Effect of Temperature on Suppression of Meloidogyne incognita by Tagetes Cultivars

  • Antoon T. Ploeg
Keywords: marigold, meloidogyne incognita, nematode, root-knot nematodes, suppression, tagetes, temperature


The suppression of Meloidogyne incognita by marigolds differed among six marigold cultivars and five soil temperatures. Tagetes signata (syn. T. tenuifolia) cv. Tangerine Gem and the Tagetes hybrid Polynema allowed reproduction and root galling when grown at 30 ºC, and should not be used for control of M. incognita at temperatures close to 30 ºC. Tagetes patula cultivars Single Gold and Tangerine and T. erecta Flor de Muerto, when grown within a 20-30 ºC soil temperature range, significantly reduced root galling and nematode infestation of subsequent tomato compared to tomato following fallow. When grown at 10 ºC or 15 ºC, only one of the tested marigold cultivars (T. erecta CrackerJack at 15 ºC) reduced M. incognita infection of subsequent tomato compared to tomato after fallow. Marigolds should be grown at soil temperatures above 15 ºC to suppress M. incognita infection of a subsequent crop.