Evaluation of some plant materials as organic mulch for the control of root-knot nematode (Meloidogyne spp.) and its impact on growth and yield of Celosia argentea L.

In an effort to explore a less toxic and a more environmentally compatible, cheaper and more easily available approach to the control of parasitic nematodes the leaves of three plants (Chromolaena odorata, Thevetia peruviana and Ocimum viride) were evaluated for their potential to protect Celosia argentea from damage by nematodes. A randomized complete block design experiment was established consisting of four treatments, replicated three times in an experimental area measuring 13m x 10m (130m 2 ). The results indicated that all the plant materials used had various degrees of negative impact on root – knot nematodes. The growth and yield components that were investigated were positively enhanced compared to the untreated controls. More root galls developed in the controls with very severe damage, followed by the plots treated with Thevetia peruviana and Ocimum viride with severe damage, while plots treated with Chromolaena odorata had only moderate damage. The study showed that C. odorata was more effective against root – knot nematodes.