Tomato (Lycopersicum esculentum Mill) is one of the most important vegetable crops cultivated in Egypt, where about 395,112 feddans of tomato are grown to produce 6,042,130 tons, and approximately 9599 feddans only grown in Dakahlia Governorate to produce 88,463 tons during the growing season of 1995. The reniform nematode, Rotylenchulus reniformis Linford and Oliveira is a major soil nematode pest that causing serious injury to tomato in temperate and tropical regions. Infestations of this nematode to such plant result in yellowish leaves, stunting, poor plant growth and yield losses.
Chemical control of R. reniformis has successfully limited the effect of this nematode below damaging levels. However, environmental, health problems and disturbance in the biological balance of nature that caused as a result of extensive use of nematicides have enhanced scientists to search for another alternative nematode management. Biological control of plant parasitic nematodes with microbial agents or natural plant extracts is an alternative method. This trend is receiving greater interest among nematologists in recent years, providing effective control against the target nematode and avoiding environmental pollution.
Therefore, the objectives of the present investigation were:
1. to evaluate the nematicidal properties of certain aqueous leaf extracts or plant products against R. reniformis under laboratory conditions,
2. to assess and compare the effectiveness of three different application methods of aqueous leaf extracts or plant products on susceptible tomato cultivars infecting with R. reniformis, and its rate of reproduction under greenhouse conditions; and
3. to evaluate the effect of the tested leaf extracts or products on N, P and K status of tomato plants infected with R. reniformis.