'NEMguard good alternative in the fight against nematodes'

Arable farmer Berend Jansema works on healthy soil life and a resilient crop. This includes the use of green resources, he says. The Groninger tried the drug last season as a test NEMguard in onions, as a natural alternative to Vydate. The results are good, he says. "Both products are comparable in yield and quality."

It is busy on Jansema's yard in Sellingen, Groningen. Trucks drive back and forth to load onions. The arable farmer grew 2023 hectares of onions in 20, of which 1,5 hectares on a test plot with the green product NEMguard from Certis Belchim. Jansema had actually wanted to start working with the drug a year earlier, to gain more experience with it, now that Vydate will no longer be allowed from 2024. "After one year you cannot say whether a product works or not. Every season is different, with different challenges."

Steer for saprophagous eels
Jansema has been using green products in starch potatoes for four years. That's going well, he says. "If you want to get started with soil life, you have to look for green alternatives; apart from the fact that fewer and fewer chemical products are being approved. We are on sandy soil, onion cultivation is a growing crop here, but at the same time the nematode problem is a challenge. However, I prefer to focus on good saprophagous eels for soil improvement rather than on combating harmful eels. With Vydate you are combating the symptoms. We need to move towards healthy soil and a strong crop."

The arable farmer obtains his products from agricultural wholesaler Johan Schuitema in Mussel. "In the steps we take to become more sustainable, we consult with Schuitema what options and resources are available on the market," says Jansema. Johan Schuitema continues: "As a company, we try to be at the forefront of developments towards sustainable arable farming. We are therefore very happy with an entrepreneur like Jansema, who dares to implement sustainable methods on his farm on a large scale. That is great for us. company, but that also raises expectations."

This means that regular consultation about the purpose of the greening trials is essential and that risks must be covered, according to Schuitema. "Jansema does not have a test company. That is why it was decided not to create an untreated bed in this test. We did investigate in which system NEMguard fits best. This system approach also takes place in green products in starch potatoes. We also try to relieve the arable farmer as much as possible during the trial. We have to be careful with these types of addresses."

Four systems in the test
The test with NEMguard has been installed on onion beds of 250 to 280 meters, in a system with a Vydate track with starter fertilizer, a NEMguard solo track, a NEMguard track with starter fertilizer and a NEMguard track with starter fertilizer and biostimulants. This is a double repetition. The onions of the Fasto variety were sown on April 6 and the product was applied in the form of granules directly during sowing. Soil samples were taken before sowing to determine the nematode pressure on the plot. Tagetes was sown as a preliminary crop to clear up the root lesion nematode (Pratylenchus penetrans).

The first condition for a good onion yield is that you know the starting position of your soil, says Schuitema, nematodes are never in one place in a plot. Soil samples showed that in addition to root lesion nematodes, there are also free-living nematodes (Trichorids) in the soil. "With marigolds as a pre-crop you control the root lesion nematode, but the plant multiplies the free-living nematode. That is why it is important that you have a good idea of ​​the size of the nematode population on a plot. NEMguard works on almost all types of harmful eels, but has no effect on saprophagous eels. You can use the product safely without harming soil life."

Garlic as active substance
NEMguard is a green product based on garlic extract, says Fokke Smit, senior technical account manager at Certis Belchim. The product provides protection against harmful nematodes and also has a side effect on the onion fly. By processing garlic according to a patented process, a sophisticated mixture of high-quality polysulfides is created. When these multiple sulfur compounds come into contact with nematodes, they penetrate through the skin. Various reactions then take place in the interior of the nematodes, to which the nematodes succumb, he explains.

The product can be applied with a granule spreader while sowing onions, so that the granules are placed close to the seed. NEMguard is formulated as a kind of slow release granule, according to Smit. "The moment a nematode comes into contact with NEMguard, it dies. The product works for six to eight weeks, after which the onion plants must be developed in such a way that they can control the nematodes. That is why it is important that the plant after sowing can grow well, by using, among other things, primed seed and a starter fertilizer." The drug also has a side effect against the first flight of the onion fly.

More plants on test plot
During the trial, crop development was monitored weekly. During the first plant counts, the plot contained: NEMguard more plants were treated than on the regular onion plots to which Vydate had been applied. At the beginning of the season, the color on the regular plots was nicer than on the test plot, but that improved later and you no longer saw a color difference, says Smit. The yield from both the regular plots and the test plot was around 75 tons/ha, he says.

The onion beds have been completely harvested and passed over the weighbridge to get the best possible picture, Schuitema adds. "We can say that this trial this season has shown that you can grow onions by replacing Vydate with NEMguard. That is a positive fact, although we can never guarantee that it will work every year. We now had a late onion year, then the plant can develop well. If you sow early in March and it then becomes cold and wet, the crop will grow more slowly, which means it may suffer more from the nematodes present. We always say: don't sow too early. But if the soil is suitable, farmers often go onto the land anyway," he knows from experience.

Full-fledged alternative
Schuitema and Smit think that NEMguard can be a full-fledged alternative to Vydate to continue growing onions on the sandy soils of Northeast Groningen. Arable farmer Jansema says he certainly wants to continue with the drug. “We grow 20 hectares of onions, we have to look for other solutions. There is a chance that we NEMguard will be used as a specific insurance policy in 2024. The product is an opportunity to continue onion cultivation here. We still have to find out whether we use it solo or in combination with other products. With Vydate we combated symptoms; Now we must ensure that the crop becomes more resilient so that it does not sustain damage. That is a challenge, but we have seen in potatoes that it is possible."