root knot nematodes in potatoes
Your description sounds like the traditional explanation of nematode damage on potatoes. A positive identification of the problem can be determined by the Texas Plant Disease Diagnostic Lab. http://plantclinic.tamu.edu/forms/d827/ If it is nematodes, the potatoes are edible if peeled. “Above ground symptoms are similar to many other root diseases or environmental factors limiting water and nutrient uptake. These symptoms consist of wilting during periods of moisture stress, stunted plants, chlorotic or pale green leaves, and reduced yields. Most characteristic symptoms; however, are those occurring on underground plant parts. Infected roots swell at the point of infection and form knots or galls.” Control
- Crop Rotation – a three or four year rotation program with resistant crops is an effective program. Most of the cereal crops are fairly resistant. A little more detail on crop rotation for vegetable gardens can be found at: http://lubbocktx.tamu.edu/horticulture/docs/vegrote.html
- Clean Summer Fallow – dry summer fallow with cultivations every 3 to 4 weeks is an effective method of reducing nematode populations. This method may be impractical in some instances.
- Selection of Planting Stock and Planting Sites – Select transplants free of root knots. Plant roots should be washed and carefully inspected for signs of nematode injury. Select planting sites free of nematode infestations. An indicator crop of tomatoes, okra or other susceptible plants could be grown in the area if you do not know rotation histories. Submit soil samples to the Plant Nematode Detection Laboratory for analysis.