NEMguard against nematodes and carrot fly

Now that Vydate is no longer permitted for the control of nematodes, growers have to rely on alternatives. For the cultivation of carrots NEMguard with dot at the top. Not only because of its good effect on various nematodes and its suitability for IPM and organic cultivation. This natural remedy based on garlic extract also works against carrot fly larvae. So double protection against both nematodes and carrot fly. "In terms of yield, NEMguard is not inferior to Vydate and the root quality is even better," says technical account manager Harry Hansma of Certis Belchim.

NEMguard is a unique granular formulation of garlic extract with diatomaceous earth as a carrier. It has been approved since 2016 to combat and prevent damage caused by various nematodes, carrot and onion flies in a wide range of crops in arable and horticulture.

"Until last year there was a modest but loyal group of users, especially in onion and carrot cultivation," says Hansma. "This is partly due to its good effect against carrot and onion flies and its suitability for IPM and organic cultivation methods. Now that Vydate is no longer permitted, more growers will become aware of the potential of NEMguard. We already saw an increase in its use last year. Practical tests were also carried out again, in both carrots and onions. These confirmed that NEMguard shows very good results on plots with a light to medium nematode presence. After an application in the spring during sowing, the garlic extract remains for six to eight weeks. active."

Effect of garlic extract
Garlic extract is the active ingredient NEMguard. By processing the garlic according to a patented process, a mixture of high-quality polysulfides is created. When these multiple sulfur compounds come into contact with nematodes or fly larvae, they penetrate through the skin. Various reactions then take place in the interior of the nematodes, to which the nematodes soon succumb.

NEMguard is effective against all harmful nematodes. The product also works in the same way against carrot fly larvae. An early spring application during sowing effectively protects the carrot crop against the first flight of the carrot fly.

Trial results 2023
Over the years, NEMguard has been used in dozens of field trials in several crops. One of the most recent involved a test in wax carrots on a plot in Hooge Mierde. In this trial, strips were compared that had been treated with Vydate or in accordance with the usage recommendations NEMguard. The trial was supervised by the independent research institute HLB, which sampled six times during cultivation.

Crop manager open field horticulture Edwin Hendriks from Certis Belchim talks about the results: "The seedbeds that were treated with NEMguard showed better emergence, but there were no significant differences in yield and size grading. It was striking that the quality of the harvested carrots was better. in the NEMguard strips. The number of carrots with branches due to the attack of nematodes - especially Pratylenchus penetrans - was clearly lower (3% compared to 11%). The proportion of good quality carrots with the NEMguard treatment was 89%, while with The Vydate treated portion turned out to be only 78%. As a result, this product came out on balance as the best." Hendriks adds that NEMguard has been successfully tested and applied in recent years in carrot crops throughout the Netherlands, ranging from bunch carrots on light soil to wax carrots and winter carrots on heavier soils.

Apply during sowing
NEMguard Apply during sowing using a granulate spreader. The dosage is 20 kilos per hectare. Application is possible with many types of granulate spreaders with the exception of Gandy spreaders. To protect the root against nematodes, sufficient moisture is important for six weeks after sowing. The advice is approximately 10 millimeters of water per week. A moist soil is sufficient for a good effect against carrot fly.