Wednesday, January 9, 2013

Gardening Article: Increase Your Crop Yield by Using Marigold in Permaculture

Permaculture is basically about how plants and animals are dependent on each other in their respective functions in nature. There is a general belief among gardeners that planting a combination of plants in a garden can prevent insect infestation.

Marigold is often recommended as a plant which can be used in gardens to prevent nematode and insect damage. However, there are doubts about marigold ability to repel insects. One particular pest that favors marigold is Spider mites, and since these pests are also attracted to other vegetables such as tomatoes it wouldn’t be beneficial to plant marigold with these crops. Spider mites can accumulate on marigold and then spread out to your vegetable plants.

Marigold Control Nematodes

Marigold can help to keep those dangerous nematodes under control. Nematodes are tiny microscopic worms that invade the roots of several vegetables and cause a decline in both the quality and yield. Nematodes favorite plants are tomatoes, but now-a-days the majority of tomato cultivars are bred to be nematode resistant. If your garden is under nematode attack, the adverse effect will be visible by the middle of summer.

Marigold produces a substance that deters nematodes. Research indicates that asparagus, castor beans, pangola grass and neem all produce substances which can kill one or more types of nematodes. Marigold is unlike these plants in that it acts like a trap crop. As the nematodes move onto the plants, they die because they are unable to generate any effective breeding site. Marigolds can control many kinds of nematodes but they are most effective on the root-knot and legions types.

When and How to Plant Marigold

Nematode control is dependent on how marigold is planted and the time it is planted. It doesn’t make sense to plant them beside crops that are prone to root-knot nematodes because this will not be effective, since the root-knot nematodes will amass on predisposed plants. The best thing to do is to plant marigold as cover crops. You should plant marigolds in the rows or the areas where you intend to lessen the problem of nematode build-up. The early crops for summer such as cucumbers, garlic, squash, snap beans, tomatoes, onions and strawberries are usually removed after they have completed their production. You can plant marigold in the same place where these uprooted plants were planted.

Since marigold will only be effective in controlling nematodes for just one crop, you should ensure that the necessary precautions are to be taken to prevent an increase in the nematode population.

Identifying Nematodes

Nematodes are present in all soil types. While these parasitic nematodes are there, they do not have to be present in such great numbers so as to create a problem in your plants. They only pose a problem when the population is large. Nematodes are microscopic in size; therefore if you suspect that they are present in your garden, it’s impossible to see them with your naked eye.

When you become suspicious of their presence call on your Agricultural Extension Office and ask for nematode assay kit. Soil samples that you collect and submit will be tested in the lab for evaluation. If the sample shows high levels of nematode, and is cause for concern, then marigold can be used as a cover crop for control.

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About the author: Lucas Barnes writes about gardening on his site Plantdex.

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