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JAAST Table of Content: February - 2015, 3(2)

Short Communication

Okorocha E.O.A1, Olojede O.A1. Ogbuji R.O2., Onyeka, T. J1. and Ano, A.O1   pp. 19 - 20

STUDIES ON EFFECTS OF DIFFERENT INOCULUM DENSITIES OF ROOT –KNOT NEMATODE MELOIDOGYNE INCOGNITA ON GROWTH OF HAUSA POTATO SOLENOSTEMON ROFUNDIFOLIUS POIR

 

           

A greenhouse experiment was carried out in National Root Crops Research Institute (NRCRI), Umudike, Nigeria to evaluate the effects of different inoculum densities of root-knot nematode, Meloidogyne incognita on growth of Hausa potato. The experiment consisted of six M. incognita inoculum levels in five replications set up in complete randomized design. The results revealed that there was significant density effect on stem weight. The economic threshold level of the nematode inoculum at which significant damage was obtained was 500 eggs/plant. However there was generally no significant effects of the root-knot nematode on some growth parameters as well as on the pest incidence in the soil and roots of the crop.

Keywords:  Root-knot nematode Meloidogyne incognita, inoculum densities, Hausa potato Solenostemon rotundifolius.

Research Articles

Okorocha E.O.A1., Olojede O.A1. and Onyenobi F. Ijeoma2   pp. 21 - 24

THE EFFECTS OF PRE-PLANT TREATMENT WITH NEMATICIDAL PLANT EXTRACTS ON INFECTIVITY OF ROOT-KNOT NEMATODES MELOIDOGYNE SPP ON LIVINGSTONE POTATO PLECTRANTHUS ESCULENTUS (RIZGA)

 

           

Field experiments were conducted in 2008 and 2009 growing seasons at National Root Crops Research Institute (N.R.C.R.I.), Umudike, Abia State Nigeria to evaluate the effects of pre-plant treatments with nematicidal plant extracts on the productivity of Livingstone potato (Rizga) and to determine the level of control contributed by them in reducing the infectivity of root-knot nematodes Meloidogyne spp. on the crop. The experiments consisted of two ‘Rizga’ varieties, five treatments and three replications laid out in randomized complete block design. The results showed that there were no significant effects of the nematicidal plant treatment on growth though control plants had higher growth and yield values than treated plants. Riyom variety had significantly higher values than Loangat variety for all the growth parameters measured in 2008 (Table1). No significant interaction was obtained between variety and treatment for both years for all the parameters measured and for the Meloidogyne spp. damage symptoms, Riyom variety had higher severity index in both 2008 and 2009 growing seasons. In addition though treatments were not significant for both years, pre-plant treatments with ginger, golden seal and alligator pepper extracts had remarkably lower values when destructively sampled for eggs. These plant extracts therefore offer promising alternatives to root-knot nematode control.

Keywords:  Meloidogyne spp., pre-plant treatment, nematicidal plant extract, Livingstone potato (Rizga).