Role of Nematodes, Nematicides, and Crop Rotation on the Productivity and Quality of Potato, Sweet Potato, Peanut, and Grain Sorghum

Authors

  • A. W. Johnson
  • C. C. Dowler
  • N. C. Glaze
  • Z. A. Handoo

Abstract

The objective of this experiment was to determine the effects of fenamiphos 15G and short-cycle potato (PO)-sweet potato (SP) grown continuously and in rotation with peanut (PE)-grain sorghum (GS) on yield, crop quality, and mixed nematode population densities of Meloidogyne arenaria, M. hapla, M. incognita, and Mesocriconema ornatum. Greater root-gall indices and damage by M. hapla and M. incognita occurred on potato than other crops. Most crop yields were higher and root-gall indices lower from fenamiphos-treated plots than untreated plots. The total yield of potato in the PO-SP and PO-SP-PE-GS sequences increased from 1983 to 1985 in plots infested with M. hapla or M. arenaria and M. incognita in combination and decreased in 1986 to 1987 when root-knot nematode populations shifted to M. incognita. The total yields of sweet potato in the PO-SP-PE-GS sequence were similar in 1983 and 1985, and declined each year in the PO-SP sequence as a consequence of M. incognita population density increase in the soil. Yield of peanut from soil infested with M. hapla increased 82% in fenamiphos-treated plots compared to untreated plots. Fenamiphos treatment increased yield of grain sorghum from 5% to 45% over untreated controls. The declining yields of potato and sweet potato observed with both the PO-SP and PO-SP-PE-GS sequences indicate that these crop systems should not be used longer than 3 years in soil infested with M. incognita, M. arenaria, or M. hapla. Under these conditions, these two cropping systems promote a population shift in favor of M. incognita, which is more damaging to potato and sweet potato than M. arenaria and M. hapla. Key words: Arachis hypogaea, crop rotation, fenamiphos, grain sorghum, Ipomoea batatas, Meloidogyne arenaria, Meloidogyne hapla, Meloidogyne incognita, Mesocriconema ornatum, nematode, peanut, potato, root-knot, root-knot nematode, Solanum tuberosum, Sorghum vulgate, sweet potato.

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Published

1996-09-15

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Section

Articles