INFLUENCE OF APHELENCHUS-AVENAE ON VESICULAR-ARBUSCULAR ENDOMYCORRHIZAL GROWTH-RESPONSE IN COTTON

  • 1 January 1981
    • journal article
    • research article
    • Vol. 13  (1) , 48-52
Abstract
The influence of A. avenae on the relationship between cotton (Gossypium hirsutum ''Stoneville 213'') and Gigaspora margarita or Glomus etunicatus was assessed by its effect on the mycorrhizal stimulation of plant growth and microorganism reproduction. The mycophagous nematode usually did not suppress stimulation of shoot growth resulting from mycorrhizae (G. margarita) at inoculum levels of 3000 or 6000 nematodes/pot, but retarded root growth at 6000/pot. When the nematode inoculum was increased to 10, 40 or 80 thousand, G. margarita stimulation of shoot or root growth was retarded at the 2 higher rates. Shoot growth enhancement by G. etunicatus was suppressed by 10,000 A. avenae but not by 40 or 80 thousand. A. avenae reproduced better when the nematode was added 3 wk after G. margarita than with simultaneous inoculations. Sporulation of both fungi was affected little by the mycophagous nematode. The high numbers of A. avenae required for an antagonistic effect probably precludes the occurrence of any significant interaction between these 2 organisms under field conditions.