Effect of Different Control Agents on Meloidogyne Incognita Kofoid Infesting Cucumber Plants

Abstract

The stock solution 10% and half stock solution 5% of three oils namely; mineral oil (Diver oil 97 % EC), plant oils marjoram oil (Origanum majorana L.) and orange oil (Citrus aurantium L.), as well as two species of bacteria Bacillus megaterium and BTS1 (Bacillus poylmyxa)at two concentrations showed that nematicidal activity against egg-mass and second stage juveniles of Meloidogyne incognitaKofoid in vitro experiments. Egg hatching and juvenile mortality were significantly (P ≤ 0.05) influenced by tested materials, concentration and exposure time. B. megaterium, diver oil and marjoram oil gave a higher effect, while B. poylmyxa was the lowest effective one. In case of juvenile mortality, B. poylmyxa, diver oil and marjoram oil gave the highest percentage of juvenile mortality (75.14, 73.00 and 61.85 %) after exposure at stock solutions (10%) and (53.00 , 67.42 and 52.57 %) with exposure to half stock solution (5%) after seven days of treatment, respectively. Under greenhouse conditions, results indicated that, oxamyl, dry leaf powder of moringa and B. megaterium were the most effective in suppressing root galling of M. incognita infectingcucumber plants. The maximum percentage of increase in shoot fresh weight was recorded on cucumber 43.26 and 25.36% in pots treated with oxamyl and B. megaterium, respectively. A moderate effect on treated eggs with the tested eco-friendly materials was observed on invasion and reproduction of M.incognita under greenhouse conditions. All tested materials significantly (P ≤ 0.05) reduced nematode parameters and increased cucumber plant growth parameters as compared with control treatment. Strongly decrease in number of egg masses and galls diameter was recorded in pots treated with oxamyl, moringa and B. megaterium followed by oils. Minimum number and gall diameter particularly ≥ 4mm was recorded in cucumber plants treated by oxamyl, moringa and B. megaterium. Data showed that moringa and B. megaterium could be used to increase crop yield of cucumber plants and for controlling root – knot nematode, M. incognita.