Nematodes

Nematodes can substantially reduce yield of watermelon.  The affected plants are stunted and chlorotic.  Root-knot nematodes can cause galling on roots [WMD47.JPG], but there are no visible root symptoms with the reniform nematode.  The root-knot nematode occurs primarily in sandy soils.   Although nematicides can provide an economical control, a crop rotation with corn or sorghum and a weed-free fallow can reduce numbers of nematodes below damaging thresholds.