Greenhouse testing of oil products against carrot psyllid (Trioza apicalis)
Abstract: Oil products, Sun 7E or Carbon Kick® Booster, were sprayed on carrot seedlings at the one-leaf stage in concentration of 1.5% to test their efficacy against carrot psyllid adult and nymphal feeding. The first spray was done before releasing one female psyllid per each seedling. Adult psyllids were removed manually after a three-day exposure period. Plants were sprayed a second time when the nymphs were hatched. The spray with oil products did not increase adult mortality. Booster, however, significantly reduced the number of eggs laid per seedling and the number of nymphs per leaf compared to water treatment. Oil treatments, however, did not have significant effect on carrot yield. Booster treatment slightly increased the root weight in control plants, but reduced the root weight in psyllid-exposed plants more than in the other treatments. Triacontanol, added to rapeseed oil in Booster, together with carrot psyllid damage may change photosynthate allocation between the plant organs. Therefore, rapeseed oil products should be tested against carrot psyllid without additional triacontanol.