ROOTS, RHIZOMES AND RHIZOPHAGA

A commentary on the growth and development of roots and rhizomes and on how they may affect or respond to certain abiotic and biotic components of the soil, especially nematodes and fungi. Several complex inter relationships are mentioned including one in which the ageing process of the whole plant is hastened; one in which the roots are made unsuitable for succeeding parasites; and one in which a fungus appears to be a common but symptomless parasite. A report of trials involving mycorrhizal fungi shows that they may provide some protection for carrots against the root-knot nematode Meloidogyne hapla, but no protection for tomato roots against these nematodes, or to the fungus that induces Fusarium wilt.