Efficacy of compost tea on Septoria leaf spot in field and greenhouse studies
The calendar year of 2007 saw activities from laboratory processes being finalized to the completion of the field-based research. Also, the manuscript was produced after the growing season in the fall.
In the laboratory, final protocol for production of Septoria lycopersici was developed. Through various trials on plate contents, concentration of inoculum, and incubation conditions, optimal procedures were identified. In the greenhouse, final protocol for infection of tomato plants with Septoria lycopersici was developed. Several variables, such as inoculum concentration, length of time in the mist chamber, and leaf wetness were investigated to provide optimal infection rates.
Using the basic principles of compost tea production used in the field in 2006, an apparatus was designed to produce six small compost tea batches in the laboratory. The quantities of ingredients were directly proportionate to the recipe used in the field. Dissolved oxygen levels were measured to ensure that comparable conditions were being provided to each individual compost tea batch.
With the development of these very important procedures, research on the compost tea bioassay progressed.
The objectives of this portion of the project were to develop these procedures and facilitate their utilization through the testing of young tomato plants. Plants were treated with compost teas produced in the developed apparatus, then subjected to inoculum applied at the optimal concentration. Plants were then placed in the growth chamber for an optimal period of time, under optimal conditions. When plants were removed from the mist chamber, normal maintenance was performed until disease analysis was completed.
In 2007, the second and final season of trials were initiated and completed. During this season, farmer involvement was initiated at the private farm level. Two trials were conducted, one on the research plots utilized in the 2006 season, and one on the private market farm identified in the final report.
Weekly applications of compost tea were made to the respective plots for analysis and comparison to fungicide treated plots (research farm only) and untreated control plots. The research farm and market farm trials were conducted for 13 and 11 weeks, respectively. Disease ratings were taken starting on the 9th week after transplant.
Through the completion of the laboratory/greenhouse and field-based research, a manuscript in the form of a Master of Science thesis was produced. A draft of that manuscript can will be submitted for the final report for this project.