ROOT LESION AND ROOT-KNOT NEMATODES ASSOCIATED WITH CROPS GROWN IN ROTATION WITH CARROTS ON PRINCE-EDWARD-ISLAND

Population levels of root lesion nematodes (primarily Pratylenchus penetrans) and northern root-knot nematodes (Meloidogyne hapla) were examined in crops that precede or are grown in rotation with carrots on Prince Edward Island. Root lesion nematodes were most prevalent in red clover, hay (red clover-timothy mixture) and potato fields. The largest populations of northern root-knot nematodes were found in carrot fields. The effect of P. penetrans on carrots grown on Prince Edward Island has not been investigated, but M. hapla can be a serious problem and continuous cultivation of carrots should be avoided. In addition, crops such as barley, wheat, or annual ryegrass, that are not hosts for M. hapla, should be included in the rotation.