Integrated control of the root-knot nematode, Meloidogyne incognita, on black-pepper plantations in the amazonian region

In the Amazonian region, so-called foot-rot disease, caused by a fungus Nectria, occurs widely on black-peppers, Piper nigrum L., the roots of which are also heavily infested by the root-knot nematode, Meloidogyne incognita. Factorial experiments were conducted in this region during 1976–1978 to attempt to find out the effect of nematicide treatment, mulching with Imperata cylindrica, and non-host cover plantings, on the growth of black-peppers as well as on nematode population levels. Temic or Furadan treatment resulted in better plant growth and a reduced nematode population in the first year. Mulching resulted in exceedingly high plant growth, even though higher nematode populations were also observed. Under mulching conditions, soil temperatures at 5-cm depth seldom rose beyond 30°C throughout the year. Cover plantings of non-hosts, which had been selected by earlier inoculation tests, indicated remarkable retardation of plant growth of black-peppers, evidently due to the competition, and this also reduced the nematode population. Macroptilium atropurpureum (siratro) gave the smallest growth retardation of black-peppers. From these results, a combination of three procedures, i.e. Temic or Furadan treatment, mulching with grass straw, and cover-planting of non-hosts such as siratro, is recommended on black-pepper plantations for better plant growth and eventually better yield of black-peppers in the fields infested by root-knot nematodes.