A survey was conducted to different vegetables growing areas of Punjab [Faisalabad, Jhang, Khanewal, Multan, Rawalpindi, Lahore and Toba Tek Singh] for reliable estimate of root knot nematodes infestations and occurrence of Pasteuria penetrans. A total of 270 samples of cucumber and tomato were collected. Out of 141 samples of cucumber 63 (44.68%) were infected with root knot nematodes and 51(39.53%) samples were found to be infected with RKN in case of tomato out of 129 samples. At now 85% of these samples are processed, analyzed and their populations are maintained in the pots.
Root knot nematodes are one of the most destructive nematodes as due to gall formation on root of plants their function is disturbed and there is obstruction in water and nutrient supply due to which plant become weak and ultimately death of the plants may occur. Phytoparasitic nematodes are among the most difficult crop pests to control (Chitwood, 2002). They are severely damaging a wide range of agricultural crops, causing serious yield losses worldwide, especially in the tropical and subtropical agriculture, where environmental factors favour survival and dispersal of nematodes. Among the root–knot nematodes, Meloidogyne spp., M. javanica, M. incognita, M. arenaria, and M. hapla,are of agronomic importance, being responsible for at least 90% of all damage caused by the nematodes (Castagnone-Sereno, 2002). Meloidogyne species are a tremendous threat to crop production (Sasser and Freckman, 1986). This menace could be more devastating in third world countries, where most peasant farmers are unaware of the ravages of these “hidden enemies” and would not accordingly take remedial steps to manage these pests.
In Pakistan the root-knot nematodes problem is more damaging than in developed countries because the country has tropical and subtropical regions where the climate is suitable for nematode activity throughout the year in one or other part of the country. Sandy and warm soil is favourable for nematode infestation, especially in irrigated areas where crops are grown continuously. In Pakistan major nematode problems that cause great damage to agricultural production are due to Meloidogyne incognita and M. javanica. They attack many vegetable crops, fruits and ornamental plants throughout the country. Nematode control is far more complex than other kinds of pathogens because nematodes mainly attack underground parts of plants. In Pakistan chemicals nematicides like, Furadon 3G (carbofuran), Temik, 10G (aldicarb) were in for the control of plant parasitic nematodes (Maqbool and Hashmi, 1987). Current dissatisfaction with chemicals nematicides, due to safety issues, environmental concern and limited use of many products. However, the potential negative impact on the environment and ineffectiveness after prolonged use have led to a total ban or restricted use of most synthetic nematicide and an urgent need for safe and effective options (Zuckerman and Esnard, 1994). Several options are currently being assessed around the world to identify and develop ecologically sustainable management options for controlling nematode damage to plants.
In fact developing alternative to hazardous chemical nematicides is one of the top priorities for the future of nematology (Barker, 1994). Although many biocontrol agents like fungi, bacteria and nematodes are capable to suppress plant parasitic nematodes these have not been developed as successful commercial products due to the difficulties in their economic mass production and formulation techniques and also variability in field efficacy due to environmental stress (Warrior, 2000). Pasteuria spp., obligate parasites of plant-parasitic nematodes, has great potential as economically and environmentally friendly biological control agents. Pasteuria penetrans belongs to a group of endospore forming bacteria pathogenic to several genera of plant parasitic nematodes but the potential of P. penetrans as a bicontrol agent has mainly been investigated on root knot nematodes (Meloidogyne spp.,).When bacterium is added to soil in pots significant reduction in root knot nematodes has been attained (Gowen and Ahmed, 1990).
To reduce the use of synthetic nematicides and develop an alternative sustainable agro system for the management of root knot nematodes.
Survey and Sampling: A systematic survey was conducted in various vegetables growing areas [Faisalabad, Jhang, Khanewal (Mian Chano), Multan (Rawan), Rawalpindi, Lahore and Toba Tek Singh] for the collection of various root knot nematode isolates. Incidence of root knot nematodes on various vegetables was recorded. The association of Pasteuria penetrans with theses infested plants was also observed.
Processing of Samples: Root and soil samples were processed in laboratory. All the samples were stored in cool incubator. From soil samples population of root knot nematodes was assessed. These soil samples were also processed to see the presence of Pasteuria penetrans following standard techniques.
Results and Discussions
Out of 141 samples of cucumber 63 (44.68%) were infected with root knot nematodes and 51(39.53%) samples were found to be infected with RKN in case of tomato out of 129 samples. At now 85% of these samples are processed, analyzed and their populations are maintained in the pots.