bluuebunny/crossref_metadata_2025 huggingface dataset:
023 Examination of Carriers in Application of Pre-Emergence Herbicides in Container-grown Nursery Stock
Authors: Mathers Hannah
Published: February 2019

Weed growth in container-grown nursery stock is a particularly serious problem. Inexpensive and easily accessible carriers for safe application of concentrated preemergent herbicides have been investigated. Monaco and Hodges (1974) evaluated standard pine bark used in potting media. Coating broadcast fertilizers with preemergents has also been recently examined in agronomic crops (Koscelny and Peeper, 1996; Rabaey and Harvey, 1994). The four objectives of this experiment were: 1) determine the efficacy and duration of weed control of a range of preemergent herbicide-impregnated carriers, applied as a top-dressing. The preemergents to be tested are: Goal, Surflan, Rout, Gallery, Gallery/Surflan, Ronstar and Regal 0; 2) determine the efficacy and duration of weed control of a range of preemergent herbicide-impregnated slow and controlled release fertilizers, applied preplant incorporated in the potting mix; 3) assess the phytotoxicity of the chemical-treated carriers on the ornamental plants evaluated; and 4) determine which weeds were controlled. Of the carriers investigated, bark was the best treatment regardless of pre-emergent used. However, Surflan and Gallery were slightly better than Goal. The effectiveness of the bark in controlling weeds is worth investigating in further studies. A significant species effect with the efficacy data was observed. Euonymus `Emerald Gaiety' was significantly better at competing with the weeds present than the other species evaluated. Top dressing gave significantly fewer weeds, with rated data, vs. incorporation. The effect was most pronounced for Kansel or Fert. plus Ronstar. Osmocote micro-fert. gave less weeds, top-dressed, when weed weights were analyzed. However, using the weed weight data, there were no significant differences whether the carriers were applied top dress or incorporated. Phytotoxicity was not significantly different with incorporation vs. top dressing.
027 Genetic Analysis of Resistance to the Peanut Root-knot Nematode Exhibited by the Capsicum chinense Germplasm Line PA-353
Authors: Fery R.L. , Thies J.A.
Published: February 2019

The peanut root-knot nematode (Meloidogyne arenaria race 1) is potentially a major pest of pepper cultivars belonging to the species Capsicum chinense. Greenhouse tests were conducted to: 1) compare the level of resistance to the peanut root-knot nematode exhibited by the recently released C. chinense germplasm line PA-353 to that exhibited by the C. annuum cv. Carolina Cayenne; 2) to determine the inheritance of the resistance in the C. chinense germplasm line PA-353; and 3) to determine the genetic relationship between the resistance exhibited by the C. chinense germplasm line PA-353 and that exhibited by the C. annuum cv. Carolina Cayenne. The level of resistance exhibited by the C. chinense germplasm line PA-353 was equal to the high level of resistance of the C. annuum cv. Carolina Cayenne. Evaluation of parental, F1, F2, and backcross populations of the cross between the resistant C. chinense germplasm line PA-353 and the susceptible C. chinense accession PA-350 indicated that the resistance in C. chinense is conditioned by a single dominant gene. The F2 population of the interspecific cross between the resistant C. chinense germplasm line PA-353 and the resistant C. annuum cv. Carolina Cayenne did not segregate for resistance, indicating that the dominant resistance gene in C. chinense is likely allelic to or closely linked to a gene conditioning resistance in C. annuum. The availability of a simply inherited source of outstanding resistance makes breeding for peanut root-knot nematode resistance a viable objective in C. chinense breeding programs.
032 Resistance to Papaya Ringspot Virus in Watermelon
Authors: Strange E. Bruton , Wehner Todd C. , Pesic-Van Esbroeck Zvezdana
Published: February 2019

Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] is a major crop in the southern U.S., where the most important virus diseases are papaya ringspot virus (PRSV), watermelon mosaic virus-2, and zucchini yellow mosaic. The most economical control of virus diseases of watermelon is probably through genetic resistance. Watermelon has not been screened extensively for resistance to PRSV. The objective of this research was to develop a suitable method for screening watermelons for resistance to PRSV and then to screen the USDA germplasm collection. To date, we have developed an effective method and have nearly completed the screening. Several of the 1283 accessions have shown resistance to the virus. Methods tests involved 10 isolates of PRSV, several watermelon accessions and multiple inoculation procedures. Seedlings were screened in greenhouse flats with six replications per test. Tests were rated visually on a 0 to 9 scale (0 = no damage, 9 = plant dead), as well as with ELISA to detect the presence of virus. The watermelon germplasm collection was screened in four separate runs of 1283 accessions with `Charleston Gray' as the susceptible check. This research will be useful for those interested in effective screening methods, and sources of resistance for development of improved watermelon cultivars.
033 Characterization of Downy Mildew Resistance in USDA Broccoli Inbreds
Authors: Wang Min , Farnham Mark W.
Published: February 2019

Downy mildew, caused by Peronospora parasitica (Pers. ex Fr.), is one of the most economically important diseases in broccoli (Brassica oleracea L. Italica group). Previous studies reported that resistance to downy mildew in broccoli depends on plant age and that seedling resistance appears to be independent of mature-plant resistance. The objectives of our studies were to evaluate resistance and susceptibility of USDA broccoli inbreds to downy mildew and to investigate the interaction between the host and pathogen at two plant stages with single or double inoculation. Multiple screening tests at both cotyledon and three-expanded leaf stages using 38 entries, including USDA inbreds and commercial hybrids, were conducted in randomized complete-block designs. In these tests, every leaf of each plant was thoroughly sprayed with P. parasitica isolate PP1 at a concentration of 10,000 sporangia per ml at both stages. Ratings for downy mildew reaction phenotype were made at 9 days postinoculation on a 0-9 scale of increasing disease severity. We found significant phenotypic variation to infection among broccoli entries. We observed three general phenotypes: 1) resistance at both stages; 2) susceptible at cotyledon stage combined with resistance at three-expanded leaf stage; and 3) susceptibility at both stages. Additionally, inoculation at the cotyledon stage had no effect on inoculation at the three-expanded leaf stage.
034 Independence of the Reduced Pigment (rp) Gene and the Y and Y2 Loci in Carrot (Daucus carota L.)
Authors: Tozuka Azumi , Breitback N. , Goldman I.L.
Published: February 2019

Five genes, including alleles at Y, Y1 and Y2, and the alleles I and IO, have been implicated in conditioning carrot root color. Various combinations of these alleles can condition white, yellow, and orange xylem and phloem color in carrot roots. The recently discovered reduced pigment gene, designated rp, conditions pale orange xylem and phloem and reduces carotenoid content by 92%. To determine if the rp gene is an allele of a previously described locus or a separate locus involved in pigment biosynthesis, we crossed rprp plants to plants with yellow phloem and yellow xylem (yellow/yellow) and to plants with purple phloem and yellow xylem (purple/yellow). We generated BC1 and F2 progenies for evaluation of segregation data. The expected genotype of plants with yellow xylem was yyY2Y2RPRP and the expected genotype of plants carrying rp was yyy2y2rprp. More than 1900 individual plants were evaluated for root color in 38 matings. In F2 progenies resulting from crosses of rprp × yellow/yellow, segregation data from 19 out of 20 families fit expected 12:3:1 (yellow: orange: rprp) or 15:1 (orange: non-orange) ratios (P < 0.001) indicating independence of the rp gene. In addition, 12 out of 16 families of F2 progenies from the cross between purple/yellow plants and rprp plants fit expected 12:3:1 (yellow: orange: rprp) ratios (P < 0.001) for a 2-gene model. These data support the hypothesis that the rp gene is independent and not linked to Y and Y2 genes.
037 Variability for Processing Quality Traits in Two Recombinant Inbred Populations of Kidney Bean
Authors: Posa M.C. , Kelly J.D. , Hosfield G.L. , Grafton K.C.
Published: February 2019

Two recombinant inbred populations of kidney beans were developed and evaluated for canning quality. One population, composed of 75 recombinant inbred lines (RILs), was from a Montcalm/California Dark Red Kidney 82 cross. The second population, with 73 RILs, was from a Montcalm/California Early Light Red Kidney cross. RILs from both populations were planted in North Dakota in 1996 and Michigan in 1996 and 1997. Beans of each RIL were thermally processed using established procedures. Appearance and degree of splitting of each sample and the check varieties were scored subjectively on a 1-7 scale to represent the minimum and maximum acceptability levels of the traits, respectively. Genotypes and genotype × environment interactions were highly significant based on analyses of variance. In the 75 RIL population, seven lines, based on appearance, consistently appeared in the top 25% in all environments (mean = 4.5; range = 4.0-6.1), and four had consistently high acceptability scores (mean = 4.6; range = 4.0-6.3) for the degree of splitting trait. In the population with 73 RILs, nine lines consistently appeared in the top 25% in all environments based on appearance (mean = 4.6; range = 4.1-5.3). For degree of splitting, nine lines had consistently high acceptability scores (mean = 4.2; range = 3.7-5.1). Appearance and splitting of cooked dry bean are quantitatively inherited traits. The field experiments were useful to obtain RILs for screening to identify molecular markers associated with QTLs. Three primers—OQ11, ON186, and OF5—reported to be useful RAPD markers for processing quality in navy beans are of special interest in the current study.
047 Inheritance of Volatile Oil Constituents in Basil (Ocimum basilicum L.)
Authors: Vieira Roberto F. , Simon James E.
Published: February 2019

To determine the mode of inheritance of citral, linalool, methylchavicol, and methylcinnamate in basil, controlled crosses were made between chemotypes rich in each of these constituents. Four stable Ocimum basilicum populations selected for high methylcinnamate (79%), methylchavicol (95%), linalool (82%), and citral (65%) respectively, served as parents. Crosses were made using chemotypes rich in terpenes (linalool × citral), in phenylpropanoids (methylchavicol × methylcinnamate), and a third that combines chemotypes from both biosynthetic pathways (linalool × methylchavicol). True hybrids were selfed in isolation and one hundred F2 plants were analyzed for their oil composition. The parents, the F1 hybrids and the F2 generation of all plants were evaluated in a field trial under identical environmental conditions. Plants were harvested at full flowering, and dried at 380 °C. Identification of essential oil constituents were confirmed by GC/MS. The F2 segregation data for each major oil constituent trait will be examined by c2 analysis tests. Preliminary results indicate that methylcinnamate segregates in a 3:1 ratio, and is a dominant major gene. In the two crosses using methylcinnamate chemotype as a female parent, the F2 population segregates in 80:22 and 65:28 methylcinnamate:non-methylcinnamate plant types, with P = 0.42 and 0.25 and c2=0.64 and 1.29, respectively. Analysis of the other crosses are being processed, evaluating qualitative and quantitatively the presence or absence of each constituent in their F2 population.
054 Characterization of Malus hupehensis (Tea Crabapple) with DNA Simple Sequence Repeats
Authors: Benson Laura L. , Lamboy Warren F. , Zimmerman Richard H.
Published: February 2019

Simple sequence repeats (SSRs) are highly polymorphic regions of DNA that can be used for the molecular characterization of apple (Malus) germplasm. SSR markers are sufficiently variable to distinguish between individual plants in wild Malus species. In this study, accessions of Malus hupehensis were screened for fragment length variation in PCR amplified simple sequence repeat regions of DNA. The fragment length phenotype produced by five SSR primer pairs showed no variation between two lineages of M. hupehensis collected in the Changjiang (Yangtse) River valley. One lineage was collected by E.H. Wilson in 1908 near the city of Ichang, Hubei Province. The second lineage was collected by cooperators at China's Southwest Agricultural University (SWAU) in 1997 near the city of Chongqing (Chungking). M. hupehensis Plant Introduction No. 588760 from the National Plant Germplasm System lacks provenance, but displays a fragment length phenotype identical to both the Wilson and SWAU lineages. The spread of a clone may be aided by asexual reproduction through seed, which is not uncommon in polyploid apples. Two seedlings each of 15 maternal trees from the SWAU lineage were assayed for ploidy level by flow cytometry. The DNA content per nucleus for all SWAU progeny fell within the range for triploids, 2.19 to 2.68 pg DNA/nucleus. It appears that plant explorers in China separated by almost 90 years have succeeded in sampling a single clonal lineage of M. hupehensis.
061 Novel Sources of Genetic Resistance to Eastern Filbert Blight in Hazelnut
Authors: Lunde C.F. , Mehlenbacher M.S. , Smith D.C.
Published: February 2019

A survey of hazelnut (Corylus avellana L.) genotypes for response to the eastern filbert blight pathogen [Anisogramma anomala (Peck) E. Müller] was performed. Seven varieties were discovered that did not display disease signs or symptoms when subjected to severe inoculation with A. anomala in the greenhouse and assayed for infection. These cultivars are `Closca Molla', `Ratoli', `Yoder #5', `Potomac', `Medium Long', `Grand Traverse' and `Zimmerman'. `Ratoli' and `Closca Molla', both minor varieties from Spain, are superior agronomic types to the resistant cultivar Gasaway, which has been the main resistance source used in the breeding program. Only `Zimmerman' carries the RAPD marker linked to resistance in populations segregating for the `Gasaway' gene. Three populations were created using, `Zimmerman', as the pollen parent in controlled crosses. These populations were inoculated with spores of the pathogen and assayed by indirect ELISA and by observation of canker incidence. Resistant phenotypes make up 84% of the populations, indicating that `Zimmerman' possesses resistance either distinct from or additional to that found in, `Gasaway'. A RAPD marker linked to the resistance gene in crosses with `Gasaway' cosegregates with the resistant phenotype in all three populations (0 cM, 3 cM, 4 cM). Mechanisms to explain the distortion in these populations are discussed. Further studies are required to characterize the mechanism and inheritance resistance in these other clones.
065 Genetic Diversity of the Allegheny Chinkapin (Castanea pumila var. pumila)
Authors: Dane Fenny
Published: February 2019

American species in the genus Castanea are susceptible to chestnut blight, caused by the Asian fungus Cryphonectria parasitica. This disease spread throughout the natural range of the American chestnut and reduced the species from a timber and nut producing tree to an understory shrub. The lesser known member of the genus, the chinkapin, has also been affected by this disease and a conservation plan is needed. Genetic diversity within and between geographic populations of the Allegheny chinkapin was evaluated to provide baseline genetic information pertinent to conservation of the species. Nuts of Allegheny chinkapin trees from populations in Mississippi, Florida, Alabama, Virginia, and Ohio were collected and evaluated for isozyme and RAPD marker polymorphism. The genetic diversity of these populations will be compared with that of Ozark chinkapin and American chestnut populations. Conservation strategies will be discussed.
096 Muscadine Traits Potentially Useful in Breeding
Authors: Gupton C.L.
Published: February 2019

A muscadine vineyard planted at McNeil, Miss., in 1990 included 23 cultivars and a planting in 1992 included nine cultivars. Each entry was evaluated for eight useful traits over 4 years. The regressions of certain traits on others were performed to determine relationships that might be useful in selecting for valuable traits such as phyto-chemicals in seed. Ranges among cultivars for the traits were: harvest date—20 days, yield—33 kg per vine, berry weight—11.2 g, percent dry scar—38, °Brix—5, pH—0.5, seed per berry—1.2 and seed weight—5.5 g. The best relationship was between berry weight and seed weight.
099 Indirect and Direct Regeneration of Kalmia latifolia
Authors: Brand Mark H.
Published: February 2019

To introduce desirable trait genes into Kalmia latifolia, efficient adventitious shoot regeneration methods are needed. Silver Dollar (S$) callus induction and growth in the dark was compared on Woody Plant (WP) medium containing 2,4-dichlorophenoxyacetic acid (2,4-D) (1, 5, 10, 20 μM) or naphthaleneacetic acid (NAA) (1, 10, 20, 40 μM) with and without 5 μM isopentenyladenine (2iP). Both 2,4-D and NAA produced >450 mg of callus from leaf explants in 8 weeks. The addition of 2iP tripled growth for 2,4-D and doubled growth for NAA. Greatest callus growth was obtained on 20-40 μM NAA or 5-20 μM 2,4-D. Shoot regeneration on callus was achieved on WP medium containing 30 μM 2iP or 1 μM thidiazuron (TDZ), but a combination of the two was best, with 68% of dark-grown calli regenerating shoots in 4 weeks. 26% more dark-grown calli regenerated shoots than light-grown calli. The type of auxin (2,4-D or NAA) used to grow the calli did not affect shoot regeneration. For direct shoot regeneration, S$ leaf explants were tested on WP medium containing 5, 15, 30, 45 and 60 μM 2iP. The addition of 1 μM indole-3-butyric acid (IBA) doubled the percentage of leaves that regenerated shoots. 2iP concentrations between 15 and 45 μM supported excellent shoot regeneration, but optimal regeneration (95% of explants, 5.1 shoots/leaf) occurred on 30 μM 2iP+1 μM IBA. Leaf explants of six cultivars were grown on optimal medium with shoot regeneration ranging from 17% to 93% of leaves and 1.8 to 8.2 shoots per leaf, depending on the cultivar.
104 Vegetative Propagation of Spigelia marilandica (Indian Pinks) from Shoot-tip Cuttings
Authors: Foster Susan , Kitto S.L.
Published: February 2019

Spigelia marilandica, an herbaceous perennial native to the temperate eastern United States, has great potential for the sunny garden; however, its availability is limited due to propagation difficulties. The effect of stock plant environmnet on the rooting capability of the cuttings is the primary focus of this research. Shoot-tip cuttings were collected monthly from stock plants maintained under high-intensity sodium lamps providing a 16 hr day/8 hr night photoperiod. Cutting bases were dipped in Hormodin I (1000 IBA), placed in a perlite:peat (4:1) mix, and placed under mist for 8 weeks. Preliminary data indicates that 95.5% of the cuttings rooted with an average of 39 roots per cutting.
105 Propagation of Taxodium mucronatum (Montezuma Cypress)
Authors: St. Hilaire Rolston
Published: February 2019

Indigenous stands of Taxodium mucronatum Ten. are found in North and Central America, but relatively little is known about the propagation of the species. Progeny from one tree in the Mesilla Valley near Las Cruces, N.M., and from two trees in the Gila National Forest, New Mexico, were observed to be relatively cold-hardy. I initiated this research to find the best conditions for asexual and sexual propagation of those three trees. Terminal softwood cuttings were collected on 16 Oct. 1998 from a half-sibling of the Mesilla Valley tree, and from two half-siblings from the trees in the Gila National Forest. Cuttings were treated with two concentrations of IBA and rooted under intermittent mist in the greenhouse for 13 weeks. Cuttings taken from the Mesilla Valley source and from one of the half-siblings from the Gila did not root. The other half-sibling plant from the Gila showed 82% rooting when cuttings were treated with 8 g IBA/kg. Fifty percent of cuttings rooted when they were treated with 3 g IBA/kg. Root number and root length were greatest for cuttings treated with 8 g IBA/kg. Replication over time will determine whether stock plant environment and the time of taking cuttings affect rooting. Strategies that optimize seed germination and seedling development of asexually and sexually propagated material are being evaluated.
125 Substrates and Hydrophylic Polymers Influence Growth of Surfinia
Authors: Jobin P. , Caron J. , Menard C. , Dansereau B.
Published: February 2019

Low water retention in hanging baskets is a constraint in urban floriculture and hydrogel addition is an alternative. However, growth may be reduced with such a product depending on the substrate used. This study was conducted to determine the combined effects of substrate and type of hydrogel on the growth of Surfinia plants produced in hanging baskets. During Spring 1998, three rooted cuttings of Surfinia (Petunia × hybrida `Brilliant Pink') were transplanted into 30-cm hanging baskets. Plants were transplanted into one of the following substrates: 1) Pro-Mix BX, 2) a blend of 4/5 Pro-Mix BX and 1/5 compost, or 3) 1/3 perlite 1/3 vermiculite and 1/3 compost (v/v). These three substrates were amended with two types of hydrogels. The first type, Soil Moist, is an acrylic-acrylamide copolymer and the second type is Aqua-Mend, an acrylic polymer. Plants were grown for 8 weeks under standard irrigation and fertilization practices. Plant growth characteristics, percent dry weight, mineral nutrition, and growth index were determined. Substrate physical properties such as available water content, unsaturated hydraulic conductivity and total porosity were measured. The dry weight and growth index of plants in Pro-Mix BX amended with both types of hydrogels were greater than those plants growing in Pro-Mix BX without hydrogel. Plants growing in substrates 2 and 3 with hydrogels were smaller or similar respectively than those plants growing in substrates without hydrogel. Their effects on physical properties of substrates and plant growth will be discussed.
130 Impact of Fertilizer N Forms on Bedding Plant Development
Authors: Pitchay Dharmalingam S. , Nelson Paul V.
Published: February 2019

It is a common practice in greenhouses to apply fertilizers with a high proportion of N in the NO3 form to achieve short, compact shoots and a moderate (25% or greater) proportion of NH4 or urea for large shoots. However, this practice is not substantiated in the scientific literature. Two experiments were conducted in a greenhouse to assess effects of N form on development. In the first, Petunia hybrida `Mid-night Dreams' was treated with five ratios of NH4:NO3 or urea:NO3 in a factorial arrangement with three concentrations of N (50-low, 100-adequate, and 200-high mg/L at each irrigation). In the second experiment six species of bedding plants were treated in a factorial arrangement of five ratios of NH4:NO3 and two pH levels (acceptably low, 5.4-5.8, and unacceptably low, 4.6-5.2). In all comparisons, height and dry weight of shoots grown with 100% NO3 were equal or larger than the plants grown with combinations of N. There was a general trend for plants to be shorter and lighter at higher NH4 or urea proportions. These results refute the hypothesis that shoot size is under the control of N form. Depth of green foliar color correlated positively with proportion of NH4 or urea. Reputed NH4 toxicity symptoms of chlorosis, necrosis, and curling of older leaves occurred only at adversely low pH levels below 5.2 in experiment 2. Resistance of plants to this disorder under conditions of pH levels in the range of 5.4 to 5.8, high N application rates, and applications of 100% NH4 indicates that bedding plants during commercial production are fairly resistant to this disorder.
138 Evaluation of Soil Amendments for Certified Organic Pepper Production
Authors: Delate Kathleen
Published: February 2019

Organic farming has increased to a $4.2 billion industry in the U.S. and continues to expand ≈20% annually. In Iowa alone, organic acreage for all crops has increased from 13,000 in 1995 to 120,000 in 1998. Organic farmers have requested an unbiased analysis of natural soil amendments/fertilizers and compost products on the market for certified organic vegetable and herb production. In our first-year trials at the ISU Muscatine Island Research Farm in 1998, a total of 1,120 `Hungarian wax' pepper plants were transplanted into rows at 31 × 61-cm spacing. Four replications of seven fertilization treatments were planted within the field. The goal of the fertilization program was to obtain equivalent nitrogen and calcium rates in the organic and conventional systems. Leaf height was not significantly different in plants fertilized with organic compost (poultry litter-based) at 50 and 100 kg/ha N compared with conventional fertilizers (at 100 kg/ha N). All organic and conventional treatments had greater biomass than the organic and conventional controls (no fertilizer), respectively (ANOVA, P = 0.05). First harvest fresh weights were greater in the organic treatments, with the greatest number of peppers and greatest fresh weight in the compost plus Bio-Cal® (a liming industry by-product) treatment. Total pepper fresh weight over the five harvest periods was not significantly different among treatments, demonstrating to organic farmers that comparable yields can be obtained in systems employing alternatives to synthetic nitrogen fertilizer.
140 Influence of Potassium Nutrition on Growth and Sugar Content of Carrot
Authors: Kang Hoon , Lafta Abbas , Lee Chiwon W. , Duysen Murray E. , Cihacek Larry
Published: February 2019

The influence of potassium (K) nutrition on the growth and sugar contents of carrot (Daucus carota L.) cv. Navajo was investigated in a greenhouse study. Seeds were germinated in 15-cm plastic pots (volume1.5 L) containing a peatlite mix (2 parts peat:1 part vermiculite:1 part perlite, v/v). Starting at 6 true-leaf stage (5 weeks from germination), plants were watered with nutrient solutions containing 0, 1, 2, 4, or 8 meq K/L for 10 weeks. While plants receiving no potassium had the lowest biomass yield, there was little or no difference in shoot or root biomass yields between different K concentrations. Root glucose and sucrose contents were the highest when plants grown with 8 meq K/L and 4 meq K/L, respectively, from the nutrient solution. The influence of nutrient solution K concentration on tissue content of K and other macronutrient elements was also determined.
153 The Organic Certification in Western Mexico
Authors: García Arturo , Morentín Xicotencatl , Farias-Larios J.
Published: February 2019

Organic production is a manner of food production whereby people relate to nature to produce healthy food in a sustainable way. Access to the organic food market requires a guarantee that the product complies with the standards and principles established by the moral and legal authorities of organic production. In Latin America, Mexico is the greatest exporter of organic products, mainly coffee. Sales are estimated at nearly 500 million dollars, and certified field surface is 15,000 ha. The objective of this work is to show the certification process of organic production carried at Colima state. The University of Colima Organic Production Certifying Committee (CUCEPRO) is an organic production certification agency, a nonprofit organization, operating since 1993. Furthermore, CUCEPRO promotes organic production, a viable alternative and offer important information on the basic principles of organic production, the procedures which producers need to go through to have their product certified organic. CUCEPRO took part in the determination of the Mexican Quality Control Norms NOM-037-FITO-1995. This agency is constituted by Univ. of Colima teachers and researchers with great expertise on the different areas and processes of organic production. Certification takes between one and 2.5 months depending on distance, kinds of analyses, and seal production and issuing. In the last years CUCEPRO has certified more 3000 hectares of products such as coffee, sesame seed, banana, and mango, as well as honey, compost, and biological pesticides. Certification demand steadily increased due to reliability and confidence on CUCEPRO and to increased acceptance of organic products on the other.
156 Dissemination via the Internet of Information on Pawpaw (Asimina triloba): A New Potential Tree Fruit Crop
Authors: Jones Snake C. , Pomper Kirk W.
Published: February 2019

Kentucky State Univ. (KYSU) emphasizes research on developing alternative, high-value crops and sustainable agriculture methods for use by limited-resource farmers. Since 1990, KYSU has maintained a research program to develop pawpaw into a new high-value tree fruit crop. With its high tolerance for many native pests and diseases, pawpaw shows great potential as a crop for organic and sustainable production. The objectives of KYSU's pawpaw research program include: 1) variety trials; 2) development of new or improved methods of propagation; 3) collection, evaluation, preservation, and dissemination of germplasm; and 4) sharing of information on pawpaw with scientists, commercial growers and marketers, and the general public. To aid in dissemination of information on pawpaw, a web site has been developed (http://www.pawpaw.kysu.edu) that includes information on current and past pawpaw research at KYSU and information on the PawPaw Foundation. On this site, there are a selected bibliography of publications on pawpaw and related species; pawpaw recipes and nutritional information; a guide to buying and growing pawpaws; photos of pawpaw trees, flowers and fruit; and links to other web sites with pawpaw information. In the future, the site will include results from the pawpaw regional variety trials and the database for the National Clonal Germplasm Repository for Asimina spp., located at KYSU. The pawpaw information web site will be an increasingly useful aid in the introduction of pawpaw as a new, potentially high-value, tree fruit crop.
158 Oklahoma Department of Agriculture Inspector Training
Authors: Schnelle Mike , Palmer Scott , Criswell Jim
Published: February 2019

Oklahoma Dept. of Agriculture field inspectors are rarely horticulturists. Yet, they are often expected to provide inspections and suggestions to nursery, greenhouse, and garden center operators. Because of their lack of formal training in ornamental horticulture and related fields, Oklahoma State Univ. extension faculty set out to provide training in horticulture, entomology, and plant pathology-type issues. Results of statewide training workshops will be discussed, including, but not limited to, specific topics such as plant identification and culture, phytotoxicity in the greenhouse and nursery, and worker protection standards. Last, evaluation feedback regarding inspectors' interest for future training workshops will be addressed.
170 Tomato Flowering and Fruiting under Reduced Tillage
Authors: Singh Bharat P. , Whitehead Wayne F.
Published: February 2019

Reduced tillage saves energy and safeguards soil against erosion. While it is widely used for these reasons in producing agronomic crops, it has yet to find acceptance in vegetable cultivation. The main obstacle is the lack of knowledge of the growth and developmental responses of intensively managed vegetable crops to reduced tillage operations. Therefore, this study was performed to determine the effect of different tillage levels on vegetative growth and flowering and fruiting of tomatoes. The following tillage treatments were applied in a randomized complete-block design to a field that was cover cropped with vetch during winter T2 produced maximum vegetative dry weight/plant: 1) fall mold-board + spring no-till (T1), 2) fall mold-board + spring chisel (T2), and 3) fall chisel + spring chisel (T3). The number of flowers/plant were highest in T1, followed by T2 and T3, respectively. There was a 14: 1 ratio between the number of flowers and fruit set. The number of fruit in T1 and T2 were similar, and significantly greater than in T3. The fruit weight of T1 was similar to T2 but significantly greater than T3.
171 Improving Tomato Production with Summer Cover Crops in South Florida
Authors: Bryan Herbert H. , Li Yuncong
Published: February 2019

Cover crops have become an integral part of vegetable production practices in south Florida for weed control and retaining nutrients during the heavy summer rains. A wide variety of plants are used as cover crops in south Florida. Obviously, legumes contribute more nitrogen by fixing N compared to nonlegumes such as sorghum sudan grass, which is a common cover crop in this area. We have evaluated 10 cover crops, where six were legumes in 1997. In 1998, four cover crops (sunnhemp, sorghum sudan, sesbania, and aeschynomene) were evaluated. The sunnhemp (Crotalaria juncea L.) stands out from other tested cover crops for 2 years. Sunnhemp produced 8960 to 11,400 kg dry weight/ha and fixed up to 285 kg N/ha. The evaluation of effects of sunnhemp and other cover crops on the following tomato growth and yield are still in progress and will be discussed.
196 Effects of Paclobutrazol on Growth and Postharvest Characteristics of Miniature Pot Roses
Authors: Grossi J.A.S. , Pemberton H.B. , Lang H.J.
Published: February 2019

Plants of Rosa L. `RUIjef', `RUIdodo', and RUIrosora' were grown using a short-cycle production schedule. Rooted cuttings were established in 11.4-cm pots followed by pinching to start a final forcing period. Paclobutrazol was sprayed at 0, 25, 50, 100, or 200 mg·L-1 when shoots growing after the pinch were 2 to 3 cm long. Plants were harvested when at least two flowers were at stage 2 (showing color, calyx reflexing, no petals reflexed). At harvest, plants were moved to a simulated interior environment at 21 °C with 30 lower case μmol·m-2·s-1 fluorescent light. Plants of `RUIjef' had the most flowers per pot, whereas plants of `RUIdodo' were the shortest and the latest to flower. Plants of `RUIrosora' exhibited the longest shelf-life, but cultivars responded similarly to paclobutrazol treatments. Paclobutrazol treatment at 50 mg·L-1 and above resulted in shorter plants than the control while 25 mg·L-1 and above reduced peduncle length. Days to harvest was unaffected. Plant shelf-life was reduced 2.1 d by 100 or 200 mg·L-1 paclobutrazol treatment in comparison to the control. Longevity of selected individual flowers was reduced 1.4 d after 50 mg·L-1 treatment and by 2.2 d after 100 mg·L-1 treatment. Leaf abscission during the interior evaluation period was significantly reduced by paclobutrazol treatment of 50 mg·L-1 or higher, but leaf abscission overall was less than 10%. Considerations of height control, plant shelf-life and floral longevity should be balanced when using paclobutrazol in miniature pot rose production.
204 Evaluation of Six Ficus Species for Interior Conditions
Authors: Jones L. , Criley R.A.
Published: February 2019

The most popular Ficus for interior conditions is F. benjamina, which has many clonal selections but still drops its foliage too readily. We compared 4- to 5-foot-tall, shade-grown plants of F. nemoralis, F celebensis, F. binnendykii `Alii,' F. oblongifolia (?), and a selection of F. benjamina thought to be `Gulfstream' with F. benjamina `Exotica' that were transferred to the Hamilton Library of the Univ. Hawaii after 14 weeks under 50%, 65%, or 85% Saran shade. During a 9-week evaluation period, new growth, leaf drop, and photosynthesis were determined. Little new growth developed on any plants during the evaluation period in the library. Leaf loss was greatest for F. benjamina `Exotica,' followed by F. celebensis, while the other four species suffered little leaf loss. Leaf loss was greater for plants grown under 50% shade than for 80% shade, while leaf loss from plants produced under 65% shade was either greater or less than 80% shade, depending on species. Leaf loss was greater in low light sites (13.6 μM/m2 per s) than in medium conditions (20 μM/m2 per s) or near windows (29 μM/m2 pers). After the observation period, the plants were to be removed, but library staff asked to retain many plants as they liked the improved atmosphere the plants gave their office and library settings. Most popular for retention were F. binnendykii`Alii,' F. benjamina `Gulfstream,' and F. benjamina `Exotica,' which still looked good despite its high foliage loss initially. The weeping habits of F. nemoralis and F. oblongifolia (?) were not as desirable because of the space they required, although they are performing well after nearly 12 months in the library. F. celebensis, despite its attractive growth habit and foliage, was a disappointment as it lost many leaves and, over 12 months, developed chlorosis and exudation problems.
208 Evaluation of Vegetable Soybean Cultivars from a Range of Maturity Groups for Edamame Production in California
Authors: DeCarli P. , Rivera F. , Brown W. , Gaskell Mark
Published: February 2019

Coastal California vegetable growers produce a wide range of specialty crops for diverse domestic and export markets. Vegetable-type soybean (Glycine max L.) cultivars are grown and consumed fresh in many parts of the world, but particularly in Japan and Asia, where they are known as edamame. Traditional soybean maturity group classification may not be applicable for fresh-market edamame, particularly in mild coastal California growing conditions. We evaluated a total of 55 vegetable soybean cultivars during the 1998 growing season from maturity groups ranging from group 00 to group VI. Replicated field plots were planted on 30-31 May 1998 in San Luis Obispo, Calif. (lat. 35.12°N.). Cultivars from maturity Groups 00 and I began producing on 4 Sept., followed in 7 to 10 days by maturity Group II and III, and by harvest of maturity Group III and IV cultivars on 19 Sept. Harvest of Group IV cultivars continued until 24 Oct. Percent marketable (two- and three-seeded) pods ranged from 86% to 17% among the cultivars. Marketable yields ranged more than 15-fold, with cultivars such as `Sapporo Midori', a group 00 cultivar popular in Japan, producing 348 g/plant, to cultivars such as `Early Hakucho' and `Envy' producing 20 and 5 g plant, respectively.
213 Effect of Plant Density on Plant and Stand Performance in Hydroponically Grown Dry Bean (Phaseolus vulgaris)
Authors: de Villiers David S. , Langhans Robert W.
Published: February 2019

Protein is an important and essential dietary component. Common bean, a major source of vegetable protein in the Americas, was chosen for study in controlled environments with a view to its potential for use in space colonies. Eighteen 0.58-m2 stands of the cranberry type of bean, `Etna', were grown in the greenhouse at plant densities of 7, 15, and 28 plants/m2 in a recirculating ebb-and-flow system. Duration of photoperiod and thermoperiod was 16 h. Day/night temperatures settings were 25/20 °C. Daily light integral was matched across greenhouse sections by means of supplemental lighting; it averaged 17 mol/m2 per day. Crop cycle was 70 days from seed to harvest. At harvest, plants were dismembered so that dry weights of leaf, branch, stem, pod, and bean yields could be separately measured by node of origin. Internode lengths were recorded, and all loose trash recovered. The relationship between yield and plant density followed the form expected. Yield of edible biomass at 7 plants/m2 (284 g/m2) was 88% of that at 28 plants/m2 (324 g/m2), a significant difference. At 15 plants/m2 it was 97%. The trend suggests that further gains (but only very small) in yield can be expected with increased density in this cultivar. Productivity and quantum yield at 28 plants/m2 were 4.69 g/m2 per day and 0.27 g/mol, respectively. The coefficient of variation for plants grown at 28 plants/m2 was three times that of plants grown at 7 plants/m2 (0.88 vs. 0.26). Yield component analysis, harvest index, and plant morphology at the different planting densities are discussed.
217 Plant Height Control by Photoselective Filters
Authors: Cerny Teresa A. , Rajapakse Nihal C. , Oi Ryu
Published: February 2019

A research collaboration between Clemson Univ. and Mitsui Chemicals, Japan, has been established to develop and test photoselective greenhouse covers that can filter out far-red (FR) light and control plant height with minimal use of chemicals. The effects of polymethyl methacylate (PMMA) filters containing FR-intercepting dyes were evaluated on watermelon, pepper, chrysanthemum, and tomato to select an optimum dye concentration. As the dye concentration increased, FR interception increased, photosynthetic photon flux (PPF) decreased, and phytochrome photoequilibrium increased from 0.72 to 0.82. Light transmitted through photoselective filters reduced plant height effectively in all species tested. However, watermelon was the most responsive (50% height reduction) and chrysanthemum was the least responsive (20% height reduction) to filtered light. Tomato and peppers had an intermediate response. In watermelons, total shoot dry weight was reduced over 25% compared to the control plants, with a progressive decrease in shoot weight as the dye concentration increased. The specific stem dry weight was gradually reduced as the dye concentration increased. Specific leaf dry weight was slightly reduced under filters, suggesting that smaller plants as opposed to a reduction in dry matter production primarily caused total dry weight reduction. Light transmitted through filters reduced percentage dry matter accumulation into stems from 27% to 18% and increased dry matter accumulation into leaves from 73% to 82%. Photoselective filters are effective in controlling height similarly to chemical growth regulators. Considering the PAR reduction by increase in dye concentration, a dye concentration that gives a light reduction of 25% or 35% may be optimum for commercial development of photoselective films.
218 Effect of Promalin and GA4/7 on Marketable Asparagus Shoots Harvested
Authors: Johnson Clarence
Published: February 2019

Spraying 9-month-old UC157F1 asparagus plants (Asparagus officinalis L.) with aqueous solutions of GA4/7, BA, and promalin ranging from 0 to 200 ppm in 200-ppm increments and using the mother-stalk method showed that BA continued to produce the most marketable shoots and obtained a higher level of effectveness. GA4/7 showed significance on several days during the harvest period. On the final day, there was no significant difference found for either GA4/7 or promalin. BA produced marketable shoots earlier than promalin, but in the end, both these chemicals were equally effective. Early interaction with GA4/7 × BA resulted in delayed shoot emergence. Promalin is a mixture of GA4/7 and BA.
224 Effect of Accel and Ethephon on Fruit Set and Sugar Content of Three Apple Cultivars
Authors: Ansari Mohammad Ejaz , Matta Frank B.
Published: February 2019

The influence of chemical thinners Accel and ethephon on three apple cultivars Royal Gala, Blushing Gold, and Ultra Gold was investigated. Two experiments were conducted in 1995 and 1996 to determine the effect of Accel at 0, 25, 50, and 75 ppm and ethephon at 0, 100, 200, and 300 ppm on fruit juice SSC, fruit juice sucrose, fruit juice glucose, fruit juice fructose, and fruit set. Accel and ethephon reduced fruit set of `Royal Gala', `Ultra Gold', and `Blushing Golden'. In 1995, chemical fruit thinners Accel and ethephon increased SSC of `Royal Gala' and `Ultra Gold' and did not affect SSC of `Blushing Golden'. In 1996, Accel and ethephon did not effect the SSC of `Royal Gala' and `Blushing Golden'. However, Accel increased SSC of `Ultra Gold'. Accel and ethephon increased sucrose concentration of `Royal Gala', `Ultra Gold', and `Blushing Golden'. Accel increased fruit juice glucose concentration of `Royal Gala', `Ultra Gold', and `Blushing Golden'. Ethephon did not effect fruit juice glucose concentration of `Royal Gala', `Ultra Gold', and `Blushing Golden'. Accel did not effect fruit juice fructose concentration of `Royal Gala'. However, Accel increased fructose levels of `Ultra Gold' and `Blushing Golden' in 1995. Accel did not effect fruit juice fructose concentration of `Blushing Golden' in 1996. Ethephon did not effect fruit juice fructose concentration of `Royal Gala'. Ethephon increased fruit juice fructose concentration of `Ultra Gold'. Ethephon did not effect fruit juice fructose concentration of `Blushing Golden'.
226 Prohexadione-Ca: Growth Regulation and Reduction of Fire Blight Incidence in Pears, cv. `Abate Fetel'
Authors: Costa G. , Andreotti C. , Bucchi F. , Sabatini E. , Bazzi C. , Malaguti S. , Rademacher W.
Published: February 2019

As in other countries, pear production in Italy requires an efficient control of excessive shoot growth. Chlormequat chloride, the only available plant growth regulator, does not necessarily represent the ideal solution because it requires high dosages, thus posing the risk of residues in fruit. Fire blight, which has invaded Italy in at the beginning of 1990, is of great concern because `Abate Fetel', one of the predominant cultivars, is highly susceptible and no preparations for control are currently available. To evaluate solutions for both aspects, prohexadione-Ca (BAS 125 11 W) has been tested on pears under growth chamber and orchard conditions. In each case, reductions of shoot growth and, if present, lowered incidences of fire blight could be achieved. Six-year-old trees of `Abate Fetel', located in an area with high fire-blight infestation pressure, were sprayed with prohexadione-Ca four times each at either 50 or 100 ppm of active ingredient at a new shoot length of 6, 12, 33, and 45 cm. The resulting final shoot length was 96% and 75%, respectively, of the control, whereas an average of 15 fire blight incidences could be found in the controls. This number was reduced to 8 and 4, respectively, in the treated trees. Fruit yield and quality was not affected.
233 Effects of Photoperiod during Transplant Production under Artificial Lighting Conditions on Floral Development and Bolting of Spinacia oleracea L.
Authors: Kim Hyeon-Hye , Chun Changhoo , Kozai Toyoki , Fuse Junya
Published: February 2019

Spinach (Spinacia oleracea L.) was chosen to demonstrate that value-added transplant can be relatively easily produced under artificial light in a closed system. Transplant production under artificial light was divided into three periods, and the photoperiod during each period was varied. It was found that the rate of floral development could be controlled by photoperiod treatments, although floral initiation itself could not be manipulated. Short photoperiod treatments retarded floral development and stem elongation. This occurred even when the transplants were transferred for transplanting to natural conditions with long days and high temperatures. In conclusion, by providing the short photoperiod during the transplant production process, marketable plants with negligible bolting can be produced under natural long-day conditions. Moreover, the production cost per transplant in summer could be reduced by using a combination of natural and artificial lighting during the transplant production process. These results open the possibility to produce value-added transplants of different species under artificial lighting conditions and control their floral development and/or stem elongation for a timely and profitable harvest.