bluuebunny/crossref_metadata_2025 huggingface dataset:
108 Shoot Regeneration from Ovaries of Various Cultivars of Hosta
Authors: Williams David J. , Al-Juboory Karim H.
Published: February 2019

The objective of this study was to evaluate the ability of various cultivars of Hosta ovary explants to generate adventitious shoots and obtain variegated plants in vitro. Immature inflorescences along with 8 to 10 cm of scape were harvested from Hosta cultivars. The ovaries were prepared for culture by cutting immature florets before anthesis. The florets were first cut just above the top of the immature ovary to remove the sigma, style, corolla, and anther. Then the calyx and filament bases were also removed. Ovaries were transversely cut into halves and transferred to baby jars containing Hosta initiation medium supplemented with naphthaleneacetic acid (NAA) at 0.5 mg/L and 6-benzylamino purine (BA). The explants produced adventitious shoots from ovary base via organogenesis. The number of shoots regenerated from shoot tips and callus increased linearly with repeatedf subculturing on MS medium. This method would provide an effective alternative to conventional propagation crown division of Hosta, an expensive and slow process. The long-term goal of this project is to improve Hosta.
112 The Influence of Plant Growth Regulators and Light Levels on Shoot Morphogenesis from Leaf Explants of Highbush Blueberry
Authors: Cao Xiaoling , Hammerschlag F.A.
Published: February 2019

As part of a program to develop transgenic highbush blueberry (Vaccinium corymbosum L.) cultivars, studies were conducted to determine optimum conditions for high efficiency shoot regeneration from leaf explants of in vitro-propagated shoot cultures. The effect of either thidiazuron at 1 or 5 μM, or zeatin riboside at 20 μM, and two lit levels (18 ± 5 or 55 ± 5 μmol·m-2·s-1) on shoot organogenesis were investigated. With the exception of `Bluecrop', which did not regenerate shoots, maximum shoot regeneration of 13, 12.7, 12.6 and 4.6 shoots per explant for cultivars Duke, Georgiagem, Sierra, and Jersey, respectively, occured on regeneration medium with zeatin riboside and under a light intensity of 55 μmol·m-2·s-1. Whereas `Duke' regenerated equally well on regeneration medium with either zeatin riboside or 5 μM thidiazuron, regeneration frequencies for `Georgiagem' and `Sierra' were significantly higher on zeatin riboside. A light intensity of 55 μmol·m-2·s-1 significantly increased regeneration of cultivars Duke, Jersey, and Sierra on zeatin riboside, but inhibited regeneration of Duke on 5 μM thidazuron.
114 In Vitro Multiplication of Potato (Solanum tuberosum L.) as Affected by the Microcutting Characteristics
Authors: de L. Fortes Gerson R. , França Rosilene , Dantas Adriana C. M.
Published: February 2019

This work was carried out in the Tissue Culture Laboratory of Embrapa Temperate Climate aiming to maximize the protocol for in vitro culture of potato cv. Baronesa. The treatments consisted of multiplication of microcuttings with one, two, or three buds with/without leaves and originated from different regions of the shoot: apical, middle, or basal. Each treatment was repeated five times with each replication composed of five explants that were inoculated in 250-ml flasks with 40 ml of the medium containing MS salts and vitamins added to: sucrose (30 g·L-1), myo-inositol (100 mg·L-1), agar (6 g·L-1). The pH was adjusted to 5.6 before autoclaving. After inoculation, the flasks remained in a growth room at 25 ± 2 °C, 16-h photoperiod, and 19 μmol·m-2·s-1 light intensity provided by cool-white fluorescents lamps. Observations were done every 5 days. Final evaluation was performed after 30 days. It was observed that basal microcuttings provided longer shoots and that microcuttings with leaves bore the best ones. This kind of explant also favored a higher number of shoots, axilary buds, and better multiplication rate. The presence of leaves in the microcutting is important when basal explants are used once it can improve the number of axillary buds and the rate of multiplication. The higher the number of buds in the microcutting the lower the rate of multiplication. The in vitro multiplication of potato could be improved by using one-leaf bud basal microcutting.
116 Somatic Embryogenesis and Organogenesis in Cowpeas
Authors: Marsh Lurline
Published: February 2019

Four cowpea [Vigna unguiculata (L). Walp] genotypes; IT 82E-18, IT 82E-16, Pinkeye Purple Hull, and Coronet were tested for somatic embryo formation and embryogenesis. Explants were 3-week-old cotyledons from which the embryonic axes were removed. Cotyledons were cultured in eight media combinations representing modifications of two media, one containing Murashige and Skoog Basal salt with B5 vitamins (MSB), 500 mg/L casein-hydrolysate (CS), 500 mg/L sodium chloride, 3% sucrose, 0.7% agar, 2mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.5 mg/L benzylamino purine, and the other containing (MSB), 3% sucrose, 40 mg/L 2-4-D and 0.2% gellan gum. After 1 month, 40% to 100% of explants produced calli and few produced shoots. Subcultured shoots in MS with 0.1 mg/L indole-3-butyric acid (IBA) or with IBA and 0.5mg/L kinetin (KT) failed to produced roots. The only green cotyledonary stage embryo was produced on this latter medium. Subculture of calli in MSB containing CS, mannitol, sucrose, agar, indoleacetic acid, and KT produced cream-colored globular embryos, roots, and a few leaves.
124 Evaluation of the Chemical Characteristics of Three Organic Residues and the Effect of Their Use on the Environmental Medium
Authors: Bouden Mondher , Rioux Jacques-Andre
Published: February 2019

The richness of the organic residues in certain fertilizing elements justifies their valorization in horticulture. However, their contents in pathogenic and toxic elements can restrict their use. In this context, this study was conducted in order to evaluate the effect of three organic residues on the environmental medium and the risks of water contamination by the release of heavy metals. Physocarpus opulifolius `Nanus' was transplanted into four substrates. The control substrate contained 4 peatmoss: 5 composted conifer bark: 1 fine crushed gravel (by volume). The three other substrates (25% of peatmoss was substituted by organic residue) contained 10% of fresh bio-filters (FBF), 10% of composted sewage sludges (CSS), or 10% of de-inking sludges (CDS). The pots (5l) were placed in plastic vats and the drainage water was recovered in vessels (17l). The experimental design was in complete blocks with six replications. Samples of the drainage water were collected every 2 weeks for analysis. The pots were fertilized every week (400 mg/Ll of N) and growth parameters were statistically analyzed by ANOVA. The chemical analysis of the residues proves that they contain weak concentrations in organic contaminants. There is an accumulation of in drainage water following the fertilization; the same applies to sulfates and potassium. On the other hand, heavy metals are not released in important concentrations and so the lead, zinc, manganese, and copper contents do not exceed the desirable limits. Moreover, the Physocarpus plants produced in CSS substrates had a growth significantly larger than those plants produced in FBF or CDS substrates. The three organic residues do not constitute a risk of pollution for the environment.
132 Fertilization Methods to Match Nutrient Supply with Demand for Potted Chrysanthemum
Authors: Catanzaro C.J. , Sauve R.J.
Published: February 2019

A greenhouse study was conducted in Autumn 1998 using standard cultural practices for potted chrysanthemum [Dendranthema × grandiflorum (Ramat.) Kitamura] to determine how fertilization affected plant growth and quality and nutrient leaching. Fertilization treatments included constant liquid fertilization until anthesis (LFA), constant liquid fertilization until disbud (LFD), slow-release resincoated fertilizer (SRF), and no-fertilizer control. Frequency of irrigation was determined gravimetrically, and leaching fractions maintained near 0.2. Plant growth and quality for LFA, LFD, and SRF met commercial crop standards. Nearly 60% of the total nitrogen applied with LFA was applied during the 4 weeks between disbud and anthesis, due to increased water demand. During the same period when liquid fertilization was discontinued for LFD, leachate electrical conductivity (EC) levels dropped from 4 to <1 dS·m-1. Leachate EC levels for LFA at anthesis remained high, but were <1 dS·m-1 for the other treatments. LFD and SRF drastically reduced the total amount of nutrients applied during the course of production compared with LFA. Use of an appropriate slow-release fertilizer or discontinued use of liquid fertilizer at disbud allow soluble salt levels to decrease during the latter weeks of the mum production cycle, when nutrient demand is low and water demand is high.
134 Growth, Photosynthesis, Fruit Yield, and Quality of Greenhouse Tomato Grown in Open or Closed Rockwool Production Systems with Different Nutrient Feedings
Authors: Hao Xiuming , Papadopoulos Athanasios P.
Published: February 2019

Two long-season tomato crops (Lycopersicon esculentum Mill. cv. Trust; in 1996 and 1997) were grown in an open rockwool system (conventional culture method) and in closed rockwool culture systems with different nutrient feedings to develop a closed tomato production system with zero discharge of nutrient solutions to the environment. The tomato grown in the closed rockwool systems with a modified rockwool or nutrient film technique (NFT) feeding formula achieved similar marketable yield as the tomato grown in the conventional open rockwool system. Similarly, there were no differences in early plant growth and photosynthesis, total plant biomass and biomass partitioning, fruit yield, or fruit size and grades. The tomato plants grown in the closed rockwool systems senesced slower, as demonstrated by higher photosynthesis in old leaves, and had better root systems than the plants grown in the conventional open rockwool system. The fruit quality of tomato produced in the closed rockwool systems was better than that of tomato produced in the open rockwool system in one of two crops. These results demonstrated that the closed rockwool system with optimized nutrient feeding is an economically and environmentally sound alternative to the conventional open rockwool production method.
135 Tillage Systems and Fertilization Methods for Staked Tomatoes
Authors: Wyatt Jim E. , Howard Don D. , Tyler Don D. , Canaday Craig H.
Published: February 2019

Reduced and no-tillage vegetable production is gaining in acceptance in the Southeastern United States. Conventional till, strip-till, and no-tillage systems with different methods of nitrogen application in staked tomatoes were studied in Tennessee. Conventional tillage plots were prepared by disking and harrowing, strip till plots were cultivated ≈16 cm deep with a rear-tine tiller (≈50 cm wide), and no-till plots were established in chemically killed wheat with no cultivation. Four nitrogen treatments were applied at 67.2 kg·ha-1 N using liquid KNO3. The treatments included applying the N either 1) in a 54-cm strip or 2) in a 108-cm strip over the row, 3) by banding ≈10 cm on each side of and ≈10 cm below the row, or 4) by injecting into the drip irrigation system in increments of 11.2, 22.4 and 33.6 kg·ha-1 N at 2, 4, and 6 weeks after transplanting, respectively. Tillage had little effect on tomato yield but the strip till and no-till plots allowed cultivation or spraying soon after a rainstorm. The improved trafficability was a distinct advantage over the conventionally tilled plots in the study. Total yield was significantly higher in strip tilled plots, but within fruit size categories (small, medium, large and extra large) no differences were found due to tillage system. The fertilizer treatments in which N was placed in 54- or 108-cm strips over the row produced the highest yield of early large and early extra large fruit, which are usually the most valuable portion of the crop. Banded and injected nitrogen treatments tended to produce large amounts of fruit late in the season, a period when tomato prices are generally lower.
147 Development of a Multimedia Ornamental Plant Database for the World Wide Web
Authors: Philp Kimberly A.M. , Brand Mark H.
Published: February 2019

The growth of the ornamental plant industry has rapidly increased over the past several years, creating a strong demand for well-trained graduates and industry workers. It is vital for a person entering this industry to have a solid and broad plant material background. The best ways to learn, sell, and teach plants are through visual materials. Currently, there are few cost-effective resources that provide a person with all the visual information needed to learn plants. To better serve the students and industry workers, the Univ. of Connecticut has developed a free multimedia ornamental plant database on the World Wide Web. The plant database focuses on plants for the New England area (USDA zone 6 and lower). This website brings detailed textual information, thousands of pictures, and audio pronunciations together in one complete package. Plant characteristic information (textual and pictorial) consists of habitat, habit and form, summer foliage, autumn foliage, flowers, fruit, bark, culture, landscape uses, liabilities, ID features, propagation, and cultivar/variety. The major factors and decision processes involved in developing an educational Web site, with emphasis on usability and accessibility are considered. The target audience for this Web site is students as well as the nursery and landscape industry workers, agricultural consultants, extension personnel, landscape architects, and the gardening public.
150 Influence of Childhood Environmental Experiences on Adult Sensitivities to Urban Forests
Authors: Lohr Virginia I. , Pearson-Mims Caroline H.
Published: February 2019

Community involvement is critical for the continued vitality of the urban forest. To encourage this involvement, an understanding is needed of what promotes shared stewardship as well as of different cultural perspectives regarding trees. A survey of the general public in 109 large metropolitan areas across the continental U.S., a culturally and ethnically diverse group, was conducted. Two thousand adults were surveyed to assess the extent of their childhood experiences with nature, their current attitudes toward urban forests, and their demographic backgrounds. Respondents were questioned particularly about their earliest experiences with nature and their current understanding and appreciation of the urban forest. Other researchers have examined the relationship between childhood contact with nature and attitudes toward nature among professionals in environmental fields, but this relationship has not been explored in the general public. Correlations between survey respondents' memories of childhood contact with nature, their current perceptions of the urban forest, and the influence of their cultural and ethnic backgrounds will be presented. For example, respondents who reported very easy access to nature as children were likely to agree strongly that trees should be planted in business districts to reduce smog. Results from this survey may be applied in programs to teach children about trees and gardening, thus better tailoring these programs to engender future appreciation for the urban forest. Raw data from this survey will be made available to other researchers.
151 The Effectiveness of Assessing a Vocational Horticulture School Curriculum for Juveniles on Probation
Authors: McGuinn Catherine , Relf Diane
Published: February 2019

A 17-week vocational horticulture curriculum was assessed for it's effectiveness in changing attitudes about personal success and job preparation, presenting horticulture/landscaping as an appropriate career, developing an attitude of appreciation and fostering of the environment, and strengthen social bonds to reduce delinquent behavior. Pre-tests/post-tests based on Hirsch's tests of social bond for juvenile delinquents were developed and administered to address attitudes toward school, teachers, peers, views, and the environment. A separate pre-post test dealt with career and aspirations. Results of these tests were compared to tests administered at a comparable urban program. Behavioral records for one semester before and semester during the horticulture curriculum were compared. Daily journals maintained by service learning students volunteers were analyzed for observational themes and combined with teachers observations. Success of the program was related to students desire and ability to get summer internships and/or employment in horticultural settings. Due to the limited size of the study group (6) and the school policies limiting follow-up data collection at 6 or 9 months, the results of the study must be seen as trends suggesting future research direction and supporting the continued work being conducted a Norfolk Botanic Gardens.
154 Indiana CropMAP and New Crop Compendium: New Developments from Purdue's Center for New Crops and Plant Products
Authors: Whipkey Anna , Simon James E. , Janick Jules
Published: February 2019

NewCROP (http://www.hort.purdue.edu/newcrop) is a crop resource online program that serves Indiana, the United States, and the world. This crop information system provides useful resources to encourage and assist new rural-based industries and to enhance agricultural sustainability and competitiveness. The NewCROP site currently averages 150,000 hits per month. Indiana CropMAP is the first module in a proposed nationwide, site-specific, retrievable system that will serve the crop information needs of individual growers, marketers, processors, government agencies, cooperative extension personnel, and industry. For each county in Indiana, users can access the most recent US agriculture statistics, county extension offices, lists of crops that are currently grown, recommended alternate crops, and experimental crops. Detailed crop information, much of it specific to Indiana, can be accessed directly or through a crop search. The New Crop Compendium CD-ROM was produced by the Purdue University Center for New Crops and Plant Products in cooperation with the United Nations Food and Agriculture Organization (FAO). The New Crop Compendium CD-ROM, a searchable resource of new crop information, was edited by Jules Janick and Anna Whipkey and contains the entire text and figures from the proceedings of the three National New Crop Symposia: J. Janick and J.E. Simon (eds.). 1990. Advances in New Crops. Timber Press, Portland, Ore.; J. Janick and J.E. Simon (eds.). 1993. New Crops. Wiley, New York; and J. Janick (ed.). 1996. Progress in New Crops. ASHS Press, Alexandria, Va. The New Crop Compendium provides a valuable source of information on new, specialty, neglected, and underutilized crops for scientists, growers, marketers, processors, and extension personnel. It employs an intuitive, easy to use interface. Purchase information can be found at the following url: http://www.hort.purdue.edu/newcrop/compendium/order.html.
159 Ornamental Treatment-production Wetlands for Water Quality Improvement
Authors: Holt Thomas C. , Maynard Brian K. , Johnson William A.
Published: February 2019

Degraded water quality is a growing concern across the northeast and in many cases may be linked back to agricultural operations as nonpoint sources of nitrate and phosphorous pollution. Constructed wetlands have emerged as effective, low-cost methods of water treatment that have the potential to reduce agricultural nonpoint source pollution and contribute to agricultural sustainability. However, the costs of implementing treatment wetlands as a BMP are high, with little opportunity for cost recovery. We have initiated, at a wholesale plant nursery in Rhode Island, an economical solution to treating nursery runoff that incorporates into a treatment wetland the wholesale production of native and ornamental wetland plants. Our goal is to demonstrate how nursery growers may produce a high-demand crop while addressing nonpoint source pollution on their land. Over the next few years, we will evaluate the economic impact of converting nursery production space into treatment wetland production space. We also will research the feasibility of enclosing treatment wetlands in passively heated polyhouses to facilitate the year around treatment of agricultural runoff. Information gathered from both the on-farm demonstration and research sites will be extended to farmers and other agricultural businesses or professionals through outreach programming. The theory, objectives, and construction of the demonstration treatment-production wetland will be presented.
162 Use of Bush Morning Glory and Ornamental Sweetpotato `Blackie' as a System for Teaching Grafting Principles in Undergraduate Horticulture Courses
Authors: Maxwell Douglas , Lineberger R. Daniel
Published: February 2019

Bush morning glory (Ipomoea carnea ssp. fistulosa) and the ornamental sweetpotato cultivar Blackie (Ipomoea batatas) were used to demonstrate various grafting methods to students in an undergraduate horticulture class at Texas A&M Univ. Grafting the vining species onto the upright shrubby species produced an attractive ornamental plant and illustrated that graft union formation was independent of plant morphology. Graft “take” was high, ranging from 83% to 100%. Stock plants of both species are easily maintained in the greenhouse and can be rooted readily to “batch up” plants for laboratory sessions. Cuttings from both species can also be used in various rooting experiments, with cuttings of sweetpotato rooting in days rather than weeks, as with some species. The wide difference in morphology and coloration of these two plants also creates an easily distinguishable division between stock and scion.
163 Fostering Active Learning through Cooperative Learning Techniques
Authors: Schuch U.K. , Nonnecke G.R.
Published: February 2019

Iowa State Univ. is committed to improve student learning and supports faculty and staff through Project LEA/RN (Learning Enhancement Action/Resource Network) workshops and continuous training. Project LEA/RN teaches cooperative learning techniques that are known to improve student interest in the subject, allow active participation, improve understanding and retention of the material, and encourage learning inside and outside the classroom. Three learning techniques that have been used successfully in our lecture and laboratory classes ranging from 20 to 100 students per class are: turn to your partner (TTYP), note-taking pairs (NTP), and jigsaw. In TTYP, the instructor asks a question and students formulate an answer individually, then share the answer with a partner, listen to the partner's answer, and finally create a new answer through discussion. NTP can be used after new material has been presented. A student compares notes with their partner, both add/correct their notes, share key points with a partner, and carefully listen to the partner's keypoints. In the jigsaw exercise, students who had the same assignment compare information they have prepared with each other and then with the entire class. In all exercises students are made accountable by the instructor who calls randomly on individuals to share their answers with the class. Examples of how to use these techniques and the interpersonal skills acquired and practiced during these exercises will be discussed.
166 An Internet Course Tool for Teaching Landscape Horticulture Courses
Authors: St. Hilaire Rolston
Published: February 2019

A World Wide Web course tool (WebCT) developed by the Univ. of British Columbia was used as an aid in teaching landscape plant identification and landscape construction at New Mexico State Univ. WebCT is a set of educational tools that are easily incorporated into the teaching of classes. Course assignments, slides of plant materials, and course grades were posted on the Web. A chat tool provided real-time communication among students and the electronic mail facility allowed personal communication with a student or communication to all course participants. Access to WebCT is controlled by username and password, so course material is restricted to course participants. Student progress through materials posted on the Web site can be monitored because WebCT maintains records about student access to web pages. Course statistics, such as the total number of hits per page, time spent on each Web page, and the date and time when student first accessed or last accessed the Web site, are kept by WebCT. Students were able to review highly visual material such as slides of landscape plants at their own pace. Also, students had quick access to their grades.
168 Agronomic Performance and Ear Nutrients of Two Sweet Corn Culitivars Grown by Conservation Tillage
Authors: Makus D.J.
Published: February 2019

In Spring 1998, two sweet corn (Zea mays var. rugosa) cultivars were grown under three tillage systems, conventional cultivation, ridge tillage (RT), and no tillage (NT), which had been in continuous management since Fall 1994. Nitrogen (as NH4NO3), the only fertilizer used, was applied twice at 60 kg/ha. Sweet corn yields were not influenced by tillage system, but average ear weights tended to be smaller under NT (P < 0.17). Ear quality attributes, which included ear weight, length, diameter, dry matter, and incidence of earworm damage, were greater in the later-maturing `G-90' cultivar than in `Sensor'; but tillage system had no influence on these attributes. Cultivars supported different weed species underneath their canopies. `Sensor' allowed more light penetration and sustained higher weed biomass than did the taller `G-90' plants. Weed biomass was higher under RT and NT. Seasonal soil moisture was lowest in the RT plots, but only in the 0- to 15-cm profile. Soil temperatures (unreplicated) at the 15-cm depth were similar between cultivars and tillage treatments over the growing season. The earlier-maturing `Sensor' generally accumulated more ear mineral nutrients (P, S, NO3, Ca, Na, Zn, Mn, Al, and B; dry weight basis), but had lower dry matter (percentage) than did `G-90'. Cumulative nutrient levels tended to be lowest in NT-grown ears (P < 0.08). Soil sampled at 0- to 5-, 10- to 15-, and 25- to 30-cm depths generally had higher concentrations of nutrients toward the surface, and NT soils had the steepest nutrient gradients, with the exception of Na and NO3. Total soil salts were reduced by RT and NT, but C: N ratio remained unchanged between tillage systems.
173 Effects of Cover Crops and Tillage on Sweet Corn Production
Authors: Cline Gary R. , Silvernail Anthony F.
Published: February 2019

A split-plot factorial experiment examined effects of tillage and winter cover crops on `Merit' sweet corn in 1994, 1995, and 1996. Main plots received tillage or no-tillage. Cover crops consisted of hairy vetch, winter rye, or a mix, and N treatments consisted of plus or minus inorganic N fertilization. The shoot N contents of vetch and mix cover crops ranged from 100 to 150 kg/ha, whereas N contents of rye were usually <50 kg/ha. In 1994 and 1995, vetch shoot N contents were 150 kg/ha, and corn yields following vetch were not significantly affected by addition of inorganic N fertilizer. In 1996, vetch N contents only equaled 120 kg/ha, and corn yields were significantly increased by addition of inorganic N. Supplemental N was also required to obtain maximum yields following mix and rye cover crops in all years, even though the N contents of vetch and mix cover crops were normally similar. Measurements of corn foliar N and available soil N were in agreement with the yield results. No-tillage did not significantly affect corn yields following vetch. However, no-till corn yields were reduced with rye (1995) and the mix (1995 and 1996) as a result of reduced corn plant population densities. Reliable tillage results were not obtained for 1994. It was concluded that a vetch cover crop could adequately supply N to sweet corn if vetch N content was at least 150 kg/ha. Sweet corn following rye or vetch/rye mix cover crops required additional N for optimal yields. Significant N in the mix cover crop was probably immobilized as the rye component decomposed. No-till sweet corn was grown successfully following vetch, but yields were often reduced with the mix or rye cover crops.
176 Effect of Plastic Rowcover on Watermelon Crop
Authors: Hassan Elattir , Chabi Youness
Published: February 2019

Citrullus vulgaris cv Rocio hybrid F1 was seeded 18 Jan. 1994 and transplanted 1 month later in loam-sandy soil at the experiment station of the Complexe Horticole, 16 km south of Agadir. Watermelon plants grown under perforated plastic rowcover with 800 holes per square meter were compared to the open-field plants. The experiment design used was a randomized block design with two treatments (rowcover and open field) and four repetitions. Rowcover was put at planting and removed 90 days later. Under the rowcover the minimal and maximal temperatures were higher than the ones of the open field by 0.9 to 2.4 and 3 to 6.8 °C, respectively. Soil temperatures at 10-cm depth measured at 7:00 am and 4:00 pm were higher under cover by 1.2 and 2.7 °C, respectively. Early yield of watermelon obtained under perforated plastic rowcover and in open field were 6.55 kg/plant (78.6 t/ha) and 2.45 kg/plant (29.4 t/ha), respectively.
177 A Voluntary Retrofit Program for Open Mix-load Wells in Dade County, Florida
Authors: Lamberts Mary , Nothdurft Judy
Published: February 2019

Southeastern Florida is underlain by the Biscayne Aquifer, an officially designated “drinking water quality aquifer.” This is the sole source of water for the more than 3.5 million residents of metropolitan Miami-Fort Lauderdale. Due to the unique nature of the soils in southern Dade County, Fla., most agricultural wells for both irrigation and mix-load activities have been exempt from casing and capping requirements. Wells associated with U-Pic stands need to be capped if children are allowed in fields. The county's Dept. of Environmental Resources Management (DERM) began a study of mix-load wells in the late 1980s. They concluded that surface materials, including agrichemicals, could drain directly into the aquifer. This was particularly true in vegetable fields because most are on leased land. In the mid 1990s, a program to develop voluntary guidelines to retrofit these mix-load wells was begun. Several growers met with DERM, the Florida Department of Environmental Protection and Extension, to finalize three basic designs. Extension hosted meetings and reviewed the brochure describing the retrofit program. In 1996, one area came under close scrutiny by the U.S. EPA for potential point-source pollution. These growers were made aware of the program and have retrofitted at least 95% of the wells in the most environmentally sensitive area.
178 Differences in Grape Phylloxera-related Grapevine Root Damage in Organically and Conventionally Managed Vineyards in California
Authors: Lotter D.W. , Granett J. , Omer A.D.
Published: February 2019

Secondary infection of roots by fungal pathogens is a primary cause of vine damage in phylloxera-infested grapevines. In summer and fall surveys in 1997 and 1998, grapevine root samples were taken from organically managed vineyards (OMVs) and from conventionally managed vineyards (CMVs), all of which were phylloxera-infested. In both years, root samples from OMVs showed significantly less fungal pathogen-caused root necrosis than samples from CMVs, averaging 9% in OMVs and 31% in CMVs. There was no significant difference in phylloxera populations per 100 g of root between OMVs and CMVs, although there was a trend toward higher populations in CMVs. Soil characteristics, percent organic matter, total nitrogen, nitrate, and percent sand/silt/clay were not significantly different between the two regimes. Cultures of necrotic root tissue showed significantly higher levels of the benefical fungus Trichoderma in OMVs in 1997 but not in 1998, and there were significantly higher levels of the pathogens Fusarium oxysporum and Cylindrocarpon spp. in CMVs in 1998 but not in 1997. Implications for further research and viticulture are discussed.
183 Influence of Cover Crops on Weed Control and Plant Growth in Strawberry (Fragaria × ananassa Duch.)
Authors: Datta Braja B. , William Ray D
Published: February 2019

Fall-planted cover crops killed in spring is practiced in strawberry cultivation in different regions of the North America. These systems have shown significant weed suppression and conservation of soil without significant yield reduction in strawberry. During the establishment season, this study was initiated to assess weed suppression with cover crops (`Wheeler' rye and `Micah' and `Steptoe' barley) along with perlite, an artificial plant medium. Strawberry (`Selva' and `Totem') plant growth and weed biomass were measured during 1995-96 season. Small-seeded summer annual weeds were suppressed in cover crop treatments compared to control treatment. `Micah' barley in growth phase suppressed more than 81% of the total weed biomass compared to control plots with no cover crop in early spring. However, in early summer, cover crop residues failed to suppress different types of weeds 60 days after killing of cereal with herbicide (2% glyphosate). Distinct differences in strawberry plant growth were evident between the cover crop treatments and non-cover crop treatments including `Micah' applied on surface. Strawberry growth was doubled during 10 July to 15 Aug. in both cultivars. `Micah' barley applied on surface produced better growth in both strawberry varieties than the growth in other treatments. `Micah' barley applied on soil surface produced 50% more strawberry shoot biomass may indicate the root competition between cover crops and strawberry.
185 Managing Primocane Growth for Rotatable Cross-arm Trellis
Authors: Takeda Fumiomi , Hummell Ann K.
Published: February 2019

A new trellis system called the “rotatable cross-arm” (RCA) trellis was developed to ease mechanical fruit harvesting of eastern thornless blackberries. The rotation of the cross-arm following bloom 1) positions all the fruit to one side of the trellis in a plane underneath the cross-arm and 2) permits primocanes to be trained to side without the fruit. To maintain productivity, the number of lateral shoots that arise from primocanes must be maximized. In this study, we examined the growth and development of individual primocanes within plants and the number of lateral canes that developed on them to decide which canes should be retained during the growing season. In `Chester Thornless' blackberry, primocanes trained early in the season produced more laterals per cane, had higher percentage of buds forming laterals, and were much larger in diameter than primocanes trained later in the season. Field observations suggested high sink strength and less light competition probably contributed to the increased productivity of early canes. These results indicated that the canes that become trainable early in the season must be retained for the success of the RCA trellis. Conversely, the primocanes that become trainable later in the season do not develop sufficiently and should be removed.
188 Influence of Planting Date on Strawberry Growth and Development in the Low Desert
Authors: Maurer M.A. , Umeda K.
Published: February 2019

A field study was designed to determine the effect of planting date and cultivar on growth and yield of strawberries in the low desert. The study was conducted at the Univ.of Arizona, Citrus Agricultural Center, near Waddell. Treatments included two strawberry cultivars (Camarosa and Chandler) and three planting dates 20 Aug. and 8 and 22 Oct. 1997. There was no significant difference in fruit yield between cultivars. However, fruit number was significantly greater for `Chandler', and, therefore, fruit size was smaller than `Camarosa.' Yield was significantly higher for strawberries planted 20 Aug., with nearly four times the yield compared to the other planting dates. Results of this study suggest summer planting of strawberries in the low desert to produce economically viable yields.
189 Vegetation Management of Lowbush Blueberries
Authors: Percival David C. , Stevens Dianne , Sampson Glen , Patterson Gary , Jensen Klaus
Published: February 2019

The influence of noninvasive, companion crops on lowbush blueberry production was examined at the Nova Scotia Wild Blueberry Inst. in 1998. A randomized complete-block experimental design was used with four replications and a plot size of 10 × 6 m. Treatments consisted of a control (no companion crop), sawdust, creeping red fescue, hard fescue, chewings fescue, sheeps fescue, birdsfoot trefoil (BFT), and redtop. Measurements of companion crop height, dry weight, and density, and lowbush blueberry vegetative and reproductive data were recorded. In addition, the effects of the companion crops on soil stability and weed pressures were measured at the conclusion of the growing season. Overall, the fescues and BFT established well within the blueberry canopy and in bare areas with plant densities ranging from 960 plants/m2 to 3500 plants/m2, plant dry weights of 7.2 to 11.7 mg/plant, and plant heights of 5.4 to 9.5 cm. The use of the companion crops increased yields with yields from the creeping red and hard fescue treatments being 9.0% and 13% greater, respectively, than the control. The creeping red and hard fescue treatments also significantly reduced weed pressures and increased soil stability. Therefore, using companion crops in lowbush blueberry production appears to be a viable management strategy with future research being required on herbicide use, fertility regimes, and harvestability.
192 Controlling Early Growth of Marigold and Tomato Plugs
Authors: Pasian C.C. , Bennett M.A.
Published: February 2019

Some transplanted crops, like tomato and marigolds, tend to stretch very early after germination, especially if grown in low light environments. By the time growers apply growth regulators (PGRs), the stretching of the hypocotyl has already occurred and sprays are ineffective. Seeds of marigold `Bonanza Gold' and tomato `Sun 6108' were soaked for 6, 16, and 24 h in paclobutrazol solutions of 0, 500, and 1000 ppm. After imbibition, seeds were dried for 24 h before sowing in plugs. Sixteen, 26, and 36 days after sowing, seedling height and percent emergence were measured. Increasing concentrations of PGR and time of imbibition produced shorter seedlings. Tomato seedling heights measured 36 days after sowing were 1.9, 1.5, and 1.7 cm when imbibed in water for 6, 16, and 24 h, respectively. When PGR was used at 500 ppm, seedling heights were: 1.4, 1.2, and 1.2 cm, respectively. Similar reductions were observed for marigolds. It was hypothesized that some seeds have coats that are impermeable to PGRs. These impermeable coats might serve as PGR carriers, delivering the chemical into the growing medium of the plug cell. When the root emerges from the seed, it absorbs the growth regulator. These preliminary results indicate that this method of PGR application may be feasible and could benefit plug growers of marigold and other ornamental plant species prone to early stretching (e.g., cosmos).
193 The Effect of Bedding Plant Plug Source on Postplug Production
Authors: Kuehny Jeff S. , Painter Aaron , Branch Patricia C.
Published: February 2019

Plug production has increased the finished quality and uniformity of bedding plants, making them one of the most important greenhouse crops grown. The wide range of cultural practices used by different growers to produce plugs, may influence the efficacy of plant growth regulators applied to the same crop in postplug production. Ten bedding plant species were grown from plugs obtained from two sources using different cultural practices. The plugs were transplanted to jumbo six packs and sprayed with either chlormequat/daminozide tank mix, ancymidol, or paclobutrazol at three concentrations at three times of year. The effect of each plant growth regulator varied by plant species and time of year applied. Source of plug material did have a significant effect on height and time of flowering of finished bedding plants and the use of plant growth regulators did not minimize the differences in height between sources in most cases.
194 Effects of Chemical Growth Retardants on Rooting and Stem Elongation in Propagation of Stachytarpheta spp.
Authors: Schoellhorn Richard K. , Compton A.J.
Published: February 2019

Plants, which move directly from the wild into commercial propagation, without the benefit of extensive breeding and selection, often pose production-oriented problems for growers. Vigorous plant growth, especially during the propagation phase of production is a common problem. The purpose of this work was to determine the degree of efficacy offered by chemical control of stem elongation in propagation of Porter Weed [Stachytarpheta mutabilis, S. mutabilis var. violacea, and S. urticifolia]. Tip cuttings of three Stachytarpheta species were given a 10-s dip in the following treatment solutions: daminozide (2500 and 5000 mg·L-1), daminozide and chlormequat chloride tank mix (2000 mg·L-1 ea.), paclobutrazol (2 and 4 mg·L-1), uniconazole (2 and 4 mg·L-1), distilled water, and undipped controls. Cuttings were then treated with a 0.1% IBA rooting powder and placed under intermittent mist on the propagation bench. After 2 weeks in propagation, cuttings were harvested and shoot elongation, root development, and dry weights were evaluated. The interaction of chemical and species was significant for stem elongation and dry weight; chemical effect on root development was also significant. Paclobutrazol and uniconazole offered greater control of stem elongation than daminozide, daminozide-chlormequat chloride, water, or control treatments.
195 Bird Pepper Growth and Fruiting Response to Pinching and Uniconazole Sprays
Authors: Ramcharan Christopher
Published: February 2019

Preliminary experiments with uniconazole (UNZ) at 5- and 10-ppm sprays on Bird Pepper indicated that UNZ could be used to enhance appearance and improve fruiting of Bird Pepper, but some refinement of UNZ rates had to be made. Another experiment was conducted to determine rates of UNZ needed to maintain a suitable plant size with manual pinching and improve yield and total number of red fruit produced. Best overall effects were on plants single-pinched 4 weeks after sowing and treated with a foliar spray of 4 to 6 ppm UNZ. Higher UNZ levels produced too compact plants in which individual branches had to be staked. More-attractive double-pinched plants may be produced if UNZ application is delayed after the second pinch. Bird pepper can therefore be produced as a dual purpose pot plant by pinching followed by foliar applications of of UNZ preferably at 4 to 6 ppm.
209 Initiating a Statewide Evaluation System for Watermelons
Authors: Brandenberger L. , Baker M. , Bender D. , Dainello F. , Earhart R. , Parsons J. , Roberts R. , Roe N. , Stein L. , Valdez M. , White K. , Wiedenfeld R.
Published: February 2019

During the past several years, watermelon trials have been performed in the state, but not as a coordinated effort. Extensive planning in 1997 led to the establishment of a statewide watermelon trial during the 1998 growing season. The trial was performed in five major production areas of the state including: The Winter Garden (Carrizo Springs); South Plains (Lubbock); East Texas (Overton); Cross Timbers (Stephenville); and the Lower Rio Grande Valley (Weslaco). Twenty seedless and 25 seeded hybrids were evaluated at each location. Drip irrigation with black plastic mulch on free-standing soil beds was used to grow entries in each area trial and yield data was recorded in a similar manner for each site. Results were reported in a statewide extension newsletter. Future plans include a continuation of the trial in the hope that multiple-year data will provide a basis for valid variety recommendations for watermelon producers in all areas of the state.
214 Yield and Quality Response of Carrot (Daucus carota L.) to Simulated Storm Damage
Authors: Bartolo Michael E. , Schweissing Frank C.
Published: February 2019

Parts of Colorado receive more hail than almost any other area in the nation. Severe storms can injure crop tissue and, thus, lower yield and predispose the crop to disease infection. Our study was conducted to determine the yield and quality response of carrot (Daucus carota L.) to simulated storm damage during different periods of plant development. We removed 33% and 67% of the carrot foliage at four dates, spaced 10 days apart, during the middle of the growing season. In 1997 and 1998, 67% defoliation significantly reduced total and marketable yields more than did 33% defoliation. Total yield components, length and diameter, were similarly affected. Defoliation, in general, decreased yield the greatest when it when it occurred at the later stages of development. Carrot foliage continued to develop and grow after all defoliation events. Nonetheless, moderate (33%) and severe (67%) foliage loss reduced marketable yield and yield components of carrots.
219 Food-grade Greenhouses: Development and Implementation of a HACCP Plan for the Production of Controlled Environment Agriculture (CEA) Boston Lettuce
Authors: Langhans Robert W. , Salamanca Mauricio
Published: February 2019

With the primary objective of assuring food safety at the production level, a HACCP (Hazard Analysis and Critical Control Point) plan was developed and implemented in an 8000-ft2 greenhouse producing 1000 heads of lettuce per day in Ithaca, N.Y. The plan was developed following the HACCP principles and application guidelines published by the National Advisory Committee on Microbiological Criteria for Foods (1997). The CEA glass greenhouse uses both artificial high-pressure sodium lamps and a shade curtain for light control. Temperature is controlled via evaporative cooling and water heating. Lettuce plants are grown in a hydroponic pond system and are harvested on day 35 from day of seeding. Known and reasonable risks from chemical, physical, and microbiological hazards were defined during the hazard analysis phase. Critical control points were identified in the maintenance of the pond water, the operation of evaporative coolers, shade curtains, and during harvesting and storage. Appropriate prerequisite programs were implemented before the HACCP plan as a baseline for achieving minimum working conditions. Proper critical limits for some potential hazards were established and monitoring programs set up to control them. Postharvest handling was setup in an adjacent head house that was adapted as a food manufacturing facility according to New York State Dept. of Agriculture and Markets standards. Potential applications will be discussed.