Nematicidal Activity of Seed Powders of Some Ornamental Plants against Meloidogyne Incognita Infecting Pepper under Greenhouse Conditions

The present work was conducted to study the effectiveness of powdered seeds of six plant species namely: Brassica rapa, Eruca sativa, Juniperus communis, Lepidium sativum, Raphanus sativus, Sinapis alba on controlling Meloidogyne incognita infecting pepper plants cv. Top Star under greenhouse conditions. The application of S. alba seed powder overcome other treatments and accomplished the highest reduction percentages of nematode stages with the maximum values of 93.09, 93.94, and 95.75% for final nematode population, galls, and egg masses numbers, respectively at a rate of 6g/plant, while the least values were achieved by E. sativa seed powder with values of 67.88, 77.38 and 81.71 % for previous criteria, respectively at a rate of 2g/plant. There was a significant improvement in the plant characters (length, fresh weight & dry weight plant and leaf numbers). Among all treatments, the best plant growth character (plant length:143.1%, fresh weight:118.4%, dry weight plant:100.0%, and leaf numbers:99.5%) were observed with B. rapa grind seeds, followed by J. communis at a rate of 6g/plant. Increasing the used powdered seed rate from 4 to 6g/plant for S. alba and L. sativum cause a decrease in the plant growth parameters. Overall, all tested applications increased the percentages of chemical constituents i.e., nitrogen, phosphorus, and potassium concentrations, and phenol contents as well as decrease total chlorophyll percentages to a certain extent. The present study indicated the potential of screened plant seed powders to control M. incognita under greenhouse conditions and can be used as soil amendments after further investigations.