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 experiments were carried out to evaluate certain bacterium, Pseudomonas fluorescens isolates regarding reproductive potential of root-knot nematode, Meloidogyne incognita, infecting tomato or eggplant. Results on tomato revealed that, on the basis of average total percentages nematode reduction, the over topped results were gained with P. fluorescens (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 bacterial treatments can be ranked in a descending order as follows: Pf9 > Pf4>Pf1and Pf7, as they achieved the highest average total percentages increases of 96.0, 47.3, 38.2and 29.8%, respectively compared to other treatments and untreated check. Regarding to eggplant, the over topped results observed was achieved by P. fluorescens (Pf10) which recorded the highest average total nematode reduction (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, averages were found in a descending order as follows: Pf1 (20.0%), Pf9 (18.7%) and Pf10 (18.3%) . It is worthy to note that the most distinct growth criteria was fresh weight of roots as it achieved higher percentage 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 biocontrol agent was efficient in controlling the root-knot nematode on tested plants.