This trial was set up to evaluate the efficacy of a test product on Bremia lactucae in lettuce indoor. Bremia lactucae is the agent of downy mildew in lettuce. In addition to the test product one chemical reference and the biological product LID1 based on Saccharomyces cerevisiae were integrated in the trial.
The trial was set up in a randomized block design, in 4 parallels and a plot area of 3.28 m² at a greenhouse in the research centre PCG in Kruishoutem (Belgium) on the variety Flandria (Rijk Zwaan, Bl: 1-17, 21, 23).
The plants were sown in 4 cm pots on 21/08/2013. The planting date was 6/09/2013. Harvest and destruction took place on 23/10/2013.
Preventive treatments were performed on 16/09/2013 (i.e. 8 days before artificial inoculation (DBI)), 20/09/2013 (4DBI) and 23/09/2013 (1DBI). The applications were performed by means of a backpack sprayer with a spray volume of 500 l/ha and an operating pressure of 3.8 bar. The test product was dissolved in 0.1% DMSO.
On 24/09/2013 an artificial inoculation with Bremia lactucae was performed following a protocol. Immediately after the inoculation the plants were covered with plastic during 1 day to create a high humidity.
On 8/10/2013 first symptoms occurred. Together with the artificial inoculation there was also a natural infection in the greenhouse: the untreated not inoculated object showed also symptoms on that date.
In this trial there was a severe infestation of Bremia lactucae. No visible symptoms are allowed for commercialization of the lettuce. Only the chemical reference product Fenomenal (66% fenamidone + fosethyl) kept the plants at first free from symptoms.
The test product (10mg/l or 100 mg/l) is not efficient against Bremia lactucae in lettuce indoor. The biological product LID1 (1 x 1010 cfu/g Saccharomyces cerevisiae) reduces the symptoms slightly, but this was not statistically proven.
Due to secondary infection none of the products could protect the plants at harvest. More than 2 treatments during the trial are necessary to be able to commercialize the lettuce.
Use of test product against Bremia lactucae in lettuce indoor 2013
|Teelt of thema|