نسرين عيدروس علي ناصر

ملخص الدراسة

Summary

Pratylenchus spp. Is one of the most important agriculturally damaging nematode, it occurs in most locations in Yemen and affects many plant species. Chemical nematocides are usually persistent, expensive and carry the risk of ground water contamination.  Alternative method of nematodes control is highly needed. Available knowledge indicates that the use of other materials of biological origin (animal or plant) could be effective as an alternative nematode control method. The objectives of this project are to investigate the use of locally available materials of biological origin that could be used effectively as alternative nematode control materials in the Yemeni environment. With this objective in mind; Four materials of animal origin i.e. manures from Cattles, sheep, chicken and pigeons and four amendments of plant origin which were powdered leaves from the plant species of Nerium oleander (common oleander), Datura stramonium (Henbane), Pulicariia jauberti and Recinus communis  (Caster oil plant) were selected as the test materials.

 Methods and findings of the project:

  Preliminary survey was conducted in papaya fields to investigate the prevalence and extent of Pratylenchus spp. in the soil. During the month of August 2006, six fields were included in this study; four fields in Alhussaini, one in Nasser college of Agriculture and one in Gawaalah. The presence of Pratylenchus spp. was positive in all tested fields with variations in population density.

Water extracts from the plant leaves and the animal manures were tested in the laboratory to investigate their effects on the nematode Pratylenchus spp. The water extract of each type of the manure (faeces from Cattles, sheep, chicken and pigeons) and those from the plants leaves  (Nerium oleander (common oleander), Datura stramonium), Pulicariia jauberti and Recinus communis) were added to the nematode in 15cm. diameter Petri dishes.  All water extracts in the experiment showed 100% kill for the nematodes in 24 hours compared to the control.

The effects of the manures were also tested against the nematodes. An average of six plants were grown in a plant pot. With  Pratylenchus spp added to the soil in arrange of 000 to 2000 nematodes.. The manures and amendments were then added to the soil in a fermented form. The nematocidal effect the manures and the amendments were then compared with the chemical nematocide Mocab G10 and control. The results showed good response in the reduction of the nematodes population. Pigeon faeces gave best results followed by chicken faeces, but these two products did not improve plant growth. The manure from cattle and sheep gave less reduction in nematode population but produced obvious improvement in plant growth compared to the control.

The amendments of the plant origin that were used namely: Nerium oleander (common oleander), Datura stramonium), Pulicariia jauberti and Recinus communis) proved to be effective as nematode control in the soil as well as preventing its development in the plants roots .Datura leaves gave the best results followed by Pulicariia jauberti and Recinus communis  compared to the control

The residual effects of the manures and that of amendments were also investigated. The cattle’s manure was shown to be effective in reducing nematodes population in the plant routes as well as in the surrounding soil, while that from sheep lost it its residual effect. The chicken and pigeons manures shown residual effect only in the plant routes as demonstrated by reduction of nematodes in the plant route and an in crease in the soil. In the case of the materials of plants origin, only the leaves from Pulicariia jauberti and Recinus communis demonstrated residual effect by continued reduction of the nematodes population, both in the plant routes and the surrounding soil.