This trial was set up to evaluate the efficacy of a mixture of lipopeptides mycosubtilin and fengicin on Bremia lactucae in lettuce indoor. Bremia lactucae is the agent of downy mildew in lettuce. Is there an effect on Bremia in lettuce?
In addition to the lipopetides one chemical references 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 in Kruishoutem (Belgium) on the variety Flandria (Rijk Zwaan, Bl: 1-17, 21, 23).
The planting date was 17/04/2013. Harvest took place on 24/05/2013.
Preventive treatments were performed on 22/04/2013 (i.e. 8 days before artificial inoculation (DBI)), 26/04/2013 (4DBI) and 29/04/2013 (1DBI).
The applications were performed by means of a backpack sprayer with a spray volume of 500 l/ha and an operating pressure of 2.0 – 3.8 bar. The lipopeptides were dissolved in a 0.1% DMSO solution.
On 30/04/2013 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 17/05/2013 first symptoms occurred, the number of infested plants were counted. 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. One week later, on May 24th, the percentage diseased leaf surface per plot was estimated.
In this trial there was a severe infestation of Bremia lactucae. To be able to sell the lettuce no visible symptoms are allowed. In this trial only the chemical reference Fenomenal (fenamidone + fosethyl) kept the plants at the first assessment free of symptoms. The symptoms on May 24th were due to a secondary infection, on that moment the chemical product also could not protect the plants anymore. The biological product LID1 and the lipopeptides were not efficient to control the Bremia lactucae infection in this trial.
Use of Bacillus subtilis lipopeptides against Bremia lactucae in lettuce indoor 2012
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