FE ATURE ◗ B. PRITHIVIRAJ
Compost Tea For the management of dollar spot and snow mold ◗ The first field season has now been completed and a series of data representing the performance of compost tea under field conditions is currently being analysed. New composts have been produced and are being screened for their use in the up-and-coming field season where their efficacy will be tested in the field conditions. The effect of compost tea on overcoming the toxin produced by the pathogen has been tested and is nearing completion. A series of induced resistance tests are underway as well. A new inoculum has also been produced and is working quite well to represent field conditions in the greenhouse.
Field Experiment
A field experiment was conducted this past spring, summer and fall. Two sampling sites were selected on a local golf course, (Mountain Golf and Country Club, Valley, NS) as well, a double set of plots were selected on our experimental green located at the ATRC (Bible Hill, NS). The design consisted of a 3x4 randomized design and individual plots were one meter by two meters in size (Figure 1). This design was duplicated at all sampling sites. The plots were treated once a week with either 50% compost tea, 100% compost tea or distilled water as a control. Data was collected on the diameter of visible dollar spots as well as number and location within the plots. A grid was used to track location and number. This data is currently being analysed in order to determine trends and patterns across the three treatments at the various locations.
Toxin Experiment
The toxin work is also moving along quite well. An in-vitro micro climate has been designed in which the grass can be exposed to compost tea treatments, as well as toxin, and perform in a fully measurable manner. In this setup, we can collect root data and measure the amount of disease damage the toxin inflicts on the growing tissue of the plants. One trial has been completed, trials 2 and 3 are currently underway, and data will be collected very soon.
tea exhibited resistance to the dollar spot pathogen. Blades from the treated plants where green while the water treated blades turned chlorotic (Figure 2). The result suggests that compost treatment induced systemic resistance in the grass against dollar spot disease.
New Inoculation Method FIGURE 1: A ONE METER BY TWO METER EXPERIMENTAL PLOT LOCATED AT THE ATRC (BIBLE HILL, NS)
Compost Completion
The mature composts are now ready and preliminary tests are underway to test which compost show the most promise for use in the up-and-coming field experiment. These composts are of known sources and contain only specific feedstocks. We hope that by controlling the feedstock in the compost we can control for any compounds we might find in the completed tea.
Induced Resistance Study
A series of greenhouse experiments were conducted to test the effect of compost tea treatment on the resistance of creeping bentgrass. The plants were treated with 50% compost tea, 100% compost tea and distilled water. Forty-eight hours after the last treatment, blades were harvested and placed on a clean glass slide and inoculated with mycelial plug. The slide was then placed in a moist chamber and incubated at 22-25°C and observed at day three and day five after inoculation. At both observation times, the plant treated with compost
A new inoculum procedure has been tested and is currently what we are using for all experiments. This new method better represents what is the proposed method of natural infection that the fungus surviving unfavourable periods in the plant debris at the soil level. This new method of using millet seed as the medium for growth and then inoculating with that seed represents a more naturalistic type infection compared to that of the direct placement of the mycelium-covered, PDA plugs.
Isolation of Snow Mold
New samples have been collected from the ATRC and isolation of a pure culture of gray snow mold is currently underway.
Plan for spring and summer
1. Field trial with the compost tea (cow, mink or chicken) that performs best in the current greenhouse trial to against dollar spot. These trials will be conducted at Mountain golf course and ATRF. 2. Observe the snow mold incidence in plots that were treated with compost tea during the spring and summer of 2010. GM B. Prithiviraj, Department of Environmental Sciences, Nova Scotia Agricultural College
FIGURE 2: A FLASK OF MILLET SEEDS ON THE RIGHT NOTICE THE YELLOW COLOUR. THE PICTURE ON THE LEFT REPRESENTS A FINISHED INOCULUM READY FOR USE THE SEEDS ARE NOW WHITE FULLY COVERED WITH FUNGAL MYCLIA. MAY/JUNE 2014 | GreenMaster 27