Greenhouse experiment on the influence of dried leaf powder of marigold or horse manure or Baciilus thun‘ngiensis in comparison with oxamyl against citrus nematode, Tyienchuius semipeneirans infecting lemon plant, Citrus Limon l. under greenhouse conditions revealed that oxamyl surpassed all treatments tested in increasing plant growth parameters with values of 166.02% and 131.03% for total plant fresh weight and shoot dry weight, respectively. Meanwhile, B. thun‘giensr‘s ranked second to oxamyl and accomplished the best performance in improving fresh weight of whole plant and shoot dry weight, followed by horse manure application and then marigold powder comparing to nematode alone. On the other hand, oxamyl treatment also surpassed other treatments tested in suppressing nematode population (73.02%) followed descendingly by B. thuringiensis (72.37%) and then horse manure (69.54%) and marigold powder (66.96%). Moreover, all tested components showed significant increase in N, P, and K concentrations in shoot of lemon plants exceeding those of nematode alone. Moreover, the previous treatments clearly increased the total chlorophyll content of lemon plant with range from 80.72% for nematode alone to 2.18% for marigold powder. Moreover. nematode infection without any component added showed the highest record of total chlorophyll content (1996.5 mgig) as compared to all materials tested .