Nematicidal activity of some biopesticide agents and microorganisms against root-knot nematode on tomato plants under greenhouse conditions

A pot experiment was carried out under greenhouse conditions to study the impact of the evaluated treatments namely abamectin, azadirachtin 0.15%, azadirachtin 0.03%, Bacillus subtilis, Pseudomonas fluorescens, Paecilomyces lilacinus and oxamyl against root-knot nematode (Meloidogyne incognita) on the tomato plants cv. Super strain B. The results indicated that the most of the tested treatments obviously reduced root galls and remarkably increase tomato plant growth characters significantly and egg masses on root system, as well as, juvenile's numbers in the soil. P. lilacinus was the most effective treatment on both galls and egg masses achieving 88.23 and 76.94% reduction, respectively. While, less effective treatment was P. fluorescens achieving 57.53% galls reduction. Azadirachtin 0.03% was the least effective treatment giving 40.37% reduction of egg masses. The superior treatment that suppressed nematode populations was oxamyl recording (88.90%) followed by abamectin (78.69%) reduction. Moreover, azadirachtin 0.15% was the least effective treatment which recorded 60.15% reduction. On the other hand, plants free nematode recorded the highest plant parameters for shoot system length, fresh shoot weight, dry shoot weight and root system length with values of 24.15, 107.53, 211.59 and 46.17% increase, respectively. Azadirachtin 0.15% was the least effective treatment on shoot system length and fresh and dry shoot weight. While, oxamyl recorded the least increase in root system length estimated by 18.47%. B. subtilis recorded the highest increase in fresh root weight followed by P. fluorescens with value of 125.75 and 86.57%, consecutively. Vise versa, P. fluorescens was the superior treatment to increase the dry root weight by 68.14% followed by B. subtilis which recorded 35.40%. The least effective treatment in improving fresh root weight was azadirachtin 0.15% which recorded 54.85% increase. Regarding to dry shoot weight P. lilacinus and azadirachtin 0.15% were the least effective treatments with values of 8.85 and 2.66% reduction, respectively