Non Food Horticultural Crops

Current Research        

The ornamental industry identified scale as one of the highest research priorities for nursery crops. Research has begun to discover an effective and environmentally sensitive control for scale insects in ornamentals and to develop an integrated pest management strategy based on the life history of soft scales (Coccidae family, characterized by a waxy covering on the insect's body). The research will examine the effectiveness of combining degree-day information with reduced-risk insecticides. While ill-timed insecticides are often ineffective, scale insects are prone to a variety of natural enemies, most of which are harmed by more toxic insecticide sprays. It is anticipated that less toxic, more targeted insecticides – when used at the proper time in the insect’s development – will conserve natural enemies.
Species of Phytophthora cause some of the most serious damage and subsequent economic losses to ornamental crops in nurseries, as well as to trees in natural ecosystems, particularly in the southeastern U.S. Research is underway to develop better methods of detecting this species in nurseries and natural ecosystems, and to monitor the occurrence and distribution of the pathogens so improved disease management practices can be developed and implemented. Ultimately, this will result in improved plant health, increased profitability for ornamental crop producers and retailers, and more sustainable landscapes and forests. Methods for detecting Phytophthora species in plants, soil and water have been developed that appear to be highly effective, with additional testing and evaluation underway.

Outputs/Outcomes       

Experiments were conducted to determine the effect of fertilizer concentration applied to stock plants on cutting production, cutting quality, postharvest performance and rooting in propagation. This research provided new guidelines for the improved production, transport and propagation of un-rooted cuttings that have been implemented by South Carolina growers.
An environmentally sustainable water treatment system, called a constructed wetland system, developed by Clemson research is serving the nursery and greenhouse industries. Tailored to manage nutrient, pesticide and pathogen contaminants, it can provide an environmentally sound and economically feasible alternative to traditional systems. Results from this research showed measurably cleaner water using the new system. Nitrogen, phosphorus, temperature and Phytophthora spp colony-forming units were consistently lower after water was treated in the constructed wetland.
Fine root activity is a crucial determinant of plant productivity, ecosystem nutrient cycling and global carbon sequestration. A multi-year study was completed on soil compaction and amendment treatments for urban trees, using the latest miniature camera equipment and RootFly minirhizotron image analysis software. Statistical models were developed that relate urban tree root growth to soil water content and temperature.  Mulch was found to be the most effective of the individual treatments, increasing both organic matter and water content of the soil.
The U.S. micro-propagation industry, with more than 150 laboratories nationwide, is under pressure from low-cost imports. Research to lower the cost for U.S. laboratory production of plant material yielded progress in developing a liquid-matrix system that prevents hyperhydricity in sensitive plants, both herbaceous and woody. Specific nutrients also were identified that are critical to the subsequent growth of laboratory plants in greenhouse nurseries. Response surface methods and experimental platforms have been developed to allow in vitro biologists to refine media formulations for critical applications.