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Nematodes and wireworms under control without granules
With the disappearance of chemical products, the challenge of controlling harmful nematodes in the soil increases. To prevent major losses in yield and quality of potatoes and onions, among other things, you must make the right choices in a construction plan. How do you handle that?
If you can no longer intervene chemically at the start of cultivation, it is important to look ahead. Sample the soil to gain insight into the populations of harmful nematodes. On plots where sensitive crops such as potatoes and onions grow, you want to start with the lowest possible populations. You can achieve this with a pre-cultivation that does not increase these nematodes or, preferably, greatly reduces them.
Combating nematodes with green manures
Without chemicals, a nematode-resistant green manure is the strongest weapon against harmful nematodes. The most effective green manures are:
- Multi-resistant fodder radish (Doublet): the only right choice for cyst nematodes and root knot nematodes (M. Chitwoodi, fallax, hapla, naasi).
- patula tagetes: with its roots that secrete toxic compounds, it actively kills root lesion nematodes (P. Penetrans) and thus depresses the population by 50% to 100% for several years.
- Japanese oats (Silke): has the same effect on P. Penetrans as black fallow, namely a reduction of 50% to 80%.
Be careful with mixtures of green manures. These usually contain host plants for harmful nematodes, allowing the population to multiply rapidly. Mobile nematodes actively search for their host plants in these mixtures.
Early sowing of green manures
For optimal effect, it is important to sow green manures as early as possible in the summer. For example, marigolds must grow for at least 8 to 10 weeks for the highest nematode kill and is very sensitive to frost. So you need a main crop that clears early, such as:
- winter barley: ready for harvest at the beginning of July, the latest varieties such as LG Zorica (fodder barley) and LG Zelda (malting barley) achieve high practical yields of over 11 tons with very low cultivation costs.
- Peas: you sow these leguminous plants until mid-April and harvest them from mid-July. Peas are a fairly easy crop that yield many points in the CAP and supply nitrogen to subsequent crops.
- Winter rapeseed: reliable dormant crop, harvest in July. Additional advantages: has a relatively high N usage standard and reduces problems caused by wireworms, because no eggs are deposited in it. The latest LG rapeseed varieties deliver high yields and are very hardy, meaning much less seed is left behind. View the varieties >
So take a good look at your construction plan and put the puzzle together for the coming years to keep your soil healthy and resilient. Knowing more? View our green manures of ask your LG cultivation specialist for advice.
