by Sue Hinton, DSH PR
Leading the assault on garden pests is the humble nematode – a tiny creature that packs a huge punch. Nemaslug slug killer has been around for years, helping in the kitchen garden and the flower borders. Now there are nematodes to kill vine weevils, codling moth, cabbage white caterpillars, gooseberry sawfly, carrot root fly, cabbage root fly, onion fly, sciarid fly, cutworms, thrips, leatherjackets and chafer grubs.
Commercial growers use nematode products widely to control slugs and other pests in such crops as lettuces, potatoes, flowers and herbs and major retailers, including supermarkets, are recommending their use as they look to their own ‘green’ credentials and need effective controls without residues and the build up of resistance.
The good news too is that Britain is the world’s largest producer of nematodes, from Becker Underwood’s factory in Littlehampton, West Sussex.
Nematodes
So what are nematodes? Nematodes are roundworms, which means they have a digestive system like a tube. Believe it or not, there are more species of nematode than there are insects in the world. The ones used in pest controls are tiny microscopic worms, a quite basic life form but very effective. These nematodes naturally occur in our soil but their numbers are insufficient to deal with the target pest. So by adding a few million more (yes, you get millions per pack) you introduce enough of them to deal with the pest. Then, when the pest is eradicated, nematode numbers die back because their prey is gone.
A key benefit of using nematode pest controls is that they are safe for children, pets, wildlife and bees. No protective clothing is required nor is there any need to exclude children and pets from the area after treatment. Indeed you can eat vegetables that have recently been drenched with nematodes and when a packet of nematodes is received from your supplier it goes directly into the family’s fridge - to keep them cool until you use them.
How to use nematodes
Nematodes are applied to kill target pests in one of two ways. For pests in the soil, such as root fly maggots, you apply the nematodes as a drench to the soil where they will be, either with a watering can or a hose end feeder. For pests on the plant such as caterpillars, you spray the solution directly onto the pest. It’s best to start applying the nematodes when you plant out.
Ants are the exception. Ants are not killed, but they do not tolerate the nematodes near their nests and move them away from these areas, so you apply as a drench to the nest area.
Latest Developments
Last year Nemasys came up with an answer to many gardeners’ prayers – their new Nemasys Grow Your Own Fruit and Vegetable Pest Control. There is nothing more demoralising for home gardeners, and especially those new to gardening, than growing carrots, turnips, swedes or other root vegetables only to harvest them ready for the pot and find that they are full of root fly damage.
Nemasys Grow Your Own Pest Control is a unique and versatile mix of different nematode species to target a broader range of pests - some of the most common in fruit and vegetables. It has been specifically researched so home gardeners can control carrot root fly, cabbage root fly, leatherjackets, cutworms, onion fly, ants, sciarid fly, caterpillars, gooseberry sawfly, thrips, and codling moth. The application timing to control these tricky pests has been made easy too. By following the fortnightly programme approach gardeners do not have to worry about application times or thorough investigations as to what the pests actually are.
With the new Nemasys Grow Your Own mix whilst you are drenching the soil to target carrot root fly, you can also save some of the solution to spray the soil in your greenhouse for sciarid fly. Equally you can be spraying for caterpillars and if ants are also in the vicinity you can target them at the same time.
When killing above surface pests like cabbage white caterpillars and thrips make sure you spray the pests you want to kill directly with the nematode solution.
More Pests
Nemaslug has been at the forefront of nematode technology for years and every year demand increases. People who have used Nemaslug in contained situations, like a walled garden, a greenhouse or poly tunnel, report that slugs are almost non existent, whilst those that regularly use them on open areas, including allotments, see a dramatic reduction in numbers. When you remember that 95% of slugs live under the ground, it makes sense to target them there early in the planting season before they mature and can lay eggs. With successive six-weekly applications, the slug population takes a good knock.
Vine weevil is now endemic in the UK, but it’s the larvae in the soil that cause the most damage. They have a habit of eating the roots of many plants, including soft fruits. Using Nemasys Vine Weevil Killer in spring and autumn will sort out this problem.
Last year many gardeners were surprised by the late arrival of caterpillars and were taken unawares. They had protected their brassicas but unfortunately cabbage white butterflies can be very adept at getting beneath nets. The answer is Nemasys Caterpillar Killer. Spray the solution on to the caterpillars, doing so three times, each application a week apart to get the best coverage because the caterpillars hatch at different times.
Kathy Doyle, Deputy Head Gardener at Garden Organic, Ryton, has used Nemasys Caterpillar Killer to control Gooseberry Sawfly. Having spent ages squashing caterpillars, Kathy was keen to try an alternative approach. Says Kathy, “After the first application of Nemasys Caterpillar Killer I didn’t see any caterpillars but as the instructions told me to give it a further two drenches, I did so.”
All over the country and especially where there are sandy soils, chafer grubs and leatherjackets can play havoc with lawns. Yellow patches and birds and wildlife digging up the lawn are good signs of a possible infection. The birds and animals are looking for the tasty grubs. There’s a nematode solution for these pests too – Nemasys Chafer Grub Killer and Nemasys Leatherjacket Killer.
As we increasingly rely on nematodes as a safe and effective way of controlling pests in our gardens, the scientists at Becker Underwood continue their quest for different nematodes to kill more and more of our garden foes. If you consider how many millions of different species of nematodes there potentially are in the world it is no mean feat. Then once a nematode is discovered to combat a particular pest, it has to be rigorously researched and tested to make sure that it is indeed an effective nematode for the job in hand.
Source: DSH PR for Becker Underwood, the maker of Nemasys
