bluuebunny/crossref_metadata_2025 huggingface dataset:
Poinsettia Stem Strength
Authors: Kuehny Jeff S. , Branch Patricia
Published: February 2019

Lateral branches of poinsettia tend to break from the main stem as plants reach maturity. The cause of poor stem strength is not known; however, suggested factors implicated in poor stem strength are: rate of nitrogen fertilizer used, type of plant growth regulator used, crowding of plants, or stem diameter of the cutting. Four different experiments were conducted to determine if these factors affected stem strength of poinsettia. Experiment 1: `Freedom Red', `Success', `V-17 Angelika Red', `Red Sails', `Nutcracker Red', `Cortez', `Maren', and `Red Splendor' poinsettia were fertilized with 20N–1P0–20K at 75, 75/125, 125/200, or 200 ppm N drip fertigation with zero leachate. Experiment 2: Three plant growth regulators were applied to `Pearl' and `Jolly Red' poinsettias. Experiment 3: `Freedom Red' plants were grown in a 625, 900, 1225, or 1600 cm2 area. Experiment 4: Rooted `Freedom Red' cuttings with stem diameters of 4.5, 5.5, 6.5, or 7.5 mm were used. A force meter was used to determine the strength of each lateral on the main stem of the six replications in each experiment. The lower laterals had the least stem strength and the top lateral had the highest stem strength for all treatments in all experiments. The stem strengths of some cultivars in experiment 1 were stronger at the lower fertilizer rates. Type of plant growth regulator had no significant affect on most poinsettia cultivars. The stem strengths of poinsettias in experiments 3 and 4 varied according to which lateral was measured.
Effective Cutting Methods and Media for Hardwood Cuttings in `Sunaga Wase' Peaches
Authors: Lim Kyong Ho , Kim Wol Soo , Lim Hyung Kee , Kim Byeong Sam
Published: February 2019

This experiment was carried out to investigate the effective cutting methods and media for hardwood cuttings in `Sunaga Wase' peach (Prunus persica L.). Using 1-year-old peach stems out of winter pruning, the cutting stems were procurred through several steps on 16 Feb. 1995 and 1996. i) Cut 30 cm in length by pruning scissors and bundled to 10 stems; ii) 1-cm bottom part of cutting stem dipped into IBA (1000 ppm solution) for 5 s and then powdering with Captan WP; iii) upper part of cutting stem coated with Topsin paste; iv) standing the bundled cutting stems in the cutting bench filled with cutting media; v) the temperature maintained at 20 ± 1°C under the level of cutting media by bottom heating and at 5 to 10°C above the media level. Among the cutting media, vermiculite showed the highest rooting percentage, as much as 93.2%, followed by Jiffy pot and rockwool cube. High transplanting survival percentage under field conditions was obtained by the treatment of vermiculite of media + cutting duration for 35 days. Although the treatment of cutting duration for 55 days showed very high percentage of rooting, such as 96.4% in vermiculite, 78.3% in Jiffy pots, and 83.3% of rockwool cube, their percentage of nursery survival after transplanting were reduced remarkably less than 10% in nursery fields covered with black polyethylene film. The nursery trees obtained from each treatment were characteristically 136 to 146 cm in tree height and 22.9 to 26.8 cm in trunk diameter.
Evaluation of the Influence of Packhard on `Ross' Cling Peaches during Postharvest Storage
Authors: Sistrunk Laurence A. , Chapman Dan , Storey J. Benton
Published: February 2019

The Packhard treatment included Packhard® Caenise at 3 qt/A rate applied at four equally spaced intervals beginning on 1 May 1996 and continuing until harvest on 29 July 1996. After harvest, treated and nontreated peaches were stored at 1°C, 95% RH. For up to 42 days, after which they were allowed to ripen for 6 days at 18°C. Fruit from 5-day storage intervals and 2-day ripening intervals were then evaluated for firmness, color, brown rot lesions, soluble solids, titratable acidity, starch, pectin, total Ca, and fruit epidermis thickness. Packhard protected the fruit in cold storage for 42 days from brown rot compared to the controls, which began to breakdown in 26 days. The ripening studies have given mixed results suggesting that there is no difference in the degree of brown rot contamination between Packhard-treated fruit and control fruit after removal from storage. Fruit firmness was increased by Packhard in the majority of the storage periods. Sucrose content seemed to have been reduced in the Packhard-treated fruit compared to the controls, possibly due to increased respiration. The Packhard-treated fruit retained more moisture than the control fruit,, which indicates that Ca2+ from Packhard may have increased the integrity of the plasma membranes of treated fruit. In general, the Packhard-treated fruit held up much better in cold storage than the control fruit but was not different in brown rot infection during ripening. Packhard increased fruit firmness and allowed the fruit to retain more moisture than the control fruit. Sucrose content decreased in Packhard-treated fruit compared to the controls.
Agrobacterium-mediated Introduction of Athb-7, Water Stress Gene, into Solanum spp.
Authors: Lim Hak Tae , Na Jong Kuk
Published: February 2019

A genetic transformation in Solanum spp. was performed using Agrobacterium tumefaciens: C58:pGV2260:Athb-7. Athb-7 gene, known to be related to water stress and ABA level, one of Arabidopsis thaliana homeobox genes was inserted into pBin-Hyg-Tx. Explants were placed on callus induction medium for 14 days, and then transferred on shoot induction medium. Shoot primordium appeared on callus surface after 2 weeks of culture. About 6 weeks later, 100 putatively transgenic plants were obtained, and DNA was extracted from each plant for PCR analysis. Twenty out of 100 putatively transgenic plantlets turned to be positive, having a band of 800 bp in M.W. corresponding to the hygromycin gene. Both PCR and genomic Southern hybridizations using HPTII and Athb-7 genes as probes showed that these genes were inserted into plant genome.
Analysis of Heat Tolerance in New Guinea Impatiens (Impatiens hawkeri) Utilizing Diallel Analysis
Authors: Strope Kerry M. , Strefeler Mark S.
Published: February 2019

Four heat-tolerant (`Celebration Cherry Red', `Celebration Rose', `Lasting Impressions Shadow', and `Paradise Moorea') and three non-heat-tolerant (`Lasting Impressions Twilight', `Danziger Blues', and `Pure Beauty Prepona') cultivars were identified using a Weighted Base Selection Index. These cultivars were used as parents in a full diallel crossing block with reciprocals and selfs. Progeny from five parents (25 crosses) were evaluated for heat tolerance. Four floral (fl ower number, flower diameter, flower bud number, and floral dry weight) and five vegetative characteristics (visual rating, leaf size rating, vegetative dry weight, branch number, and node number) were evaluated with emphasis placed on continued flowering under long-term heat stress. In addition, progeny from all seven parents (49 crosses) were evaluated for inheritance of adaxial leaf color, abaxial leaf color, vein color, and flower color. Significant differences were found in each data category (P < 0.001) with the exception of node number, which was not significant. Flower number varied from 0 to 2, flower diameter varied from 0 to 41 mm, floral dry weight varied from 14 to 105 mg, bud number varied from 0 to 12, branch number varied from 5 to 15, and vegetative dry weight varied from 220 to 607 mg. General and specific combining abilities of the parents were evaluated as was heritability. It was found that the four heat-tolerant cultivars had higher general combining abilities. Heat tolerance has low heritability and is controlled by many genes.
Plastochron Index—A Valuable Method in Assessing Morphological Changes Induced by Light Levels
Authors: Pennisi Svoboda V. , McConnell Dennis B.
Published: February 2019

Dracaena sanderana `Ribbon' plants were grown under 47%, 63%, 80%, and 91% shade. After 15 weeks of growth, plants exhibited marked changes in various morphological features. In order to precisely compare leaves of plants grown under different light levels the Plastochron Index (PI) of Erickson and Mickelini (1957) was used. The plastochron was defined in terms of leaf length. Various leaf morphological characteristics were examined and correlated with 1) actual leaf numbers, and 2) with leaf developmental age. A comparison between the two methods 1) and 2) revealed that overall trends displayed by leaves with a Leaf Plastochron Index (LPI) from 12 to 2 were similar to the same trends linked to actual leaf numbers. However, leaves with LPIs lower than 2 showed that under 80% and 91% shade these leaves had higher values for all studied parameters. Comparable leaves of plants in 91% shade had consistently higher values of the leaf parameters compared to plants in other shade treatments. The use of the PI enabled us to accurately compare morphological differences between plants grown under diverse light conditions.
Impact of Environmental Education Classes at Missouri Botanical Garden on Attitude and Knowledge Change of Elementary School Children
Authors: Kahtz Anthony
Published: February 2019

Two environmental education classes at Missouri Botanical Garden, “The Water Cycle: Making a Terrarium” and “The Tropical Rainforest,” were evaluated to determine their effects upon attitude and knowledge change of elementary school children. A pre-test post-test design was used to compare experimental and control groups. Data indicated that The Water Cycle: Making a Terrarium class had a positive influence on attitudes toward learning about plants and the environment; The Tropical Rainforest class had no effect. Neither of the classes significantly affected the children's attitudes toward interacting with the environment. Both classes increased the knowledge base of participating children. There were no differences between male and female attitudes or knowledge in either class. Nonformal learning experiences of this type may be a more effective means of stimulating horticultural interest among younger children than traditional classroom settings. [Affiliation. The research was conducted at Southern Illinois Univ. in the Plant and Soil Science Dept.]
Influence of Bacterial Speck Control Materials and Application Timing on Yield of Processing Tomatoes
Authors: Miyao Gene , Davis R.M. , Mauk P.A.
Published: February 2019

Bacterial speck caused by Pseudomonas syringae pv tomato is a major springtime disease of tomato during rainy weather conditions in California. Application timing as a calendar spray was compared to pre-anticipated rainfall treatments of either cupric hydroxide alone or in a combined tank-mix with mancozeb. Plots were established in grower fields with natural infestations. In some instances, moderately severe infestations of speck caused as much as a 25% reduction in yield and slight delays in fruit maturity. Timing of treatments prior to rainfall was superior to calendar sprays. Slight improvement in disease suppression was achieved with a tank mix of mancozeb with copper compared to copper alone.
Influence of Rootstock on Seasonal Levels of N and K in Petioles of Two Grape Cultivars
Authors: Wolpert J. A. , Anderson M. M.
Published: February 2019

Petioles were gathered at three times during the season: bloom, veraison, and harvest, in two trials `Chardonnay' (Ch) and `Cabernet Sauvignon' (CS). In each trial, scions were grafted onto 14 rootstocks. Petioles were analyzed for NO3-nitrogen, %N, and %K. Averaged over rootstocks, CH petiole NO3 levels were highest at harvest and lower at both bloom and veraison. A similar trend was seen in `Cabernet Sauvignon', although, on average, NO3 levels were higher on all sampling dates. In Ch, the rootstocks `Ramsey', `St George', and `110R' were among the highest in NO3, while Harmony and 1616C were among the lowest. In CS, O39-16 was among the highest in NO3, while 44-53M was among the lowest. In both cultivars and among all rootstocks, petiole NO3 was positively correlated with petiole %N in Ch, petiole K declined throughout the year, while in CS most rootstocks were relatively stable. In Ch, the rootstocks `Harmony', `1616C', and `44-53M' had high levels of K, while in CS `44-53M' was among the highest.
Turfgrass Evaluation Under Artificial Shade in the Greenhouse
Authors: LeBlanc Mark R. , McCrimmon James N.
Published: February 2019

Establishing and maintaining turfgrass in the shade is one of the most challenging problems facing turfgrass managers and home owners. A greenhouse study was initiated to determine the shade tolerance of centipedegrass [Eremochloa ophiuroides (Munro.) Hack.], carpetgrass [Axonopus affinis Chase], and selected St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] cultivars (`Floratam', `FX-10', `Seville', and `TR 6-10'). Plants were grown under artificial shade (85% polypropylene shade cloth) and full sun. Actual percent shade (%shade={PAR under shade/PAR under sun}*100) was determined by measuring photosynthetically active radiation (PAR) under shade cloth and full sun adjacent to the shade structure using a quantum sensor. Pots were arranged in a completely randomized block design with four replications. All turfgrasses, except `TR 6-10', had a significant reduction in total dry weight in the shade compared to those in the sun. `TR 6-10' had the highest root, leaf, and total dry weight in the shade. `FX-10' had the lowest root, leaf, and total dry weight in the shade. Plants grown under the shade treatment compared to those in the sun resulted in an average decrease in stolon number of 13 and in total stolon length of 170 cm. In the shade, `Floratam' and `Seville' had the longest stolon internode lengths, while `Floratam' had the longest in the sun. There were significant differences for leaf length between the shade and sun treatments, except for carpetgrass and `FX-10'. `Floratam' and `FX-10' had differences in leaf width between the sun and shade.
Qualities of Hot Water- and Calcium-treated Tomatoes after Storage
Authors: Hakim Abdul
Published: February 2019

Mature green tomatoes (cv. Vibelco) were immersed in water at 42°C for 90 min or in water (42°C for 90 min) containing 2% calcium chloride prior to storage at 2 and 15°C for 2, 4, and 6 weeks. Control fruits were immersed in 20°C water for 90 min. All fruits were subject to poststorage ripening at 20°C for 6 days. Weight loss, chlorophyll and lycopene content, pH, TSS, TA, firmness, and electrolyte leakage were determined after storage or 6 days after storage. Control fruits showed lower weight loss, less lycopene content, pH, TSS, firmer but more chlorophyll content, pitting, decay, TA, and electrolyte leakage than treated fruits. Compared to hot water-treated fruits, lower pitting, decay, less chlorophyll content, and electrolyte leakage while more lycopene content, TA, and firmness were detected in combine hot water- and calcium-treated fruits. Extended storage time resulted in higher pitting and decay. Fruits stored at chilling temperature (2°C) showed higher chilling susceptibility to pitting and decay than those were stored at nonchilling temperature (15°C).
Effect of 6-Benzylaminopurine on Sugar Profile and Senescence of Asparagus Spears Stored at 0°C
Authors: Silva S.M. , Herner R.C. , Beaudry R.M.
Published: February 2019

To help elucidate of the relationship between decline in sugar (especially sucrose) and senescence in asparagus (Asparagus officinallis L.), spears with or without tips were treated with 6-benzylaminopurine (6-BAP) and stored during 25 days at 0°C. 6-BAP was applied using a cheesecloth soaked with 100 ppm solution (30-s contact) immediately after harvesting to the tip or to the cut surface for spears that had 2 cm of the tip removed. Time-dependent profile of fluorescence, chlorophyll content, amount of fructose, glucose, and sucrose were measured for four segments from tip to the base of the spears over. Respiration rate and general visual quality were also evaluated for the whole spear on a daily basis. Three replications were used for all evaluations. 6-BAP reduced respiration rate of spears with intact tips, slowed the decline in fluorescence, and slowed chlorophyll degradation for the tip during 25 days of storage at 0°C. Respiration rate was higher in spears that had the tip removed, regardless the use of 6-BAP; however, the decline of fluorescence and chlorophyll degradation were lower in 6-BAP-treated spears. Application of 6-BAP also slowed the decline in sucrose content. 6-BAP effects were more marked when comparing with spears lacking their tip. The visual quality was higher in spears with tips that were treated with 6-BAP.
Strength of Onion-induced Human Antiplatelet Activity is Associated with Plant Development
Authors: Goldman I.L.
Published: February 2019

Much of the medicinal activity induced by vegetable Alliums is derived from a suite of organosulfur compounds formed following hydrolysis of the S-alk(en)yl-l-cysteine sulfoxides (ACSOs). One of these medicinal activities is the inhibition of blood platelet aggregation; a factor that may influence cardiovascular health. Concentrations of ACSOs in the onion bulb ebb-and-fl ow during the vegetative phase, suggesting they act as storage forms of sulfur. To examine whether medicinal efficacy paralleled these changes, I tracked bulb, leaf, and inflorescence-induced antiplatelet activity during reproductive growth of four onion genotypes. Levels of bulb-induced antiplatelet activity dropped sharply for the first 8 weeks following the end of vernalization. Leaf-induced antiplatelet activity also dropped rapidly for the first 4 weeks, but rose precipitously by week 6. The rapid loss in leaf-induced antiplatelet efficacy between week 6 and week 8 suggests a recycling of these organosulfur compounds from the leaves to the developing flower stalk and inflorescence, which would be needed for protection against insect pests. Overall, I found a dramatic decrease in bulb-induced antiplatelet activity concomitant with an initially similar decrease and subsequent increase in leaf-induced antiplatelet activity. These were complemented by the presence of high levels of antiplatelet activity induced by the inflorescence. These data indicate development mediates the medicinal activity induced by onion plants. Furthermore, the flux of antiplatelet activity induced by various plant organs suggests that this medicinal trait is serendipitously associated with the storage and cycling of sulfur in onion plants; perhaps in response to insect predation.
Comparing Pre- and Post-pollen Production Temperature Stress on Fruit Set and Fruit Production In Male-sterile And Male-fertile Tomatoes
Authors: Peet Mary M. , Sato Suguru
Published: February 2019

Peet et al. (1997) demonstrated that in male-sterile tomato plants (Lycopersicon esculentum L. Mill cv. NC8288) (MSs) provided with pollen from male-fertile plants (MFs) grown at 24°C daily mean, percent fruit set, total number and weight of fruit, and relative seediness decreased linearly as mean daily temperature rose from 25 to 29°C. The primary parameter affecting these variables was mean temperature, with day temperature at a given night temperature, night temperature at a given day temperature, and day/night temperature differential having secondary or no effect. To compare the effect of temperature stress experienced only by the female tissues with that experienced by the male tissues or both male and female tissues, MSs and MFs were grown in 28/22°C, 30/24°C, and 32/26°C day/night temperature chambers. Fruit yield and seed number per fruit declined sharply when increased temperatures were experienced by both male and female tissues (MFs). There was no fruit set in any of the MSs assigned to the 32/26°C pollen treatment, mostly because of the limited amount of pollen available from MFs. Both fruit production and seed content per fruit were also greatly reduced in MSs receiving pollen from 30/24°C grown MFs for the same reason. For plants experiencing stress only on female tissues (MSs grown at high temperatures, but receiving pollen from MFs grown at the lowest temperature), there was also a linear decrease in fruit yield as growth temperatures increased, as previously seen by Peet et al. (1997), but the temperature effect was less pronounced than that on pollen production. Thus, for this system, temperature stress decreased yield much more drastically when experienced by male reproductive tissues than when experienced only by female reproductive tissues.
Outreach Baccalaureate Programs in Horticultural Sciences at the University of Florida
Authors: Duke Edwin R. , Klock Kimberly A. , Fitzpatrick George E. , Schoellhorn Richard K.
Published: February 2019

Florida is one of the nation's leading states in citrus, foliage, vegetable, and ornamental crop production. The Univ. of Florida is the only public institution in the state of Florida that offers a bachelors degree in horticulture and /or environmental horticulture. The main campus in Gainesville is centrally located ≈400 to 500 miles from either end of the state. Changing population demographics within Florida have emphasized the necessity of developing programs to reach non-traditional students. Students who are place bound due to work or other responsibilities represent an increasing part of the potential market. The Univ. of Florida, recognizing the specialized needs of non-traditional students, established Bachelors of Science degree programs in environmental horticulture at the Fort Lauderdale and Milton research and education centers. The centers teach the same core curriculum being taught in Gainesville, but the centers also teach additional courses specific to their geographic location to allow for a tailored program. The off-campus facilities have teaching faculty at the centers to teach the courses and also use satellite technology to down link courses from Gainesville. The development of off-campus programs in Fort Lauderdale and Milton allow the Univ. of Florida to improve the effectiveness of educational programming to reach place-bound students.
Potato Growth Uniformity as Affected by Subsurface Drip and Seepage Irrigation
Authors: Locascio S.J. , Smajstsrla A.G. , Hensel D.H. , Weigartner D.P.
Published: February 2019

Growth and production uniformity of potato (Solanum tuberosum L.) as influenced by conventional seepage irrigation and by subsurface drip irrigation was evaluated in field studies during two seasons in plots 16 rows (18.3 m) wide and 183 m long. Seepage irrigation water was supplied through ditches located on each side of each plot. Drip irrigation water was distributed through buried tubes placed under the beds 6.1 m apart extending the length of the rows. Water application throughout the plots was accomplished more rapidly with the subsurface drip system and water use during the two seasons was 33% less than with the conventional seepage system. Tuber yield during the first season was similar with the two irrigation systems. During the second season, plant growth, tuber development, and tuber yield were sampled on alternate rows beginning on each outside bed, at each end of each plot, and in the middle of the plots. Irrigation method and bed location among the 16 beds had little influence of potato growth and development. With water flow from north to south, plant growth, and tuber yield were significantly higher from potatoes growing at the north end, lowest in the plot center, and intermediate from potatoes growing at the south end. These data indicate that potato production with the two irrigation systems was similar.
A Custom-built Scanner for the Estimation of the Radiation Intercepted by a Tree Canopy
Authors: Giuliani Rita , Magnanini Eugenio , Grappadelli Luca Corelli
Published: February 2019

This work proposes a methodology, by light-scanning below the canopy, to directly estimate the photon flux radiation (400–1200 nm) intercepted by single or row canopies. The system is based on the assumption that the light intercepted by the canopy, at a particular time, corresponds to the difference between the incoming potential radiation on a ground surface area (able to include the ground area shaded by the canopy), and the actual radiation influx to that area in presence of the canopy. To this purpose, light-scanning equipment has been designed, built, and tested, whose main components are two aligned multi-sensor bars (1.2 m long) and a CR10 data logger, equipped with an AM 416 Relay Multiplexer (Campbell Sci. Ltd., U.K.). The radiation sensors (BPW 14N TELEFUNKEN) were chosen because of their spectral sensitivity, along with low cost. The sensors have been placed along the bars, at 5-cm intervals, and fitted with a Teflon® diffuser to provide a cosine correction. Radiation measurements are taken moving parallelly the bars on the ground, step by step, to monitor a sample point grid (5 cm by step length). Preliminary radiation scans were taken during the summer in a 3-year-old peach orchard, trained as delayed vasette. Measurements were taken for a single canopy at various hours of the day. Moreover, radiation scans were taken at the same hour, over a 3-day timespan, while gradually defoliating the canopy. A custom-built software program has been developed for data handling. Mathcad software (Mathsoft Inc., U.S.) has been used to display the canopy shade image projected on the ground, the quantum map of the monitored area, and to calculate the light influx on the whole canopy. Moreover, the light spots on the ground determined by foliage gaps have been identified and the amount of radiation reaching the ground has been be estimated.
Comparison of June-budded and Grafted Two-year-old `Chandler' Walnut (Juglans regia) on Paradox Hybrid Root
Authors: Kelley Kathy , Ramos Dave
Published: February 2019

Fifty trees each of 1-year-old Paradox rootstock June-budded to `Chandler' walnut and 2-year-old Paradox whipgrafted to `Chandler' were planted in a 28 × 28-ft spacing on a Hanford sandy loam soil. Ten trees of each type were selected at time of planting and the number of roots, individual root diameter, trunk diameter, root dry weight, scion dry weight, and total dry weight were compared. All parameters, with the exception of root number, were significantly greater for the grafted 2-year-old rootstocks. Growth of the trees measured as trunk circumference 20 cm above the graft union was significantly greater for the grafted 2-year-old rootstocks following the first season. There was no significant different in trunk circumference between the 1- and 2-year-old rootstocks following the second or third growing seasons.
Effect of Cynodon dactylon and Amaranthus sp. Leachates on the Growth of Carya illinoinensis Seedlings
Authors: Wolf Margaret E. , Smith Michael W.
Published: February 2019

Leachates of living Cynodon dactylon (L.) Pers. and Amaranthus sp. were applied to Carya illinoinensis (Wangenh.) C. Koch. seedlings to compare effects on growth and elemental absorption. Water applied to the weed pot or control pot (no weeds present) leached through the pot and into a funnel with a tube attached, then directly into the corresponding pecan seedling pot. After 4 months of growth, pecan seedlings receiving weed leachates had less leaf area and were shorter than those watered through control pots. These results suggest that leachates from these two weed species inhibit pecan growth, independent of any competition effects.
Automated Irrigation Based on Soil Moisture Tension Reduces Run-off and Increases Productivity and Quality of Greenhouse-grown Cut Flower Roses
Authors: Oki Lorence R. , Lieth J. Heinrich
Published: February 2019

Conventional irrigation practices of cut-fl ower greenhouse crops may result in application of excess water, resulting in runoff which may pollute the environment and contaminate drinking water supplies. A computerized irrigation control system based on soil moisture tension, originally designed for potted plants, was adapted for use in cut flower production. Tensiometers equipped with a high-fl ow ceramic tip and pressure transducers were effective in monitoring the soil moisture in the root zone of plants grown in ground beds and responded to rapid changes in soil moisture. The irrigation control system using these sensors, a computer, and custom-written software continuously monitored the moisture condition of the soil, initiated irrigation when the soil dried to a specific level, and turned off the water when an adequate amount was applied. When the system was installed in a greenhouse producing roses, water use decreased while productivity (stems harvested/m2) and stem length increased substantially. The observed increases in productivity and quality can result in significant increases in profitability for commercial rose producers.
Development of DNA Isolation and Amplification Procedures for Sequence Comparisons Among Deciduous Azaleas
Authors: Scheiber S.M. , Jarret R. , Robacker C.D.
Published: February 2019

Deciduous azaleas have been gaining popularity because of their showy floral displays and adaptability to adverse environmental conditions. However, an absence of distinguishing morphological characteristics, combined with the wide variability present in most species, has created difficulties in efforts to unambiguously identify the different species. Various DNA isolation protocols were tested in order to determine the most effective methods for isolation of DNA from 22 taxa of Rhododendron for subsequent PCR amplification. DNA yields from the various isolation methods varied widely. A minimum of 50 ng/μL of template DNA was necessary for PCR amplification under standard amplification conditions. Results indicated that the effect of tissue age on the efficiency of DNA isolation was taxa-dependent. For most species, extraction of DNA from freshly harvested young leaf tissue resulted in the highest DNA yields. However, DNA yields from R. serrulatum, R. atlanticum, and R. viscosum `Lemon Drop' were highest when mature leaf tissue was used. Primers designed to amplify the internal transcribed spacer (ITS) region of the nuclear ribosomal genes and the psbD, trnK, and 16S chloroplast genes were tested in various PCR reaction mixes in order to optimize reaction conditions for amplification. Primers to both the ITS and the psbD gene resulted in satisfactory amplification in the presence of 1.5 mM MgCl2 and 50 ng template DNA.
Effect of 1-MCP on Apple Fruit Ripening and Volatile Production
Authors: Song J. , Tian M.S. , Dilley D.R. , Beaudry R.M.
Published: February 2019

Aroma production by apple fruit is an important quality criterion and has been found to be a fruit-ripening-related process. 1-Methylcyclopropene (1-MCP), an effective ethylene action inhibitor, was used to study the relationship between volatile biosynthesis, ethylene action, and fruit ripening in `Golden Delicious' apple fruit. Pre-climacteric fruit were treated with 1-MCP vapors at a concentration of 500 parts per billion (v/v) at 23°C. 1-MCP prevented the climacteric rise of ethylene production, respiration, and volatile production, while untreated fruits developed typical climacteric changes in ethylene production, respiration and volatile production. Applying ethylene at 15–20 parts per million for 24 hr 11 days after 1-MCP treatment could not overcome the effect of 1-MCP, suggesting that 1-MCP inhibited ethylene action irreversibly. Interestingly, when 1-MCP-treated tissue were fed butanol and butyric acid, they converted these compounds to their corresponding esters butylacetate and butylbutanoate. Thus precursor supply is apparently limiting and appears to be ethylene-dependent.
Using a Digital Camera to Assist in Problem Identification by County Extension Field Staff using Electronic Mail
Authors: Marr Charles W. , Upham Ward
Published: February 2019

A Casio QV-10 digital camera was used to photograph images. A portable of desktop computer was used to convert the images to a digital image file and attached them to an electronic mail message sent from field extension staff to campus-based horticulture specialists. Images were examples of insect, disease, or cultural problems for diagnosis, plant identification questions, or an overview of a lawn or landscape. Electronic transmission allows immediate identification for a low cost, enables the specialist to see what is being described, and results in images that can be stored for news releases, newsletters, or problem warnings. Limitations exist for resolution and size of objects photographed and these will be described and demonstrated along with other problems and limitations encountered. Cameras are presently available in all five area extension centers and in several individual county extension offices. Two cameras are available for testing and demonstration purposes by individual agents. Transmission from a cellular phone from a remote location is possible, but has not been tested as of this writing. A campus-based “horticulture response center” was established to provide immediate responses to questions from field staff.
Preplant Fumigation of Reset `Lisbon' Lemon Trees
Authors: Maurer M.A. , Matheron M.E.
Published: February 2019

A field study was conducted near Mesa, Ariz., in a mature lemon grove with reset `Lisbon' lemon trees (Citrus limon) on a Carrizo citrange rootstock to determine the effects of stump removal and preplant soil fumigation on reset tree growth and development. Treatments consisted of resets planted with or without tree stumps and in addition with or without preplant Vapam. Pretreatment soil samples average 2.1 propagals of Phytophthora per gram of soil; however, after Vapam treatments, Phytophthora was not detected in the treated plots. In subsequent soil sampling for 2 years, Phytophthora was detected in only one plot treated with Vapam. Tree growth and vigor was greatest for resets that had stumps removed and preplant Vapam followed by resets with stumps present and preplant Vapam based on visual ratings and trunk diameter measurements. In addition, resets without stumps were more vigorous than resets where stumps were present.
An Analysis of the Seed Coat Pigments in Eight Different Genotypes of Phaseolus vulgaris L.
Authors: Beninger Clifford W. , Hosfield George L. , Nair Muraleedharan
Published: February 2019

Dry bean (Phaseolus vulgaris L.) seed coat color is determined by the presence and relative amounts of phenolics, flavonoids, and anthocyanins present in the lumen of epidermal cells. Some of these chemicals may interact with proteins of the cotyledon to form complexes that render beans hard to cook and digest. Eight genetic loci control seed pigment chemistry. When all eight loci are dominant, a shiny black seed coat results, but recessive substitutions at one or more loci yield colors ranging from white, yellow, and brown to dark violet. In order to relate Mendelian genes for seed coat color to the pigments formed, we studied eight genetic stocks that had recessive substitutions at one or more color-determining loci in an otherwise all-dominant genetic background. Seed coat from each genotype was extracted exhaustively with hexane, EtOAc, MeOH, MeOH:H2O 1:1, and H2O 100%. Silica gel thin-layer chromatography (TLC) (solvent system CHCl3:MeOH 4:1) analysis of the MeOH fraction showed that one genotype had no phenolic compounds and two had only simple phenols. Once flavonol glycoside was present in relatively large amounts in four of the genotypes, but absent in genotypes with anthocyanins. Cellulose TLC (2-dimensional, Butanol:Acetic Acid:H2O 4:1:5 first dimension, 1% HCl second dimension) of the anthocyanin-containing genotypes showed that the presence of one flavonol and three anthocyanidin-3-glycosides (UV spot color and color shift with NH3). The relative importance of the seed coat chemicals in digestibility and their antioxidant will also be discussed.
Location of Four Morphological Markers (dgs, blu, arg, and y) in a Molecular Linkage Map of Common Bean
Authors: Beltran Gino , Jung Geunhwa , Bassett Mark , Nienhuis James
Published: February 2019

The development of a complete linkage map including both morphological and molecular markers is important to understand the genetic relationships among quantitatively and qualitatively inherited traits in common bean. The objective of this study was to identify RAPD markers linked to genes for four morphological traits using bulked segregant analysis and to map the markers to a molecular linkage map previously constructed in common bean. Three segregating populations were evaluated. Two BC2F2 populations with dgs (dark green savoy leaf) and blu (blue flower) induced mutant was developed with a Florida breeding line 7-1404 and 5-593 as the recurrent parent. In addition, a BC3F2 population with the y (yellow wax pod) and the arg (silvery green pod) mutants was developed from the Lamprecht line PI 527858 and 5-593 as the recurrent parent. RAPD markers linked in coupling to the morphological traits were detected to be 4.1 cM, 4.3 cM, 7.3 cM, and 12.3 cM distant from the dgs, blu, y, and arg genes, respectively. The linked RAPD markers were mapped in the molecular linkage map previously constructed using recombinant inbred population of the cross PC-50 × XAN-159. In this linkage map, we observed a linkage between the C locus and blu gene whose location was not previously known. In addition, a linkage between an abaxial leaf pubescent gene and dgs gene was observed. These results indicate that integrating morphological markers and molecular markers can result in a more complete genetic linkage map in common bean.
Micropropagation of Wetland Plants: Sagittaria latifolia
Authors: Kane Michael E. , Lane Charles
Published: February 2019

Many wetland plant species used for aquascaping and wetland revegetation projects are collected from donor wetland sites for planting elsewhere. Increased demand for wetland plants has lead to over-collection and subsequent environmental damage to these donor sites. Micropropagation provides an ecologically sound alternative to field collection and allows for production of under utilized wetland species and genotypes that are either slow-growing or difficult to propagate using conventional methods. Sagittaria latifolia Willd. (Duck-potato), a rhizomatous herbaceous wetland species, was established in vitro from surface-sterilized lateral and terminal rhizome shoot-tips cultured in liquid basal medium consisting of half-strength Murashige and Skoog mineral salts, 0.56 mM myo-inositol and 1.2 μM thiamine supplemented with 87.6 mM sucrose. Prior to multiplication, responsive Stage I cultures were indexed for cultivable bacteria and fungi. Shoot multiplication occurred in vitro through formation of multiple node rhizomes bearing terminal shoots. Duck-potato exhibited a high sensitivity to relatively low benzyladenine (BA) levels. Maximum rhizome and shoot production occurred from single shoot explants initially cultured on agar-solidified BM supplemented with 4.0 μM BA for 28 days. However, repeated subculture on BM supplemented with greater than 2.5 μM BA resulted in increased mortality, reduction in multiplication rate, or production of dormant corms. Consistent shoot multiplication (four to five shoots/explant) was possible in the presence of 1.5 μM BA. Maximum (100%) acclimatization and rooting was attained by direct sticking of Stage II microcuttings in soilless growing medium contained in 38 cell plugs. Production of salable plants bearing multiple rhizomes was possible within 6 weeks post-transplant. Preliminary observations indicate that corm formation in Sagittaria latifolia may be mediated by photoperiod.
Effect of Different Organic Compounds and Medium Consistency on Temperate Orchid (Orchidaceae) Micropropagation
Authors: Szendrak Erika , Read Paul E.
Published: February 2019

The effects of organic compounds most commonly used for orchid micropropagation and the physical condition of the medium were investigated for the development of young temperate orchid protocorms. Separate experiments were conducted with five different temperate orchid species: Dactylorhiza fuchsii, Dactylorhiza maculata, Dactylorhiza majalis, Orchis morio, and Ophrys lutea. Small 2- to 4-mm-wide protocorms were placed in baby food jars (three per jar) containing 50 ml modified FAST medium (Szendrak and R. Eszki, 1993) supplemented with one of eight treatments in a split-plot design with five replications. Both the liquid medium (gyrotary shaker, 125 rpm) and the gelled medium (8 g agar/L) were supplemented with one of the following compounds: 2 g peptone/L; 100 ml coconut water/L; 1 g casein+1 g lactalbumin/L; and 10 g glucose/L as a treatment with a defined compound. All treatments were kept in the dark at 25°C. The number of protocorms/jar were counted weekly over a 6-week-long period and the size and fresh weight of protocorms were measured at the end of the 6th week. In most cases, the liquid medium increased proliferation and the size of the protocorms. However, generally after the 4th week on liquid medium, the development of the protocorms often stopped, but it continued on the gelled medium till the end of the experimental period. The media supplemented with the undefined organic compounds showed a much better effect than the medium supplemented with glucose. Generally peptone and coconut water led to the best development of protocorms, but this varied with species. The development of protocorms into plantlets was normal in all cases.
Water Conservation in the Urban Landscape
Authors: Kjelgren Roger , Rupp Larry
Published: February 2019

As populations become increasingly urbanized, landscape water conservation becomes more important. Landscape water consumption can increase municipal water use up to 4-fold during the growing season, and account for half the total yearly water use. Landscape water conservation is important in decreasing peak summer water demand to reduce the strain on delivery systems, and to reduce total demand so that development of new sources can be forestalled. Potential water savings from existing landscapes can be estimated by comparing historical usage gleaned from water meter readings to plant water needs estimated from reference evapotranspiration. Estimating water needs for turf is straightforward because of the few species involved and the uniformity of turf landscapes. Estimating water needs of woody plants is more difficult because of the heterogeneity of woody plants and how they are used, and woody plants respond to evaporative demand differently than turfgrass. Many woody plants will actually use less water as reference evapotranspiration increases due to stomatal closure induced by high leaf-air vapor pressure gradients. Landscape water is then conserved by either applying water more effectively in scheduling when and how long to irrigate based on estimating water use again from reference evapotranspiration, or by replacing areas in turfgrass with plants more-adapted to the existing conditions. Encouraging water conservation by end users is the final and largest challenge. Automated irrigation systems makes wasting water easy, while conserving water takes more effort. Education is the key to successful landscape water conservation.
Deficit Irrigation in Prunes: Getting More with Less Water
Authors: Shackel Kenneth A. , Lampinen B. , Southwick S. , Goldhamer D. , Olson W. , Sibbett S. , Krueger W. , Yeager J.
Published: February 2019

Prunes trees are believed to be relatively tolerant of water stress, and because prune fruit are dried, a low fresh to dry weight ratio of the fruit will reduce energy requirements for fruit drying and will represent an economic benefit to the grower. In previous research, we found that, under some orchard conditions, irrigation deprivation was associated with a number of economically beneficial effects, including a lower fresh to dry weight ratio of the fruit, increased return bloom, and final saleable crop yield. Analysis of these results was complicated by the effects of irrigation on alternate bearing, and the fact that tree water stress could be substantially different under different soil conditions for the same level of irrigation deprivation. Taking these factors into account, however, indicated that economic yield in prune could be maintained or increased by managing trees at a moderate level of water stress. An experiment was established to determine whether midday stem water potential could be used to guide irrigation and achieve a target level of water stress during the growing season, and whether a moderate level of water stress would be economically beneficial to prune production. By managing prune trees at a moderate level of water stress (midday stem water potential reaching about –1.5 Mpa by the end of the season) over 3 years, an average savings of 40% in applied irrigation water was obtained. Modest increases in return bloom, and an improved fruit dry to fresh weight ratio, occurred in moderately water stressed trees, although overall yield was not changed. The substantial savings in water, without reducing yield, should represent a net economic benefit to growers, depending on the price they pay for water.
A Horticulturist's Perspective of Agricultural Databases for Decision Support
Authors: Gomez R.E.
Published: February 2019

Agricultural databases have existed in one form or another from time immemorial. However, their usefulness to horticulturists has not been the greatest. Many databases exist today that one can use to research developments in agriculture. However, none exists that allow a horticulturist to rapidly focus on a subject with the assurance that the information is accurate. Accuracy of information, especially that which can readily be used by Extension horticulture specialists and agents, is not guaranteed. The Cooperative Extension System (CES) through several state specialist and the National Program Leader at USDA developed a list of current and available Extension literature on three distinct subjects during the early 1980s. These lists were compiled by the Specialists and were placed in an electronic format (bulletin board) available through the nascent CES electronic network. This effort was abandoned 3 years after inception due to lack of use by CES staff. One of the reasons for not using these lists so as not to reinvent the wheel was that electronic communication at that time was very expensive. Other reasons were that it was cumbersome and did not include text. There was no quality assurance of any kind. In the case of this primitive database in horticulture, personal contacts were much more useful and convenient. Indeed there are many databases that have horticultural subjects included and many more are being created. These are only marginally useful to us in horticulture. There is a shining nova in our horizon today. HortBase offers the best chance we in horticulture, and especially in Extension horticulture programs, have of being able to use data (written and hopefully in other media) that meet our specific requirements. HortBase will be a peer-reviewed accumulation of our experiences and experiments whether in the classroom or in the field. It has a great potential to become one of our best tools for program development and delivery. We in horticulture, whether at the society, national, state, region, or county level, must help in the development and maintenance of this rising star so that it truly reaches its full potential.
Synthesis of Volatile Flavor Components in Food Crops during Cooking
Authors: Kays Stanley J. , Wang Yan
Published: February 2019

Using the sweetpotato as a model, we identified precursors of critical flavor volatiles by fractionating, based upon solubility, raw roots into major groups of constituents. Volatile thermophyllic products from the individual fractions were analyized and compared to those from non-extracted root material. Volatile components were seperated and identified using GC-MS and quantified using internal standard methodology. Mechanisms of synthesis of flavor volatiles via thermophyllic reactions will be discussed, as will postharvest treatments that can modulate eventual aromatic properties of cooked plant products.