bluuebunny/crossref_metadata_2025 huggingface dataset:
792 PB 036 EFFECT OF ROOTSTOCKS ON SHOOTGROWTH. BERRY QUALITY. AND YIELD OF “FUJIMINORI” GRAPES TREATED WITH GIBBERELLIC ACID
Authors: Kubota N. , Takigawa H. , Ri X. , Yasui K.
Published: February 2019

Shoot and berry growth, sugar. titratable acidity, and anthocyanin contents of berries and crop yields of “Fujiminori” grapes (Vitis vinifera × V. labruscana) were determined in vines grafted 10 eight different rootstocks: 3309, 3306, 101-14. 5BB. 5C, 8B. SO4, and 420A. Three-year-old vines of 5BB stock and S-year-old vines of each of the other stocks grown in an unheated plastic house were used for this investigation.

Shoot growth was more vigorous on vines grafted to 5BB compared to 3309, SO4, and 8B. The highest yield per unit area was observed in vines grafted to 3306. followed in order by 5BB, 3309, 101-14, SO4, 5C, 8B, and 420A. The largest berry size was observed in vines grafted to 3306, followed by 5BB, 101-14, 3309, 8B, 5C, SO4, and 420A. Berries of vines grafted to 420A and 5BB had the highest tota1 soluble solids, followed in descending order by 8B, 101-14. and 5C. Titratable acidity of berry juice was lowest in vines grafted to 420A. The anthocyanin content of berry skin was higher in vines grafted to 420A and 101-14 than in berries of other stocks. GA-treatment did not increase the percentage of seedless berries of this cultivar to a commercially acceptable level for any of the rootstocks used.
795 PB 065 MEASUREMENT OF INCIDENT LIGHT ON GRAPE CLUSTERS USING PHOTO-SENSITIVE PAPER AND IMAGE ANALYSIS
Authors: Price Steven F. , Schuette Marc L. , Tassie Elizebeth
Published: February 2019

Digital imaging and analysis was used to quantify and characterize the light exposure patterns of photo-sensitive paper tubes placed in representative cluster postions in two grape (Vitis `vinifera L.) canopies: a minimally pruned and a vertically trained canopy. Blue pixel values of the captured video images had a strong negative correlation with the log of irradience from an integrating quantum sensor (R2=0.9308). Histograms of incident light distribution on individual paper tubes were developed using imaging software. Histograms were able to quantify the spatial distribution of light on individual tubes and were clearly related to exposure in the canopy. Average population curves of light distribution were able to differentiate the typical cluster light environment in the two canopies. Tubes in the minimally pruned canopy had a larger proportion of their surface exposed to irradiences greater than 50 μmol s-1m-2 and 65% higher average irradience than the vertical canopy. Image analysis of photo-sensitive paper appears to he a workable method to record variation in spatial and temporal light in plant canopies.
809 PB 147 STORAGE CONDITIONS AFFECTING QUALITY LOSS OF `FLAME SEEDLESS' GRAPES
Authors: Gardea Alfonso A. , Martinez Miguel , Sánchez Alfonso , Báez Manuel , González Gustavo
Published: February 2019

Weight loss and dehydration arc major problems limiting shelf life of early-season seedless grapes grown in the Sonoran Desert. This research was conducted to assess conditions improving cluster performance in cold storage (4C±1,. 90% R.H.). Clusters were packed: 1) loose, 2) wrapped in perforated plastic bags, 3) loose and water supplement added, and 4) in plastic bags + water supplement. After 12 days in storage, weight losses accounted for 7.0, 5.6, 8.5, and 4.0% of initial fresh weight for treatments in ascending order. In another experiment, individual clusters were stored in modified atmospheres using a high gas-permeability film with two different gas-exchange areas of 25 and 75 mm2. Cluster weight and gas composition significantly interacted with storage period. During the first 30 days, weight loss was not higher than 0.5% on every sampling date. Gas composition was affected by the effective exchange area After 47 days, CO2 concentration was 2.22% and 0.8% in the 25 and 75mm2 treatments. At any given time, oxygen content followed the opposite trend with final values of 18.9 and 20.0% for the same treatments. Although cluster quality was highly preserved, eventually rots developed.
811 PB 196 FOLIAR VARIATIONS IN FALL COLOR DEVELOPMENT AMONG FIVE PLANT SPECIES
Authors: Singha Suman , Bible Bernard , Corbett Edward
Published: February 2019

Variations in the pattern of fall color development in the leaves of Acer rubrum, Acer saccharum, Quercus coccinea, Oxydendrum arboreum and Euonymus alatus were determined. CIELAB coordinates were measured with a Minolta CR-2000b calorimeter at a marked location on 5 tagged leaves from 2 plants of each species. The changes in hue follow similar trends in these species, but the time of onset varies. Onset of red color development increased variability in hue between leaves of the same species. Based on color changes in E. alatus anthocyanin development occurs prior to significant loss of chlorophyll and red coloration remains masked, whereas in A. rubrum anthocyanin development occurs in association with or following the loss of chlorophyll. This results in differences in the pattern of hue and chroma development between these species.
812 PB 199 FORMULATION OF WILDFLOWER MIKES FOR SITE SPECIFICITY
Authors: Corley W. L.
Published: February 2019

Contrary to popular notion, many wildflower taxa are quite specific in their edaphic requirements. From a compilation of 35 species adapted to Georgia and the Southeastern U.S., several mixes have been formulated to meet the siting preference of these taxa whose persistence may be annual, biennial, or perennial. Mixes presented are suited for landscape color, partial shade, xeric, mesic, aggressive, and specialty uses.
818 PB 237 USE OF BIOSOLIDS FOR SOD PRODUCTION
Authors: Benmbarek Mouna , Desiardins Y. , Simard R.R.
Published: February 2019

Landfiling and incineration constitute the most commonly used methods of biosolid disposal. To minimize the environmental risk, their chemical and biological characteristics have been the subject of several investigations.

The present research was undertaken to evaluate the agronomic value of municipal solid wastes (MSW) and composted de-inked sludge (CDS) in a field experiment for sod production. Four variables in a split factorial design, were investigated at two sod farms: compost (MSW and CDS), soil (sandy loam and clay loam), application method (surface applied 6cm and incorporated 20cm), and the application rate (50-100 and 150t/ha). Controls consisted of unfertilized and unamended but fertilized plots. Both experimental sites were seeded with kentucky bluegrass.

Preliminary data indicate that the two biosolids promoted the sod growth at the rates applied. However, a better plot cover was observed if composts were rototilled at a depth of 6cm as compared to the conventional treated plots. Measurements of root and foliar weights revealed that the turf growth was enhanced with increasing rates, which is probably caused by additional soil macronutrients showed by the analysis. Seed germination and seedling emergence were not delayed as indicated by the observed increase in the water retention capacity of the soil especially at higher compost rates.
819 PB 240 PERFORMANCE OF EVERGREEN AZALEAS AS AFFECTED BY SOIL AMENDMENTS AND LANDSCAPE EXPOSURE
Authors: Pair John C.
Published: February 2019

Since 1974, numerous species and cultivars of evergreen azaleas have been evaluated for hardiness and adaptability to south central Kansas (zone 6). Selections included Kurumes, Gable hybrids, Shammarello hybrids and others in various amended beds and in several landscape exposures. Hardiest cultivars include `Boudoir', `Caroline Gable', `Herbert', `Karens', `Pride's Pink', `Purple Splendor', and `Snowball' which flowered following -18F (-28C). Moderately hardy were `Elsie Lee', `Holland', `Girard Roberta' and `James Gable'. Best hardiness was found in cultivars and hybrids with Rhododendron kaempferi, and R. yedoense var. poukhanense parentage. Plants in soil amended with sphagnum peat moss or peat plus sulfur were superior to those in soil containing cotton burrs. Winter shade proved valuable in providing the best landscape site and northeast was generally better than a northwest exposure.
827 PB 304 ESTIMATING TURFGRASS EVAPOTRANSPIRATION USING ATMOMETERS AND EMPIRICAL MODELS
Authors: Fry Jack D. , Wiest Steven C. , Upham Ward S.
Published: February 2019

Evapotranspiration from tall fescue, perennial ryegrass and zoysiagrass turfs during the summers of 1992-3 was compared to evapotranspiration estimates from an evaporation pan, a black Bellani plate, and several empirical combination models, Actual measurement of turf water use was made with small weighing lysimeters. Soil was maintained at field capacity. Data were collected on 51 dates between June and September. Tall fescue was clipped weekly at 7.6 cm whereas ryegrass and zoysiagrass were clipped 3 times weekly at 2.5 cm, Although differences between the grass species existed, in general the rankings of estimate precision were Bellani plate > evaporation pan > empirical models when compared with measured evapotranspiration rates.
828 PB 308 IMPROVED WATER USE EFFICIENCY WITH MODIFIED CONTAINERS
Authors: Fare D.C. , Gilliam C.H. , Keever G.J.
Published: February 2019

Improved water use efficiency exists for plants grown in modified containers to minimize leaching and reduce irrigation frequency which subsequently reduces NO3-N leachate. Salvia splendens `Bonfire' and Impatiens wallerana `Pink' (super elfin hybrid) were potted in ProMix BX medium (Premier Brands, Inc., Stamford, CT) into nine container styles with modified drainage holes to determine leachate volume and quantify NO3-N leached. Three styles had four drainage holes on the container side with hole diameters of 0.5, 1.0, and 1.9 cm, respectively; three styles had four drainage holes on the container side and one drainage hole in the bottom center with hole diameters of 0.5, 1.0, and 1.9 cm, respectively; and three styles had one drainage hole in the bottom center with hole diameters of 0.5, 1.6, and 1.9 cm, respectively. Plants were hand watered when an individual container's medium reached 80% of container capacity. Leachate volume, irrigation frequency, and leachate NO3-N was reduced as drainage size hole decreased in size and number. Plant quality was similar among container modifications.
836 PB 352 EFFECTS OF PRIMING ON MUSKMELON SEED STORABILITY
Authors: Oluoch Melkizedek O. , Welbaum Gregory E.
Published: February 2019

Priming (controlled hydration followed by drying) has been shown to decrease seed storage life in some species The germinablity of primed (0.3 M KNO3, 6 d, 25°C) and unprimed muskmelon (Cucumis melo L., cv. PMR 45) seeds were compared after storage for 9 yrs at less than 20°C and 6% moisture content (MC) (dwt basis). Germination performance was compared at 30°C in water and polyethylene glycol solutions of -0.2, -0.4, -0.6, -0.8, and -1.0 MPa water potential or in water at 15, 20, and 25°C. Seeds were also germinated in field soils at 17, 19, and 21% (dwt. basis) MC in a greenhouse, Some seeds were subjected to controlled deterioration at 20% MC and 45°C for 72 hrs prior to testing. The germination percentage and rate of stored, primed seeds at 30°C and all water potentials was less than stored, unprimed seeds. At 30°C, stored, unprimed seeds germinated more rapidly and to higher percentages at -0.2 MPa than in water, while germination percentages and rates of stored, primed seeds were essentially the same. At 15, 24, and 25°C, stored, primed seeds outperformed unprimed seeds in all germination tests. In saturated soils at 21% MC, there was no germination of either stored, primed or unprimed seed. At 17% soil MC, stored, primed seeds germinated 73% compared to only 56% for unprimed seeds. The enhancement due to priming was retained after 9 yrs of storage at germination temperatures <30°C. At higher temperatures, the germination of unprimed seeds was superior to primed.
843 PB 485 EFFECT OF SUCROSE SOLUTIONS ON POSTHARVEST LIFE OF SATIN FLOWER (Clarkia arnoena)
Authors: Anderson Robert G.
Published: February 2019

Greenhouse grown cut stems of satin flower were used in a series of postharvest experiments to determine the effect of sucrose on flower life, flower quality and the overall vaselife. Experiments in 1993 compared 0, 0.5, 1.0 and 2.0% sucrose in tap water with and without a biocide (4 ppm sodium hypochlorite). Cut stems of `Grace Rose Pink,' `Grace Salmon and `Grace Red' were harvested, stored in a refrigerator overnight at l-2” C.; all cut stems were maintained in randomized individual vases in a room kept at 22-23 C with fluorescent lighting (50 ft.c.) from 0800-2000 HR. Postharvest performance was best in tap water, tap water + biocide, and 0.5% sucrose + biocide with excellent flower opening and flower quality for 10-14 days. Leaf yellowing and leaf necrosis increased greatly with the increasing concentrations of sucrose. Flowers of `Grace Salmon' showed significant petal necrosis in the treatments with higher concentrations of sucrose.
852 PB 399 POTENTLAL USE OF OXADIAZON AND SETHOXYDIM FOR THE PRODUCTION OF FOUR WOODY ORNAMENTAL PLANTS GROWN IN CONTAINERS
Authors: Iraqi Driss , Duchesne Isabelle , Rioux Jacques André
Published: February 2019

The objective of this study is to determine the phytotoxicity and efficiency of oxadiazon and sethoxydim used as herbicide in the production of four species of woody ornamental plants grown in containers. Four species were used: Cornus alba `Argenteo Marginata', Weigela florida `Rumba', Prunus x cistena and Thuja occidentalis `Woodwardii'. Six herbicide treatments were used (oxadiazon at 0,4 and 8 Kg (a.i.)/ha; sethoxydim at 0.000, 0.276 and 0.552 Kg (a.i.)/ha) and two controls were added (weeding and unweeding). The eight treatments were included in a complete block design replicated six times. This project was started in July 1993 and was conducted for three months. If phytotoxic symptoms were present on plants they were recorded and their effects on growth was measured. At the end of the experiment, weeds present in pots were identified, counted and their growth measured. Preliminary results showed that oxadiazon applied at rates of 4 and 8 Kg (a.i.)/ha had a good efficiency weed control in container production. Sethoxydim applied at rates of 0.276 and 0.552 Kg (a.i.)/ha had a good grass control. The two herbicides did not show phytotoxic symptoms on the for species used. The effects of herbicides on plant growth will be presented.
866 PB 545 PRODUCTION POTENTIAL OF ESSENTIAL OIL CROPS IN SAUDI ARABIA
Authors: Sarwar Mohammed , Al-Namlah Saleh A.
Published: February 2019

Saudi Arabia is known for arid character and its total unsuitability for any agricultural exploitation. However; it is- now proving otherwise with the application of modern agrotechnology resulting in large scale production of many crops successfully. Considering the international growing demand of essential oils, need of agrocommunities for new crops, advantages of local warm climate and availability of generous government funding system, essential oil production offers immense potential in Saudi Arabia. This paper intends to describe the prospects of raising Pelargonium graveolens, Mentha arvensis, Artemesia pallens, Cymbopogon winterianus, Cymbopogon flexuosus, Ocimum basilicum, Eucalyptus citriodora, Rosemarinus officinalis, Coriandrum sativum, Anethum graveolens, Jasminum grandiflorum and Pogostemon patchouli successfully at various ecosystems and to establish new agroindustries based on essential oils around the Kingdom.
863 PB 547 IMPROVING SEED GERMINATION OF ANGELICA (Angelica archangelica L.)
Authors: Laflamme Lucette , Tremblay Nicolas , Michaud Marie-Hélène
Published: February 2019

Angelica is grown in Quebec (Canada) for its root-bound medicinal properties. Matol Botanique Int., a major user of Angelica extracts, decided 4 years ago to promote local production in order to secure supplies and quality. However, the crop has to be started from seed that show low and variable germination behavior. Emergence occurs after ± 12 days and most of the germination if obtained after 20 to 40 days depending on seed origin and test conditions. Maximum germination ranges from 6 to 57%. Three treatments were first compared in order to stimulate germination: seed soaking in warm water for 24 h, watering germination trays with algae extracts and placing floating row covers over the trays. Angelica germination was significantly improved only by row covers with a maximum of 24% vs 19%. Results were obtained from experiments with other techniques (stratification, seed conditioning, etc,...) to further improve germination.

2Working for the Horticultural Research Centre, Laval University, Que.
886 PB 460 SOMATIC EMBRYOGENESIS FROM IMMATURE COTYLEDONS OF TEXAS BLUEBONNET
Authors: Sankhla Daksha , Davis Tim D. , Sankhla N.
Published: February 2019

This study was initiated to test the embryogenic potential of immature cotyledons (3-5 mm long) of Texas bluebonnet (Lupinus texensis). The embryo initiation medium consisted of B5 salts and vitamins with 3% sucrose and 22.6 μM 2,4-D alone or in combination with 1-15 μM of various cytokinins. Within 15-20 days, globular embryos were formed on the distal end of the cotyledons. Eventually the entire cotyledon surface was covered by embryo-like structures. Addition of cytokinins to the medium did not increase the percentage of cultures which formed embryos. In fact, addition of thidiazuron severely inhibited embryogenesis. Following transfer to an embryo maturation medium (MS medium with 0.38 μM abscisic acid alone or in combination with benzyladenine or zeatin) for 10-14 days, the embryos were placed in MS medium supplemented with GA (2.9 μM) or glutamine (200 mg/liter) with or without activated charcoal (0.5%) for embryo germination and plantlet development. Most of the embryos exhibited precocious germination and well-developed roots but failed to produce normal shoots. Therefore, additional work is needed to improve embryo conversion frequency.
930 PB 536 FORCING METHOD AND ROOTSTOCK AFFECT SCION BUDBREAK AND GROWTH OF CITRUS NURSERY TREES
Authors: Williamson J.G. , Maust B.E.
Published: February 2019

Two experiments were conducted to determine the effects of bud forcing method and rootstock on scion budbreak and nursery tree growth of `Han-din' orange (Citrus sinensis Osb.) In Expt. 1, Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.] (Ca), Swingle citrumelo [C. paradisi (L.) Osb. × P. trifoliata (L.) Raf.] (Sw), and Cleopatra mandarin (C. reticulata Blanco) (Cl) were budded with `Hamlin' orange and forced by cutting off the rootstock tops, lopping (cutting half way through the rootstock stem above the scion bud), or bending the rootstock top and tying it to the trunk). For Cl and Ca percent budbreak was high for all forcing methods. For Sw percent budbreak was greater for cutting off than for lopping or bending. For Sw and Ca, bending or lopping resulted in greater whole plant and scion dry weights than cutting off. Expt. 2 was similar to Expt. 1 except that bending was used alone, or in combination with notching (cutting an invertal v-shaped notch above the scion bud), or with topping the bent rootstock shoot. Scion budbreak of Sw plants was greater for bending + notching than for bending alone. Other effects of rootstock and forcing method for cutting off, bending or lopping were similar to those found in Expt. 1.
920 PB 461 CONTROLLED ATMOSPHERE AFFECT STORAGE QUALITY OF ZUCCHINI SQUASH SLICES
Authors: Izumi Hidemi , Watada Alley E.
Published: February 2019

Physiology and quality of CaCl2 treated or nontreated `Elite' zucchini squash slices were monitored during storage in air, low O2 (0.25, 0.5 and 1%) or high CO2 (3, 6, and 10%) atmosphere at 10C. O2 consumption and CO2 production were reduced under low O2 and high CO2 atmospheres and the reduction was greater with low O2. C2H4 production was reduced with low O2 and initially with high CO2. After day 2 or 4, C2H4 production under high CO2 increased with the increase being greater at the lower CO2 level. The amount and severity of injury/decay were less under low O2 and high CO2 than air atmosphere. Slices stored under 0.25% O2 atmosphere had less weight loss and injury/decay and greater shear force and ascorbic acid content than those held in air atmosphere. Microbial count, pH, and color were affected by the low O2 only on the last day. CaCl2 had no additive effect.
921 PB 464 EFFECTS OF STORAGE TEMPERATURE AND RELATIVE HUMIDITY ON THE QUALITY OF EIGHT SQUASH VARIETIES
Authors: Feibert Erik B. G. , Shock Clint C
Published: February 2019

Eight winter squash varieties (Table Ace Acorn, Sweet Dumpling, Waltham Butternut, Honey Boat, Sugar Loaf, Spaghetti, Gold Keeper, and Kabocha) were placed in storage 3 weeks after harvested and were stored for 6, 12, or 16 weeks at 5, 10, or 15°C and 50, 60, or 70 percent relative humidity. Before storage Spaghetti squash had low dry weight and low sugars while Kabocha, Sugar Loaf, and Honey Boat had high dry weight and high sugars. Squash of all varieties suffered high spoilage when stored at 5°C. Water losses increased with temperature or with storage at 50 percent relative humidity. Considering both spoilage and water loss, marketable fruit was highest when squash was stored at 10°C or 15°C and 60 or 70 percent relative humidity. Squash sugars were maintained with storage at 5°C and 10%. Squash can be stored for several months at 10°C and 60 to 70 percent relative humidity with little fruit loss or loss of sugar.
930 PB 509 CHANGES IN CUTICLE CHARACTERISTICS DURING POSTHARVEST HANDLING OF BELL PEPPERS
Authors: Báez-Sañudo R. , Bringas E. , Mercado J. , Báez M. , Siller J. , Gardea A.
Published: February 2019

Dehydration limits bell pepper postharvest life. Research had focused on waxes and individual sealed packages used to prolong shelf-life. Even though, the fruit natural package -the cuticle- is unknown; besides, cuticle functions as a barrier to protect fruits against excessive water loss. The objective of this work was to characterize cuticle changes and their relationships with fruit quality during postharvest handling. Green `Wonder' bell peppers were stored under marketing conditions (20C; 65-70% RH). Following cuticle isolation determinations included weight changes (CW), permeability and soluble cuticular lipids (SCL). In addition, quality characteristics like firmness, total soluble solids (TSS), titratable acidity (TA) and CO2 production were monitored every other day. CW and SCL decreased from 2798 to 1398 and 145 to 48 μg/cm2, respectively. Permeability was also reduced from 11 to 10 mg/cm2*h. CO2 climateric was reached between the 9 and 12th day peaking with 25 mg/kg*h. Firmness decreased from 2.1 to 1.1 Kg*f, while no noticeable changes were observed on TSS and TA.
940 IN VITRO SYSTEMS FOR ENHANCED PRODUCTION OF VALUABLE PHYTOCHEMICALS IN BEGONIA SP.
Authors: George N.J. , Madhavi D.L. , Smith M.A.L.
Published: February 2019

Many plants can produce bioactive chemicals with medicinal or health benefits, which has stimulated a whole new research effort aimed at extracting & improving natural phytochemicals. Begonia is a rich source of biologically-active phytochemicals and an excellent donor for natural anthocyanin pigments. High levels of triterpene compounds and a host of potentially-useful flavonoids have been isolated from Begonia sp., which may account for its frequent use as a medicinal plant remedy in a diverse array of cultures worldwide. Deliberate shifting of the physical and chemical microenvironments can have a significant effect on anthocyanins and precursors produced in vitro. This realization offers the potential to thoroughly screen and study valuable phytochemicals from Begonia. Begonia genotypes from 3 species were screened to identify callus induction techniques. Contamination inherent in the vascular system of one genotype, along with spontaneous organogenesis, were found to be recurrent problems. These were partially alleviated by light and growth regulator treatments. Studies comparing callus and in vitro vegetative tissues as resources for phytochemical extraction are scheduled.
956 PB 479 A WILDLIFE HABITAT IN THE SOUTH CAROLINA BOTANICALGARDEN
Authors: Wilson Stephen , Hague Mary
Published: February 2019

America's rejuvenated interest in environmentalism provides landscape designers an excellent opportunity to integrate natural wildlife habitats within the landscape. Due to urbanization and rapid development, niches for many animals are being destroyed. Too often we rely on our state and national parks to replace what is lost, when we really should begin In our own backyards. In conjunction with the South Carolina Wildlife Federation, the South Carolina State Botanical Garden has initiated a program that will create a Backyard Wildlife Habitat. The purpose of my project is to create a garden with ornamental and native flora to attract local fauna, while educating botanical garden visitors to concepts that they can apply In their own back yards, neighborhoods, schools. and communities.

My presentation will outline the goals, methodology, and results of the project. In addition, I will discuss the concepts that make a site a Backyard Wildlife Habitat.
990 RECENT ADVANCES IN PLANT RESPONSE TO MECHANICAL STRESS: THEORY AND APPLICATION
Authors: Mitchel Cary A.
Published: February 2019

Brief, periodic seismic (shaking) or thigmic (contact rubbing) stress treatments applied to plants growing in a wind-protected environment typically reduce but strengthen vegetative growth and often inhibit reproductive development. Cell division and cell enlargement both are affected. Mechanically dwarfed plants accumulate less leaf area than do undisturbed controls and undergo temporary stomatal aperture reduction following an episode of stress, leading to reduced photosynthetic productivity. Vibration or mild shaking may lead to a slight stimulation of plant growth. Most classes of phytohormones have been implicated to mediate different growth responses to mechanical stress. Physical perturbation turns on the transcription of several genes coding for calmodulin-like proteins. Calcium chelators and calmodulin inhibitors partially negate effects of thigmic stress. Growth rate responses of naive seedlings are immediate and dramatic, suggesting turgor collapse, whereas recoveries are slow and sometimes partial, suggesting reduced wall extensibility in the cell enlargement zone. Mechanical stress may be used for height control of intensively cultivated bench crops or to physically toughen bedding plants prior to outdoor transplant. Physiological hardening remains a question. Mechanical height control avoids use of chemicals but increases risk of wounding and pathogen infection.
1002 ADAPTATION OF BEAN SEEDLINGS TO LOW P AVAILABILITY
Authors: Lynch Jonathan
Published: February 2019

Low P availability is a primary limitation to plant growth on most native soils. Crop genotypes differ substantially in their ability to grow in low P soils. Understanding the physiological basis for such variation would be useful in developing genotypes with superior P efficiency, which would have utility in low-input systems and might permit more. efficient fertilizer use in high-input systems. In common bean (Phasecolus vulgaris), growth under P stress is reduced because of increased C costs of the root system. Genetic contrasts in P efficiency were not associated with reduced shoot requirement, mycorrhizal associations, chemical interactions with specific soil P pools, or root system size, but were associated with root system architecture. SimRoot, an explicit geometric model of bean root growth, confirmed that architectural traits can influence the relationship of root C costs and P acquisition. Root growth responds dynamically to P stress, through changes in the proliferation of lateral roots and the geotropic response of basal roots. Differences in root architecture arising from these growth responses to P stress may account for genetic differences in P efficiency.
1022 THE EFFECT OF NITROGEN STATUS ON PRODUCTIVITY AND RECOVERY OF ISOTOPICALLY LABELLED FERTILIZER N BY MATURE ALMOND TREES
Authors: Weinbaum Steven A. , Asai Wesley , Goldhamer David , Niederholzer Franz J.A.
Published: February 2019

A project to study the interrelationships between leaf N conc., relative tree yield (RTY), nitrate leaching and fertilizer N recovery was established in 1990. Collection of pretreatment baseline data was followed by differential rates of N fertilization. Significant differences in leaf N conc. and RTY were obtained in 1992 and 1993, respectively. RTY is defined as tree yield in 1993 expressed as a percentage of pretreatment (1990) yield. 15N-depleted (NH4)2SO4 was applied postharvest in 1993 to 17 trees differing in RTY and leaf N conc., and recovery of labelled N in the blossoms of these trees (March, 1994) will be discussed.
1029 PREDICTING IN-SEASON NITROGEN REQUIREMENTS FOR IRRIGATED POTATOES USING NITRATE SAPTESTS
Authors: Rosen Carl J. , Errebhi Mohamed
Published: February 2019

Applying appropriate rates of nitrogen fertilizer during the growing season for potatoes on irrigated sandy soils is an important concern from both a production and environmental standpoint. Although potatoes on sandy soils are responsive to nitrogen fertilizer, high rates of nitrogen applied early in the growing season have been associated with nitrate leaching due to unpredictable rainfall. Use of lower nitrogen rates applied more frequently through the season is one strategy to minimize nitrate losses and improve nitrogen use efficiency. Portable nitrate electrodes were used to measure nitrate concentrations in petiole sap. Diagnostic criteria based on final yield and nitrate sap concentrations at various growth stages were developed over a three year period. This rapid test can now be used to make an immediate assessment of nitrogen status of the plant and a prediction for whether supplemental nitrogen will be needed. On-farm trials are currently being carried out to demonstrate the use of the saptest as a best management practice.
1042 UNDERSTANDING SEED VIGOR
Authors: Sayers R.L.
Published: February 2019

Seed vigor is an important consideration today for seed companies as well as seed consumers. Effective use of seed vigor is, however, significantly hampered due to a lack of understanding and education on the subject. Benefits and limitations of seed vigor information will be addressed as they relate to seed companies, regulatory agencies and the seed consumer.
1048 HEAT AND MODIFIED ATMOSPHERES FOR CONTROL OF POSTHARVEST DECAY
Authors: Mitcham Elizabeth J.
Published: February 2019

The produce industry faces a future with reduced access to postharvest fungicides. It has become increasingly important to reduce commodity susceptibility to decay and to develop non chemical methods for decay control. Heat therapy has been demonstrated to be effective for control of numerous decays and is currently practiced for control of anthracnose in mangoes and papayas and for decay control in oranges. The limitations to heat therapy include the often tine line between effectiveness and commodity injury and the lack of residual protection. Modified atmosphere has been used effectively for many years by the California strawberry and raspberry industry to allow cross-country shipment of a commodity on which no postharvest fungicides are used. It has been shown that CO2 concentrations of 15% and higher inhibit the growth of many fungi, including Botrytis cinerea, the main cause of strawberry decay. Many commodities cannot tolerate 15% CO2 for an extended period of time. However, the short term (1 to 3 weeks) tolerance has not been determined. With the loss of postharvest fungicides, we may find that many commodities could benefit from shipment under high CO2, as have strawberries. The combination of heat therapy and MA will also be discussed.
1059 SPRAY APPLICATION TECHNIQUES
Authors: Unrath C.R.
Published: February 2019

The canopy of an apple orchard can be objectively quantified by using tree height and cross row limb spread to calculate the tree row volume (TRV). Use of the appropriate water rate, adjusted for canopy density, is an effective tool for determining full dilute water rate for airblast applications. To save run off most dilute pesticides are applied at 70% of TRV. TRV model use will be discussed and illustrated. Comparison of handgun vs airblast applications showed more deposition and thinner activity w/handgun. Thinners applied at a fixed concentration of a.i. showed decreased activity as volume decreased. Applications at the same a.i./ha, regardless of water volume showed similar activity at and below TRV water and reduced activity at higher than TRV water, indicating activity loss from run off. Added testing showed uniform thinner activity only if water volume was within ± 20% of tree TRV rate. A fruit dip experiment showed greatly differing natural fruit drop but similar added chemical induced fruit drop between top, lower outside and lower inside of apple trees, a factor which must be adjusted for w/nozzle distribution on large trees.
1062 SAMPLING CONSIDERATIONS FOR CHEMICAL THINNING TRIALS
Authors: Marini Richard P.
Published: February 2019

Counting blossoms before treatment and collecting yield data for whole trees following thinning treatments arc expensive practices. Researchers often collect data on sample branches to reduce the time and expense of data collection. How accurate are these techniques? To generate discussion concerning sampling, results will he presented for several experiments where data were collected for whole trees vs. sample branches. Data will also be presented for different ways of assessing fruit size at thinning time. Fruit diameter, fruit weight and fruit volume were recorded for several cultivars over several seasons. I hope to generate discussion about the desirability of these different measures of fruit development.
Water Relations of Leaves of `Sonia' Rose Plants Grown in Soilless Greenhouse Conditions
Authors: Urban L. , Brun R. , Pyrrha P.
Published: February 2019

Rose plants (Rosa hybrids cv. Sonia) were grown in rockwool in two heated greenhouses: one with relative humidity (RH) control (RH >70%) provided by high-pressure mist, the other protected against overheating using a movable screen without RH control. Two electrical conductivity (EC) rates were applied: high (EC of drainage water ≈ 3.8 mS·cm-1) and low (EC of drainage water ≈1.8 mS·cm-1). Under these conditions, water deficit in plants was due mainly to climate, and not to EC. The relative water content of sample leaves picked at noon (RWCnoon) was one to two percentage points higher in the greenhouse with RH control and dropped by 6% to 7% in summer. RWCnoon was unaffected by differences in EC. The average elastic modulus (E) and the relative water content threshold for turgor loss (RWC0) were reduced in the greenhouse with RH control. ϵ was increased in the high EC treatment, but RWC0 remained unaffected.
Early Leaf Harvest Reduces Yield but Not Protein Concentration of Cowpea Seeds
Authors: Nielsen S.S. , Osuala C.I. , Brandt W.E.
Published: February 2019

Five greenhouse-grown cowpea [Vigna unguiculata (L.) Walp] cultivars were tested in a generalized random complete-block design to determine the effect of early leaf harvest on dry weight and protein concentration of plant parts at maturity. The most recent, fully expanded leaves on each branch from one group of plants were harvested at 5 and 7 weeks after planting. On the other groups of plants, no early leaf harvest was performed. Dry weight and protein concentration (dry weight basis) were determined for leaves, stems, and seeds at maturity and for leaves harvested early. Weight and protein concentration of seeds, leaves, and stems differed significantly between cultivars; protein concentration of leaves harvested at 5 or 7 weeks did not. Dry weight of leaves harvested at 5 vs. 7 weeks did not differ significantly, but leaf protein concentration was significantly higher at 5 weeks compared to 7 weeks. Across all cultivars, early leaf harvest had no significant effect on leaf or stem weight per plant at maturity. However, there was a significant decrease in seed weight when leaves were harvested early. Results suggest that even limited leaf harvest at 5 and 7 weeks has detrimental effects on yield, but not on protein concentration, of cowpea seeds harvested at maturity.
Threshing Cylinder Speed Affects Germination of Amaranths cruentus L. Seeds
Authors: Krishnan Palaniappa , Evans Thomas A. , Pill Wallace G.
Published: February 2019

The percentage of normal grain amaranth seedlings decreased and that of abnormal seedlings increased as threshing cylinder speed increased from 8.1 to 30.7 m·s-1. At the highest threshing speed, seed deterioration (loss of germination and increase in the percentage of abnormal seedlings) was exacerbated by increasing seed storage from 7 to 47 months. Threshing cylinder speeds of 8.1 to 12.8 m·s-1 resulted in similar percentages of normal seedlings as those achieved with hand-harvesting and threshing. Although injury to hand-harvested seeds or seeds threshed at 8.1 m·s-1 was not apparent, scanning electron micrographs of seeds threshed at 12.8 or 22.4 m·s-1 revealed damage to the seedcoat and the endosperm. Damage extended to the embryo when threshing cylinder speed was increased to 30.7 m·s-1.
Biological Control of Annual Bluegrass with Xanthomonas campestris pv. poannua in Bermudagrass
Authors: Johnson B. Jack
Published: February 2019

Xanthomonas campestris pv. poannua has potential as a biological control agent for perennial ryegrass (Lolium perenne L.), and it is being evaluated as a commercial bioherbicide. Field experiments were conducted on dormant `Tifway' bermudagrass [Cynodon transvaalensis Burtt-Davy × C. dactylon (L.) Pers.] and `Tifway' bermudagrass overseeded with perennial ryegrass to determine the effects of two isolates of X. campestris pv. poannua on annual bluegrass (Poa annua L.) control. Annual bluegrass control was 82% on 27 Apr. 1992 after isolate MB 218 was applied to dormant bermudagrass at 109 cfu/ml in three applications on 11 and 28 Feb. and 12 Mar. When isolate MB 245 was applied at the same rate and dates, it controlled only 60% of the annual bluegrass. The response from isolate MB 245 at the same rate and number of applications on 28 Apr. 1993 was similar to that in Apr. 1992, with 64% control on dormant turf and 52% control on overseeded turf. There was no significant advantage in annual bluegrass control when isolate MB 245 was applied at 109 cfu/ml in more than three applications during the fall and winter, compared to three applications on 15 Feb. and 1 and 11 Mar. when ratings were made on 28 Apr. 1993. The control of annual bluegrass in late Apr. 1992 and 1993 from X. campestris applied in three applications (11 and 28 Feb. and 12 Mar. 1992 and 15 Feb. and 1 and 11 Mar. 1993) at 109 cfu/ml was greater than when l08 cfu/ml was applied on the same dates.
Early Harvest and Oven Drying Temperatures Influence Pecan Kernel Flavor
Authors: Herrera Esteban A.
Published: February 2019

`Western Schley' pecans [Carya illinoinensis (Wangenh.) K. Koch] were evaluated for flavor by a 17-person sensory panel after oven-drying nuts that had been harvested 1 to 7 weeks before normal harvest in 1985. The nuts were 1) not dried, 2) oven-dried 24 hours at 29C, 3) oven-dried 24 hours at 35C, 4) oven-dried 30 hours at 29C, 5) oven-dried 30 hours at 35C, 6) dried at room temperature for 72 hours, and 7) collected at normal harvest time (control). At the start of the experiment, kernel moisture was ≈ 14%. Some of the treatments reduced kernel moisture to <5 % the first week of the experiment, but drying nuts at room temperature for 72 hours reduced kernel moisture as effectively as other treatments. Judging by kernel flavor, pecans can be harvested ≈ 4 weeks before normal harvest (performed after the first freeze in Las Cruces, N.M.) and artificially dried without affecting flavor.
In Vitro Propagation of Eriostemon myoporoides and Eriostemon `Stardust'
Authors: Ault James R.
Published: February 2019

Optimal axillary shoot proliferation was obtained from stem explants of a clone of Eriostemon myoporoides DC. on Murashige and Skoog (MS) basal medium containing 0.1 mg BA/liter, and of Eriostemon `Stardust' on MS medium containing 0.5 mg BA/liter. Overall average number of shoots and shoot lengths for all treatments was greater for E. `Stardust' (22.4 shoots and 12.1-mm shoot length) than for E. myoporoides (4.5 shoots and 8.3-mm shoot length). Maximum percent rooting of E. myoporoides (42%) and E. `Stardust' (95%) was obtained on MS medium supplemented with 1.0 mg K-IBA/liter for E. myoporoides and 0.1 mg NAA/liter for E. `Stardust'. Overall average percent rooting and root lengths were greater for E. `Stardust' (42% rooting and 11.0-mm root length) than for E. myoporoides (27% rooting and 2.3-mm root length). For E. `Stardust', reducing sucrose in the rooting medium from 50 to 25 g·liter-1 significantly decreased overall average percent rooting to 1670 and root length to 6.8 mm. Plantlets of both clones were acclimatized in the greenhouse and transferred successfully to soil, although survival was <7070. Chemical names used: N -(phenylmethyl) -l H -purine-6-amine (BA); potassium-l H -indole-3-butyric acid (K-IBA); l-naphthaleneacetic acid (NAA).
NITROGEN FERTILIZATION OF SWEET POTATO AND ITS EFFECT ON HOOT SET AND YIELD
Authors: Mulkey W.A. , McLemore W.B. , Talbot T.P.
Published: February 2019

In preplant nitrogen studies with the `Beauregard' Variety maximum yields of U.S. No. 1 grade roots are produced using 50.4 kg/ha N. In 1992 studies were initiated to determine the effect of preplant N rates on storage root set and yield. Preplant N rates ranged from 0 to 84 kg/ha in 16.8 kg/ha increments. Two plots each of 0, 16.8 and 33.6 kg/ha were included so sidedress applications could be made to bring one of the treatments to the 50.4 kg/ha N level 30 days after transplanting. The 0 kg/ha N treatment had significantly more storage roots per plant than all other treatments 21 days after transplanting and more vine growth measured by weight. The 0 and 16.8 kg/ha treatments had significantly more storage roots 26 days after transplanting. At 26 and 35 days after transplanting vine growth was greater in 16.8 kg/ha N treatment. The 0 plus 50.4 kg/ha N sidedress treatment produced the highest yield of U.S. No. 1 grade roots with the highest number of marketable roots per plant (5.0). Similar results were obtained in the 1993 studies.
THE EFFECT OF FLOWER REMOVAL ON THE YIELD OF EARLY AND LATE MATURING SWEETPOTATO (IPOMOEA BATATAS L.) CULTIVARS
Authors: Khan V. A. , Stevens C. , Lu J. Y. , Wilson M. A. , Brown J. E. , Rhoden E. G. , Mafolo T. , Kabwe M. K.
Published: February 2019

TU-155 and Georgia-Jet early, TU-1892 and Carver late maturing sweet-potato cultivars. were evaluated in the field to determine the effect of flower removal (FR) would have on marketable storage, root numbers and yield. Other parameters measured were leaf area and numbers, plant fresh and dry weight. Plants were sampled at 57 and 71 days after transplanting (DAT). All flowers were hand removed and the 1st harvest began 45 days DAT for the early and at 60 DAT for the late maturing cultivars. All flower harvests concluded 22 days after 1st harvest began and roots were harvested 120 DAT. There was significant differences among cultivars for total flower production with N-1892 and Georgia-Jet having the highest flower production. FR treatments for N-155 and Georgia-Jet showed significant increases for plant dry weight, leaf area and numbers 71 DAT while Carver and TU-1892 showed no significant differences for the same sample period. Marketable root numbers were not significantly affected by FR but marketable yields for all cultivars were. Overall, the cultivars showed variation both within and among maturity groups in their response to FR treatments, for example N-155 had a 39% compared to 3% increase for Georgia-let while Carver had a 15% increase in marketable yield compared to 5% for TU-1891.
ALTERING NUTRIENT SOLUTION N:K RATIO TO INCREASE YIELDS OF SWEETPOTATO GROWN IN NFT
Authors: Mortley D.G. , Loretan P A. , Trotman A.A , David P. P , Garner L.C , Carver G. W.
Published: February 2019

The effects of altering, nutrient solution N:K ratio on growth of `TI-155' sweetpotato [Ipomoea batatas (L.) Lam] was evaluated in a greenhouse, as part of NASA's Closed Ecological Life Support Systems (CELSS) program for long duration space missions. Vine cuttings of `TI-155', were grown using nutrient film technique (NFT) in a modified half Hoagland's solution in channels (0.15×0.15×1.2 m). Plants were grown for 42 days in a culture solution in which N was doubled (6 mM) in order to accelerate foliage growth after which treatment N:K ratios of 1:2.4, (control) 1:4.8, and 1:7.2 were initiated. A randomized complete block design with 4 replications was used. The number of storage roots/plant increased linearly as K was increased in the solution. Storage root fresh and dry weights, growth rate (g m-2 d-1), fibrous root dry weight, foliage fresh and dry weights, and edible biomass index (root mass/total plant mass), though not significant all increased as K was increased in the nutrient solution. Nutrient solution analyses showed that K uptake was greatest in plants at the highest K level, while nitrate uptake was steady over the duration of crop growth regardless of treatments.
COMPARATIVE EFFECTS OF SOIL SOLARIZATION AND OTHER AGRIPLASTIC MULCH SYSTEMS ON INCREASED GROWTH RESPONSE AND REDUCTION OF EARLY BLIGHT DISEASE OF FLORADADE TOMATO
Authors: Stevens C. , Khan V. A. , Wilson M.A. , Collins D. J. , Brown J. E. , Lu J. Y.
Published: February 2019

Agriplastic black mulch (BM), row cover (spunbonded) plus black mulch (RBM) and solarized soil treatments plus black mulch (SBM). row cover plus black mulch on solarized soil (RSBM) and row cover plus solar&d soil (RSBS) increased Floradade tomato yield from 56 to 285%. number of tomatoes and plant height compared to the non-solarized bare soil (BS). When comparing increased growth response (IGR) of the plants grown in the solarized soil with no row cover agriplastic treatments, there was no significant differences among them. When comparing the IGR parameters of tomato plants grown under SBS, BM, and RBS there were no significant differences among them. Spunbonded row cover treatments increased IGR of tomatoes over all treatments without row cover. A significant increase in plant growth promoting rhizobacteria (PGPR) was observed in the rhizosphere soil of Floradade tomatoes grown in solarized soil alone and in those other agriplastic treatments compared to bare soil. There appear to be no differences in PGPR population among SBS and all agriplastic treatments.
RICE HULLS AS A SOILLESS MEDIA COMPONENT FOR GREENHOUSE-GROWN PLANTS
Authors: Dueitt Shelly D. , Newman Steven E.
Published: February 2019

Rice hulls, a by-product of rice milling, were used at various rates in greenhouse media. The objective of this study was to determine if rice hulls can replace peat moss. Hulls, aged and fresh, were blended with vermiculite and peat moss from 0 to 50%, by volume replacing peat moss. Physical and chemical properties including bulk density, total pore space, water retention, pH and soluble salt concentrations were determined in the media blends. Marigolds and salvia were transplanted into 13 cm azalea pots containing each media. The bulk density increased with increasing levels of hulls. Total pore space of the media before planting was decreased with increasing levels of aged hulls, but no differences were detected at the termination of the study. Water retention of both fresh and aged hulls at all levels of media were equivalent to the control media. Before planting, the total soluble salts for media containing fresh hulls was greater than with aged hulls. The pH of the media increased with increasing levels of hulls, fresh and aged. The greatest dry weight and plant height was observed when the media contained 10 to 20% aged hulls.