DATE OF PLANTING:

For each nematode species, there is a minimum temperature at which the nematodes are able to penetrate plant roots.

This table summarizes information available in the literature for important California nematodes.

If planting is to take place at a time of year when temperatures are below this infection minimum, or when soils are cooler, less damage can be expected than when soil temperatures are optimum.

Roberts and others have provided good demonstrations in the literature of how utilizing temperature at the time of planting can reduce nematode damage on carrots and wheat. This graph of soil temperatures over the period of a year relative to the minimum temperature at which M. incognita is able to penetrate plant roots demonstrates how altering the date of planting by only a few weeks can reduce nematode damage.

One main drawback to utilizing this technique can be in situations in which date of planting is driven by market values. It is generally more profitable to sell a particular crop when it is in short supply than when it is plentiful. Growers will try to time harvests to coincide with times they think it will be most profitable to market the crop. This timing may make it necessary to plant at times when nematodes are active.

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