MANGEMENT OF MELOIDOGYNE INCOGNITA ON OKRA PLANTS USING NICKEL SULPHATE UNDER GREENHOUSE CONDITIONS

Impact of five nickel sulphate concentrations i.e. 1, 2, 4, 8 and 16 ppm as soil drench in comparison with oxamyl on plant growth parameters of okra plant (Abelmoschus esculentus) cv. Hyper Doki 1 infected with Meloidogyne incognita and its development was evaluated under greenhouse conditions at 30±3ºC. Results revealed that all tested treatments improved okra plant growth characters and reduced nematode criteria as well. In general, a gradual decline of plant growth increase was detected by the increase of tested nickel sulphate concentrations that accompanied with high percentage increase in reduction of nematode criteria. Among tested nickel sulphate applications, one ppm significantly overwhelmed other treatments in improving plant growth parameters with values of 31٫0, 38٫0 and 5٫3٪ for total plant length, fresh weight of the whole plant and shoot dry weight, respectively. Moreover, plant receiving 16 ppm / plant accomplished the highest reduction percentage in tested nematode parameters that averaged 82٫1, 67٫6 and 70٫7٪, for juveniles in soil, galls and eggmasses numbers, respectively. Meanwhile, oxamyl ranked first in suppressing nematode parameters with values of 94٫2, 90٫2 and 94٫9٪ for nematode population (J2), galls and eggmasses numbers as well as fourth in the increment of plant growth criteria, respectively.