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United States Department of Agriculture

Agricultural Research Service

Related Topics


Location: Crops Pathology and Genetics Research

2009 Annual Report

1a. Objectives (from AD-416)
Objectives are as follows: 1)Evaluate the impact of microbial inoculants on the incidence and severity of soilborne disease and on the overall health and vigor of bedding plants; 2)Evaluate the effect of adding pheromones to sticky traps on ability to monitor/detect thrips populations and for the potential to reduce thrips populations and the resultant damage on a variety of ornamental crops; 3)Evaluate the addition of silicon to ornamental crops to reduce damage by insects and mites and to produce healthier and more vigorous plants; and 4)Transfer effective new technologies to appropriate customer/stakeholder groups.

1b. Approach (from AD-416)
1) Through a series of research/demonstrations, will evaluate the relative performance of a variety of microbial inoculants compared to normal grower practices; 2)in cooperation with growers in California, will evaluate the use of pheromone/sticky traps on control of thrips in a commercial greenhouse; 3)in cooperation with growers, will run side by side comparisons of plants grown with and without the addition of silicon to determine if adding silicon to ornamental plants will increase their ability to resist attack insects and diseases and produce healthier and more vigorous plants; 4)will develop a Bedding Plant/Plant Propagators Alliance. Via meetings of this Alliance, will complete a Crop Profile for bedding plant producers and plant propagators. Documents SCA with UC Davis.

3. Progress Report
Silicon (Si) is second to oxygen as the most abundant element in the earth's crust. While its role in plant growth is not understood, its role in mitigating plants stress (abiotic and biotic) is beyond doubt. Despite this, little work has been done with ornamental plants, Si and arthropod pests. The addition of various forms of silicon to bedding plants and cut flowers was done in trials throughout California and on the Davis campus. Trials were conducted on chrysanthemums, roses, gerbera, zinnia, verbena and impatiens. We examined various forms of Si (potassium, calcium and magnesium) as an amendment to the fertilizer mix. Roots, leaves, stems and flowers were analyzed for the presence of Si. There was large variation between products and plants in terms of the Si found in various plant tissue. While data are in the final stages of analysis, we have determined that in roses grown for cut flowers, decreasing concentrations of silicon were found in the leaves, stems and flowers. This suggests that for insects attacking developing rose buds (i.e., western flower thrips), Si may not be effective in reducing damage caused by this pest. In general, no differences were observed in terms of insect or disease pressure on plants treated with Si vs. the untreated controls. Postharvest evaluations of gerbera under Si treatment are underway. In addition, a small trial was completed to evaluate whether Si would impact root knot nematodes attacking the roots of plants – a clear difference was found with the addition of potassium Si. Work with efficient microorganism (EM) is underway. We have learned how to formulate/ferment this product and will be using this is subsequent assays to improve overall plant health. A Bedding Plant Alliance has been formed in California and a number of presentations have been given to growers across the state to gauge their interest in participating. The goal is to reduce pesticide use in this industry by 30% over the next two years. This will be accomplished by implementing sound IPM strategies and by communicating these to alliance members through a newsletter and website. In addition, we will introduce the concept of adding Si and EM as soil amendments to improve plant health. Another phase of the BPA is to work with growers on new water sterilization technology that will allow them to reuse recirculated water without the fear or introducing plant pathogens into the crop. The ADODR monitors this SCA by maintaining a complete file of the agreement, reviewing the annual reports, and conducting meetings with the cooperator during the course of the agreement.

4. Accomplishments

Last Modified: 06/28/2017
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