Location: Southern Horticultural Research2010 Annual Report
1a. Objectives (from AD-416)
The objectives are to develop new and improved crop production practices and disease and insect control practices for ornamental, small fruit and other horticultural crops adapted to the U.S. Gulf Coast region. The developed management techniques are needed to minimize production losses and improve crop quality and yield for the purpose of increasing net income.
1b. Approach (from AD-416)
Identify and evaluate nutritional and cultural requirements, non-Apis pollination efficiency, insect pest problems, and plant disease problems to improve orchard establishment, human health benefit, crop yield, and post-harvest quality of fruit crops. Management techniques to be evaluated include planting systems, irrigation systems, fertilizer selection and timing, non-Apis bee colony establishment, suitability of bio-control organisms, pesticide selection and timing, cultivar selection, fruit handling, and post-harvest storage conditions. Identify and evaluate different organic substrates, insect pest problems, and plant disease problems to improve production options and crop quality of ornamental plants. Management techniques to be evaluated include irrigation and nutritional requirements of plants grown in different organic substrates, suitability of bio-control organisms, cultivar selection, pesticide selection and timing, pesticide application technology, disinfestant selection, and sanitation practices.
3. Progress Report
Progress in small fruit physiology research involved identification of nutraceutical components of barely ripe, fully ripe and over ripe berries. Field fertigation studies were established and fertigation begun. Progress in small fruit entomology research included testing the efficacy of three parasitic wasp species to kill blueberry gall midge larvae. Midge larvae populations were reduced by as much as 90%, a mortality rate comparable to that caused by conventional insecticides. Geranium rose oil, a new and very potent source of biological insecticides, had a lethal potency calculated to be 10 times that of Malathion at the same concentration. Two plant growth regulators (Gibberellic acid and Coconut oil), the latter’s effect being accidentally discovered, increased blueberry fruit set by 40 to 100% and could be used to save berry crops experiencing adverse growing conditions. Progress in small fruit plant pathology research included identification of Phytophthora cinnamomi isolates from soil in blueberry fields, a method to screen blueberry resistance to Phytophthora root rot, establishment of blueberry cultivars in a Phytophthora infested field, nitrogen fertilizer effects on muscadine diseases, bumble bee delivery of fungicides and biological agents to reduce blueberry flower blight, screening strawberry germplasm for resistance markers to anthracnose; and establishment of blackberry cultivars to evaluate rosette and orange rust tolerance and to determine incidence and severity of virus diseases. Progress in ornamental horticulture research included demonstrating the versatility of wood-based substrates for crop production. In a fertilizer study, growth of tree and ornamental ginger species was measured in traditional and wood-based substrates. In propagation studies, root growth of five herbaceous and woody perennials was evaluated in whole pine tree (WPT) and pine bark substrates. In the later study, less root development resulted in the WPT substrate. Additional experiments were initiated to identify possible phytotoxicity in WPT substrates. Progress in ornamental plant entomology research involved testing a durable, reusable and illuminated trapping station to efficiently monitor key pest species of moths and strawberry rootworm beetles in nurseries. Progress in ornamental plant pathology research promotes development of an integrated strategy. Scouting protocol is being tested with known temperature and moisture values to determine the early stages of azalea blight development most response to fungicide treatment in nurseries. Research has shown azalea stems used for propagation can be submersed in hot water (122°C) for 20 minutes to eliminate the fungus, Rhizoctonia, without harming plant stems. DNA primers are being tested for specificity to Rhizoctonia AG-P. DNA primers and pathogen culturing will be used to monitor pathogen distribution in the nursery so controls can be developed to prevent spread to clean plants.
5. Significant Activities that Support Special Target Populations
Blueberry and muscadine grape plants were donated to the Jackson Public School District for gardens inspired by President Obama. Jackson Public school children will grow, harvest and eat fresh blueberries and muscadine grapes planted at the JPS Environmental Learning Center.
Marshall, D.A., Spiers, J.M., Curry, K.J. 2009. Water Uptake Threshold of Rabbiteye (Vaccunium ashei) Blueberries and its Influence on Fruit Splitting. HortScience. 44(7):1-3 pgs 2035-2037.