCHIA
Authors: Kemp-Glass Marihelen
Published: February 2019

A major problem in the pot production of Zantedeschia (Calla Lillies) is the bacterial soft rot Erwinia carotovora. Sometimes if the corn is infected there may be no symptoms until the plant falls over. This disease can destroy an entire crop very quickly. Z. albomoculata, Z. Elliottiana', Z. Solfatare; and Z rehmannii were soaked for 5 minutes and 10 minute in 50 ppm and 100 ppm respectively in Agrox Strep a combination bactericide and fungicide. The 50 ppm for 5 minutes gave sufficient control of soft rot provided the plants were not overwatered. However, if overwatered the incidense of soft rot did reoccur. This was controlled by watering the plants every 10 days with 50 ppm of Agrox Strep.
FUMIGATION OF TABLE GRAPES WITH DECCODIONE SMOKE TABLETS FOR PROLONGING THE POST HARVEST STORAGE LIFE
Authors: Ahmedullah M. , Dave B. , Patterson M. E , Sales M. A.
Published: February 2019

Table grapes cvs. Flame Seedless, Black Monukka and Canadice were fumigated with 2 levels of Deccodione smoke tablets for 30 minutes. Grapes were packed in TKV lugs with Botrytis inoculum planted among the clusters and stored at 0° C for up to 9 weeks. Size of smoke particles was determined. Fruit was evaluated at weekly intervals for decay and quality parameters. Deccodione residues on fruit were determined and found to be within acceptable limits set for this chemical. It was possible to store the grapes for up to 4 weeks at 0° C in good condition. Beyond this period effect of fumigation was lost. There was no bleaching of pigments around the capstem as is seen with sulfur dioxide fumigation. Storage for prolonged periods will necessitate increasing the dose of Deccodione tables and/or repeating the fumigation.
YIELD AND POD DISTRIBUTION OF CAYENNE PEPPERS AS AFFECTED BY PLANTING DENSITY
Authors: Friend Heather H. , Decoteau Dennis R.
Published: February 2019

The effect of planting density on yield and pod distribution of cayenne pepper (Capsicun annuum var. annuum L. cv. Carolina Cayenne) was investigated in a two year study. In 1988, planting density was adjusted by altering the in-row spacing of single row beds, while in 1989 planting density was adjusted by altering both in-row spacing and number of rows per bed. In-row spacings evaluated in 1988 were 60, 45, 30, and 15 cm, while in-row spacings of 60, 30, and 15 cm in single and double rows were evaluated in 1989. In 1988, pepper plants grown in the highest density (15 cm in-row spacing) produced less fruit per plant, but more fruit per hectare than those grown in lower densities. In 1989, greatest yields per hectare were recorded with either 15 cm in-row spacings with single rows per bed or 30 cm in-row spacings with double rows per bed, In general, greater percentages of fruits were located in the upper part of the plant canopy when planted in higher plant densities.