The current research was conducted at Tissue Culture laboratory of Vegetables and Ornamental Dept., and greenhouse of Nematology Research Unit, Agricultural Zoology Dept., Faculty of Agriculture, Mansoura Univ., Egypt. The effect of certain components i.e. L-glutamic acid, ascorbic acid, yeast extract and phenylalanine introduced singly at 1 g/ L added to MS medium used for the growth of the carnation seeds, obtained from France before transplanting into plastic pots filled with sterilized loamy sandy soil on Meloidogyne incognita infection was evaluated under greenhouse conditions at 22±5°C. Results indicate that among tested treatments, application of L-glutamic acid gave the highest reduction percentage in M. incognita root galls by 57.14% while ascorbic acid ranked first in respect to egg-masses with value of 65.25%. However, Yeast extract exceeded other tested components in percentage increase of the whole plant fresh and shoot dry weights of the infected carnation seedlings and uninfected plants as well with values of 99.09 and 53.33%; and 55.96 and 211.8%, respectively. Thus, it could be concluded that yeast extract or L-glutamic acid applied in MS medium considered the best treatments in improving growth of carnation plants, increasing growth and suppressing M. incognita development and reproduction under greenhouse conditions.