Nematicidal Potentialities of Alginate Controlled-Release Formulations of Aldicarb and Cadusafos on The Root-Knot Nematode Meloidogyne incognita Infecting Tomato

Two separate pot experiments was conducted to evaluate the nematicidal activity of the alginate controlled release (CR) formulations of aldicarb (FA3, FA6 and FA9) and cadusafos (FC3, FC6 and FC9) versus the corresponding granule formulations against the root-knot nematode Meloidogyne incognita infecting tomato under green house conditions. The results indicated that all the tested formulations significantly reduced the number of galls, egg masses, and 2nd juveniles in the soil as compared with the untreated pots (control). On the other hand, the CR formulations of aldicarb and cadusafos could be reduced the galls, egg masses, and 2nd juveniles in soil significantly compared with their granular formulations. The percentage reduction in nematode galls for all the CR formulations of aldicarb and cadusafos were ranged from (95.1% to 96.04%) and (87.1% to 88.03%) for aldicarb and cadusafos, respectively. Whereas, the lowest percentage of reduction of the number of tomato galls was recorded with aldicarb and cadusafos granule formulation (61.3% and 66.71%), respectively. Also, the maximum reduction of the number of 2nd juveniles in the soil was achieved by the FA3 (86.73%) and FC3 (89.08%), while for its corresponding granule was (59.05% and 46.23%). It could be noted that the nematicidal efficacy of the CR formulations against M. incognita reached to approximately 1.77 folds by FA3 and 1.93 folds by FC3 comparable to the commercial formulations. The possible effects of different aldicarb formulations residues on the chemical constituents of tomato fruits were determined and recorded at the end of the experiment (72 days). The results obtained indicating that all the aldicarb and cadusafos formulations had significantly decreased of the b-carotene, lycopene, and ascorbic acid content of tomato fruits comparable to the untreated pots. No significant differences were found between all the aldicarb formulations and the control on the percentage of the total soluble solid (T.S.S.) whereas there were significantly increased in the percentage of T.S.S. of tomato plant treated with the CR cadusafos formulations. The FA3 and FC3 could be applied on tomato plant to control nematode with a minimum side effect on the quality control parameters such as lycopene, T.S.S. and ascorbic acid content of tomato juice compared with the commercial formulations.