EFFECT OF CERTAIN PSEUDOMONAS FLUORESCENS ISOLATES ON THE INFECTION OF ROOT-KNOT NEMATODE, MELOIDOGYNE INCOGNITA IN TOMATO AND EGGPLANT AND THE PLANT GROWTH

Abstract

Under screen house conditions, two experi-ments were carried out to evaluate certain bacte-rium, Pseudomonas fluorescens isolates regarding reproductive potential of root-knot nematode, Meloidogyne incognita, infecting tomato or egg-plant. Results on tomato revealed that, on the basis of average total percentages nematode reduction, the over topped results were gained with P. fluo-rescens (Pf2) which recorded the highest significant (P≤0.05) average nematode reduction (61.3%) and higher percentage reduction of females (77%) per plant. The second rank was obtained by Pf3 which reduced all nematode numbers as an average of 56.9%.On the basis of average total percentages plant growth and weight of fruit increases, four bac-terial treatments can be ranked in a descending or-der as follows: Pf9 > Pf4>Pf1and Pf7, as they achieved the highest average total percentages in-creases of 96.0, 47.3, 38.2and 29.8%, respectively compared to other treatments and untreated check. Regarding to eggplant, the over topped results ob-served was achieved by P. fluorescens (Pf10) which recorded the highest average total nematode reduc-tion (66.2%) with higher reduction of (J2s) in roots (89.9%) per plant and in soil (78.8%) per pot. The second rank was obtained by Pf9 and Pf2 where they reduced all nematode numbers as averages of 55.9% and 54.9%, respectively. Also Pseudomonas isolates enhanced the plant growth of eggplant, av-erages were found in a descending order as follows: Pf1 (20.0%), Pf9 (18.7%) and Pf10 (18.3%). It is wor-thy to note that the most distinct growth criteria was fresh weight of roots as it achieved higher percent-age increase (58.1%) by using Pf9 followed by Pf1 as it caused 40.6% increase compared to untreated check. The highest average percentage of fresh weight of shoot were recorded for Pf10 (26.4%) and Pf8 (22.1%). Whereas for dry weight Pf3 (29.8%) and Pf2 (19.1%). In conclusion, the tested biocon-trol agent was efficient in controlling the root-knot nematode on tested plants