2004 Annual Report
1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? What does it matter?
New and improved pest (disease and insect) control, cultural practices, and management techniques which increase yields and net income, minimize production losses, improve crop quality, and conserve use of natural resources are needed for ornamental and vegetable crops adapted to the Gulf Coast region. We will develop new and improved plant germplasm, methods of pest control, planting systems, irrigation, and crop production management strategies for ornamental and vegetable crops adapted to the Gulf Coast region. We will also determine factors that regulate plant disease, growth characteristics, and tolerance to environmental stress in ornamentals and vegetable crops. The plant production segment of the ornamental industry in the Gulf Coast region is a growing and valuable agricultural commodity group with total wholesale values of $184,885,000 in 2000. Our work will help increase the value of this commodity.
2.List the milestones (indicators of progress) from your Project Plan.
Objective 1. Disease control for ornamental plant production in the Gulf Coast region.
Objective 1.1. Disinfestant efficacy in irrigation water and on substrates.
Objective 1.2. Spray strategies for use of disinfestants on plants.
Objective 1.3. Epidemiology and control of Rhizoctonia web blight.
Objective 1.4. Inoculum sources and latency of camellia twig blight.
Objective 2. Develop strategies to control insect pests of ornamental plants in production nurseries in the Gulf Coast region.
Objective 2.1. Develop strategies to control insect pests of azaleas using cultural and biological control techniques.
Objective 2.1.1. Develop cultural control methods by determining resistance mechanisms of azaleas to the azalea lace bug, Stephanitis pyrioides.
Objective 2.1.2. Develop cultural control methods by determining the effectiveness of natural enemies against the azalea lace bug.
Objective 2.1.3. Study the biology of the strawberry rootworm, Paria fragariae, a pest of container grown azaleas in production nurseries.
Objective 2.2. Determine the seasonal development of arthropods causing economic losses to woody ornamentals in the Gulf Coast region.
Objective 3. Genetic improvement of ornamental plant production in the Gulf Coast region.
Objective 3.1. Develop rust resistant daylily germplasm.
Objective 3.2. Develop improved forms of Leucothoe and Pieris (spp.).
Objective 3.3. Develop improved forms of flowering dogwood.
'Chlorine dioxide (ClO2) rates in water' and 'disinfestant rates on substrates' (objective 1.1) and 'toxicity on ornamental plants' (objective 1.2) were published during the last 12 months. The study 'plant spacing and relative humidity' on Rhizoctonia was completed and will be submitted into ARIS shortly (objective 1.3).
Field tests were begun for host plant resistance of azaleas to lace bugs (objective 2.1.1). A molecular assay was developed to determine which predators are feeding on lace bugs (objective 2.1.2). The biology of the strawberry rootworm was examined including overwintering preference and the number of generations per year (objective 2.1.3). The seasonal development of the Nantucket pine tip moth was determined (objective 2.2).
Genetic improvement of ornamental germplasm in the Gulf Coast area was expanded to include crape myrtle, alstroemeria, hydrangea, azalea, hibiscus, holly, and ginger. The genome size for crape myrtles was determined and a breeding program established. Two diploid alstroemeria cultivars and two daylily cultivars have been converted into tetraploid materials using a new conversion technique (objective 3.1). These tetraploid materials will be incorporated into our breeding program. No progress was made to develop improved forms of Leucothoe and Pieris due to space constraints in the greenhouse (objective 3.2). The genome size for dogwood was determined by flow cytometry to accelerate the molecular mapping and breeding for improved forms (objective 3.3).
Control approaches for foliar applications of hydrogen dioxide will be completed for several foliar diseases of annual and perennial ornamental plants (objective 1.2). Using the assay developed in 2004, seasonal overwintering and active sources of Rhizoctonia inoculum will be identified (objective 1.3). A two year study on how weather affects the time from infection until symptoms of Camellia twig blight appear will be completed (objective 1.4).
The mechanism of resistance in azaleas to lace bugs will be determined (objective 3.2) by observations of feeding behavior in the laboratory and field (objective 3.2). Potential predators of azalea lace bugs will be examined by DNA analysis of their gut contents to quantify predation (objective 2.1.2). Pesticides to control the larval stages of the strawberry rootworm will be evaluated to improve recommendations to growers (objective 2.1.3).
Azalea and holly germplasm will be screened to establish breeding programs. Azalea populations will be generated and screened to determine the genetic basis of lace bug resistance (objective 3). A multi-state experiment to screen hollies for resistance to Thielaviopsis root rot will be initiated (objective 3). Ornamental ginger species will be evaluated for production along the Gulf Coast (objective 3).
Molecular markers for crape myrtle and hydrangea will be established. Hydrangea markers will be used to verify hybrids produced by Dr. Sandy Reed at the National Arboretum (objective 3). Crape myrtle markers will be used for to determine the genetic basis for flea beetle resistance, leaf spot resistance, and powdery mildew resistance (objective 3). Crape myrtle breeding for superior flower qualities will continue. Studies to produce triploid crape myrtles that are sterile and continuously bloom throughout the growing season will also be started.
The genetic diversity and pathogenicity of daylily rust isolates from around the world will be examined (objective 3.1). The genetic basis for daylily rust resistance will be determined by comparing second generation plants to parental material. In addition, resistant diploid daylily varieties will be treated with chemicals to obtain tetraploids which can be incorporated in our breeding program or released to growers. Dogwood hybrids currently under observation will be evaluated for commercial potential (objective 3.3).
Objective 4. Horticultural Milestones (new objective)
Research will focus on newly emerging weed problems in the southeastern United States. There are currently no herbicides labeled for ornamental crop use in enclosed production structures. Weed control strategies including non-chemical barriers and cultural practices will be evaluated in both enclosed structures and field containers.
Current labor practices in the nursery industry will be analyzed with the ultimate goal of developing mechanized plant handling systems. Prototype equipment will be evaluated in various nursery production settings.
A study about how nursery conditions, such as temperature and soiled surfaces, and application methods affect disinfestant rates will be completed (objective 1.1). A two year study modeling the influence of weather on development of Rhizoctonia web blight will be completed (objective 1.3).
Biological control of the azalea lace bug will be evaluated using predators and parasitoids (objective 2.1.2). Monitoring tools for strawberry rootworm and metallic flea beetle will be evaluated (objective 2.1.3). New cultivars of crape myrtle and hibiscus will be screened for pest resistance (objective 2.2).
A woody ornamental germplasm collection will be established in Poplarville, MS (objective 3). Hollies resistant to root rot will be selected for breeding. Crape myrtle linkage mapping will focus on genes for flea beetle resistance, powdery mildew resistance, and leaf spot resistance. Hydrangea markers will be used to uncover the genetic basis for reblooming in the Endless Summer series. Ginger and hibiscus varieties will be studied for their tissue culture/transformation potential and an embryo rescue method will be developed for hibiscus hybrids (objective 3).
Daylily breeding will concentrate on discovering the genetic basis for resistance to daylily rust (objective 3.1). Dogwood seedlings from wild populations that are resistant to powdery mildew and/or spot anthracnose will be incorporated into the marker-assisted breeding program at University of Tennessee (objective 3.3).
Objective 4: Horticultural Milestones
Research will continue to focus on weed control issues in container production and the development of new mechanized equipment for handling container plants in the nursery.
A decision-based integrated approach to controlling disease in rooting-mist beds will be completed (objective 1.1). A nursery sanitation study to minimize Rhizoctonia inoculum sources will be completed (objective 1.3). A fungicide timing study to control Rhizoctonia web blight using the weather-based model developed in 2006 will be completed (objective 1.3). A study evaluating seasonal production of spores that cause infection associated with camellia twig blight and how select cultural practices impact spore production will be completed (objective 1.4).
New cultivars of azaleas, crape myrtles, and hibiscus will be screened for insect pest resistance (objectives 2.1 and 2.2). Control of azalea lace bug by parasitoids, predators, and combinations will be compared (objective 2.1.2). Tools for monitoring strawberry rootworm and metallic flea beetle will be provided to growers.
Molecular markers associated with daylily rust resistance genes will be established in an effort to introduce resistance into commercially important varieties (objective 3.1). Marker-assisted breeding of hydrangea and crape myrtle will continue with an emphasis on flower color and growth habit. Transformation systems will be developed for several herbaceous plants including daylily, alstroemeria, ginger, and hibiscus.
Heat tolerant alstroemeria will be converted into tetraploids to improve ornamental characteristics (objective 3). Root rot resistant hollies from our breeding program will be evaluated as potential replacements for susceptible Japanese hollies currently in production. Hybrid azaleas from our breeding program will be evaluated for combinations of economically important traits.
Objective 4: Horticultural Milestones
Research will continue to focus on weed control issues in container production and the development of new mechanized equipment for handling container plants in the nursery.
4.What were the most significant accomplishments this past year?
Cooperative Extension literature recommends producers space container-grown azaleas so air flow will minimize humidity thus decrease the severity of Rhizoctonia web blight. Dr. Copes determined that wider plant spacing increased evaporation and decreased temperature, but humidity and leaf wetness was not affected enough to decrease disease severity. This knowledge supports the use of narrower spacing increasing production and revenues.
B. Other significant accomplishment(s), if any.
Dr. Rinehart established an automated assay for the detection of azalea lace bugs (Stephanitis pyrioides). In collaboration with Dr. Boyd, this assay was shown useful for detecting lace bug DNA in the guts of predators.
Drs. Rinehart and Cheatham established the genome size for dogwood using modified flow cytometry techniques. This work was done in collaboration with the molecular marker-based breeding program at the University of Tennessee. Dr. Rinehart also determined the genome size for crape myrtles, initiating a molecular marker-based breeding program in collaboration with Dr. Pounders in Poplarville, MS.
Drs. Rinehart and Copes evaluated the genetic diversity of Rhizoctonia pathogens. They collected and analyzed DNA from hundreds of samples from two nurseries to determine the fungal strain that is most prevelant and most harmful to nursery grown plants, especially azaleas.
Twelve hibiscus cultivars were evaluated by Drs. Boyd and Cheatham to determine their resistance to hibiscus sawfly (Atomocera decepta). They found that three species of hibiscus (H. acetosella, H. aculeatus, and H. grandiflora) were resistant to sawfly. A breeding program was established to develop hibiscus cultivars that are resistant to sawfly and have other favorable characteristics.
Drs. Sakhanokho and Cheatham determined a protocol for converting diploid daylilies to tetraploid. This new technique is useful to breeders seeking to release plants with enhanced ornamental traits. Converted daylilies have been incorporated into our breeding program.
C. Significant activities that support special target populations.
Daylily plants have been inflicted with a recently imported rust disease. Scientists in multiple states responded with concentrated research efforts but a non-uniform inoculation rate has hampered success. The influence of placement, application method, and suspension media on infection by daylily rust (Puccinia hemerocallidis) was tested in the laboratories and greenhouses of Drs. Cheatham and Copes at the USDA-ARS Small Fruit Research Station in Poplarville, MS. Spores suspended in oil-based media provided more consistant levels of infections when compared to water based carriers. These results are used by scientists doing research on daylily rust infection and resistance.
5.Describe the major accomplishments over the life of the project, including their predicted or actual impact.
Dose guidelines were developed to treat irrigation water with chlorine dioxide. Chlorine dioxide is currently not used by the ornamental plant industry, however it is increasingly used to treat drinking water (objective 1.1).
Plant sensitivity to hydrogen dioxide was established and research is ongoing to test disease control efficacy. Growers use hydrogen dioxide despite limited documentation of its efficacy (objective 1.2).
A molecular technique was developed to determine the major predators of azalea lace bugs (objective 2.1). Chemical recommendations for control of adult strawberry rootworm were developed (objective 2.1.3). Our evaluation of lace bug resistant azaleas was used as the basis for a new azalea breeding program (objective 2.1).
6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
Chlorine dioxide rates for treating irrigation water, plant sensitivities to chlorine and hydrogen dioxides, and rates of disinfestants labeled to treat plant production surfaces were presented to scientists and industry. Companies are expanding the market for chlorine dioxide because of its high potential for irrigation water treatment. Chlorine and hydrogen dioxides are fairly new products to the ornamental industry, which is the reason plant sensitivity data is so critical for understanding the risk for potential crop damage in a wide variety of ornamental plants. While use-patterns of surface disinfestants are established, this research showed that past rates were not always effective and new standards were proposed.
Chemical control measures for strawberry root worm have been provided to containerized-azalea growers from work conducted by Chazz Hesselein of Auburn University and Dr. Boyd. Crape myrtle cultivars that are resistant to the metallic flea beetle (Altica spp.) were determined by Drs. Boyd and Pounders and by Gretchen Pettis and Dr. Kris Braman of Univ. of Georgia. The list of cultivars is available to growers through two publications, one in the popular press and one in a scientific journal. The growers are being advised to separate the resistant cultivars from the susceptible ones to reduce the amount of pesticides used for flea beetle control.
Dr. Rinehart developed a software program that analyzes data from automated capillary sequencers and formats the output for genetic investigation. This work was published and distributed by field specialists. The software offers significant advantages over current methodologies and is easily modified to fit individual geneticist's needs.
7.List your most important publications in the popular press and presentations to organizations and articles written about your work.
Boyd, D.W., Jr. January 29-31, 2004. Scouting for insects and mites in the urban landscape. The Gulf States Horticultural Expo, Mobile, AL.
Boyd, D.W., Jr., Wheeler, A. G., Jr. 2004. The twobanded Japanese weevil, Pseudocneorhinus bifasciatus (Roelofs) (Coleoptera: Curculionidae): Southeastern U. S. distribution of an adventive pest of ornamental shrubs. 49th Annual Southern Nursery Association Research Conference, Atlanta, GA.
Boyd, D.W., Jr., Cheatham, C.L. October 02, 2003. Evaluation of 12 Hibisucus spp. for Tolerance to the Hibiscus Sawfly Atomocera decepta Rohwer. 31st Annual Horticulture Field Day, Mississippi State University, Poplarville, MS.
Boyd, D.W., Jr., Hesselein, C.P. October 21, 2003. Strawberry Rootworm Biology and Sampling on Azaleas. Auburn University's Mobile Research Center Horticulture Field Day, Mobile Ornamental Horticulture Research Center, Mobile, AL.
Boyd, D.W., Jr., Hesselein, C.P. October 02, 2003. Strawberry Rootworm Biology, Control, and Sampling on Azaleas. 31st Annual Horticulture Field Day, Mississippi State University, Poplarville, MS.
Boyd, D.W., Jr., Hesselein, C.P. 2004. A season's worth of sampling: what we've learned about the strawberry rootworm in containerized azalea production. Turf and Ornamental Symposium, 78th Annual Meeting of the Southeastern Branch, Entomological Society of America. Charleston, SC.
Boyd, D.W., Jr., Hesselein, C.P. 2004. Biology of the strawberry rootworm, Paria fragariae (Coleoptera: Chrysomelidae), in containerized azaleas. 49th Annual Southern Nursery Association Research Conference, Atlanta, GA.
Boyd, D.W., Jr., Pounders, C. October 21, 2003. Crape Myrtle Cultivars Vary in their Susceptibility to the Metallic Flea Beetle. Auburn University's Mobile Research Center Horticulture Field Day, Mobile Ornamental Horticulture Research Center, Mobile, AL.
Boyd, D.W., Jr., Pounders, C. October 02, 2003. Crape Myrtle Cultivars Vary in their Susceptibility to the Metallic Flea Beetle. 31st Annual Horticulture Field Day, Mississippi State University, Poplarville, MS.
Boyd, Jr., D.W., Cheatham, C.L. October 02, 2003. Evaluation of 12 Hibiscus spp. for Tolerance to the Hibiscus Sawfly Atomacera decepta Rohwer. 31st Annual Horticulture Field Day, , Mississippi State University, Poplarville, MS.
Cheatham, C.L., Boyd, D.W., Jr. 2004. Evaluation of twelve species of hibiscus for resistance to the hibiscus sawfly, Atomacera decepta Rowher (Hymenoptera: Argidae). Turf and Ornamental Symposium, 78th Annual Meeting of the Southeastern Branch, Entomological Society of America. Charleston, SC.
Cheatham, C.L. Boyd, C.W., Jr. 2004. Tolerance of selected hibiscus genotypes to the hibiscus sawfly. 49th Annual Southern Nursery Association Research Conference, Atlanta, GA.
Cheatham, C.L. October 02, 2003. Understanding Rust (Puccinia hemerocallidis) Resistance in Daylilies. 31st Annual Horticulture Field Day, Mississippi State University, Poplarville, MS.
Cheatham, C.L., Copes, W.E. August 11-12, 2004. Inoculation efficacy of the medium used for suspension of Puccinia hemerocallidis urediniospores. 49th Annual SNA Research Conference, Atlanta, GA.
Copes, W.E. September 12, 2003. Camellia twig bight. Presentation. Gulf Coast Camellia Society Meeting, Mobile, AL.
Copes, W.E. October 02, 2003. Camellia twig blight: incubation and latency periods. Poster, oral presentation, and proceedings. 30th Annual Horticulture Field Day, Poplarville, MS.
Copes, W.E. October 2, 2003. Rhizoctonia aerial blight in container-grown azaleas. Poster, oral presentation, and proceedings. 30th Annual Horticulture Field Day, Poplarville, MS.
Copes, W.E. February 17-19, 2004. Disinfestants - preventing movement on materials and seeds. Presentation. Mississippi Association of Plant Pathologists and Nematologist Conference, Greenville, MS.
Copes, W.E. August 1-14, 2004. Dose-curve response of disinfestants due to substrates. Presentation. American Phytopathological Society Annual Meeting, Anaheim, CA
Copes, W.E. January 28-30, 2004. Rhizoctonia web blight in container production systems. Presentation. Gulf Coast Horticultural Expo, Mobile, AL.
Fain, G.B., Paridon, K.L. 2004. Production of bareroot Ophiopogon japonicus using calcined clay as a growth substrate. Southern Nursery Association Research Conference, Atlanta, GA.
Hesselein, C.P., Boyd, D.W., Jr. 2004. Insecticide efficacy trials for control of the strawberry rootworm Paria fragariae Wilcox (Coleoptera: Chrysomelidae). Turf and Ornamental Symposium, 78th Annual Meeting of the Southeastern Branch, Entomological Society of America. Charleston, SC.
Hesselein, C.P. Boyd, D.W.,Jr. 2004. Insecticide efficacy trials for control of the strawberry rootworm, Paria fragariae Wilcox (Coleoptera: Chrysomelidae). 49th Annual Southern Nursery Association Research Conference, Atlanta, GA.
Knight, P.R., Coker, C.H., Fain, G.B. 2004. Consumer preferences for edible daylilies. Southern Nursery Association Research Conference, Atlanta, GA.
Posadas, B, Coker, C.H., Fain, G.B., Knight, P.R., Coker, R. 2004. Consumer survey of chrysanthemum cultivars. Southern Nursery Association Research Conference, Atlanta, GA.
Posadas, B., Knight, P.R., Coker, C.H., Fain, G.B., Veal, D., Coker, R. 2004. Socioeconomic Survey of Nursery Automation. Southern Nursery Association Research Conference, Atlanta, GA.
Rinehart, T. October 2, 2003. What can molecular genetics do for ornamental plant research? 31st Annual Horticultural Field Day, Mississippi State University, Poplarville, MS.
Rinehart, T. 2003. What can molecular genetics do for ornamental plant research? Proceedings of the 31st Annual Horticultural Field Day, Mississippi State University, pp 15.
Rinehart, T. Reed, S. October 2, 2003. Genetic diversity in Hydrangea. 31st Annual Horticultural Field Day, Mississippi State University, Poplarville, MS.
Rinehart, T., Reed, R. 2003. Genetic diversity in Hydrangea. Proceedings of the 31st Annual Horticultural Field Day, Mississippi State University, pp 13.
Sakhanokho, H.F., Ozias-Akins,P., May, L., Chee, P. November 10-14, 2002. A non-antibiotic approach to cotton transformation using GFP for selectable marker. 2002. ASA Meeting, Indianapolis, Indiana.
Sakhanokho, H.F., Copes, W.E., Nyochembeng, L.M., Kelley, R.Y. June 4, 2004. Molecular approaches to control Puccinia hemerocallidis on daylily. Biotechnology Symposium. Alabama A&M University, Normal, Alabama.
Sakhanokho, H.F, Cheatham, C.L., Pounders, C.T. October 02, 2003. Chromosome doubling via injection of colchicine in BA-pretreated daylily. 31st Annual Horticulture Field Day, Mississippi State University, Poplarville, MS.
Sakhanokho, H.F., Ozias-Akins, P., May, O.L., Lewis, K.J., Vickers, J., Chee, P.W. 2003. Putrescine Improves Somatic Embryogenesis and Plant Regeneration in Select Cotton (Gossypium hirsutum L.) Genotypes. 2003 ASA-CSSA-SSSA Annual Meeting, Denver, CO, USA.
Copes, W.E., Hendrix, F.F. 2004. Effect of temperature on sporulation of botryosphaeria dothidea, b. obtusa, and b. rhodina. Plant Disease. 88:292-296.
Copes, W.E. 2004. Dose curves of disinfestants applied to plant production surfaces for control of Botrytis cinerea. Plant Disease. 88:509-515
Copes, W.E., Hendrix, F.F. 2004. Temperature effect on sporulation of botryosphaeria dothidea, b. obtusa, and b. rhodina. Phytopathology. 93:S17
Copes, W.E., Chastagner, G.A., Hummel, R.L. 2003. Toxicity responses of herbaceous and woody ornamental plants to chlorine and hydrogen dioxides. Plant Health Progress. dol:1094/PHP-2003-0311-01-RS.
Copes, W.E., Chastaganer, G.A., Hummel, R.L. 2004. Activity of chlorine dioxide in a solution of ions and pH against Thielariopsis basicola and Fusarium oxysporum.. Plant Disease. 88:188-194.
Hesselein, Charles P. and Boyd, David W. Jr. 2003. Srawberry Rootworm Biology and Control. SNA Research Conference, vol.48, pp. 174-176.
Kanga, L.H., Jones, W.A., Humber, R.A., Boyd, Jr., D.W. 2004. Fungal pathogens of the glassy-winged sharpshooter, Homalodisca coagulata (Say) (Homoptera: Cicadellidae). Florida Entomologist. 87:225-228.
Pettis, G.V., Boyd Jr, D.W., Braman, K., Pounders, C. 2004. Potential resistance of crape myrtle cultivars to flea beetle (coleoptera:chrysomelidae)and japanese bettle (coleoptera:scarabaeidae)damage. Journal of Economic Entomology. 97: 981-992
Sakhanokho, H.F., Cheatham, C.L., Pounders Jr, C.T. 2004. Chromosome doubling via injection of colchicine in ba-pretreated daylilly (hemerocallis spp.). Meeting Abstract. March: 48-51
Rinehart, T.A. 2004. Aflp analysis using genemapper software and an excel macro that aligns and converts output to binary. Biotechniques. vol.37(2)pp. 186-188
Sakhanokho, H.F., Copes, W.E., Nyochembeng, L.M., Kelley, R.Y. 2004. Molecular approaches to control puccinia hemerocallidis on daylily. Meeting Abstract. Biotechnology Symposium. pp.18
Boyd, D. W., and D.R. Alverson. 2003. Predation of aphids on caged oak (Quercus sp.) saplings in a greenhouse by Deraeocoris nebulosus (Hemiptera:Miridae).J. Agric. Urban Entomol.20(2):55-58.
Boyd Jr, D.W., Alverson, D.R. 2004. Effects of temperature and water source on deraeocoris nebulosus (uhler) (hemiptera: miridae), a predacious plant bug. Journal of Entomological Sciences. 39: 202-213
Sakhanokho, H.F., Zipf, A., Rajasekaran, K., Saha, S., Sharma, G.C., Chee, P.W. 2004. Somatic embryo initiation and germination in diploid cotton (Gossypium arboreum L.). In Vitro Cellular and Developmental Biology-Plant. 40:177-181.