The present investigation was carried out to study the efficiencies of agricultural  practices i.e. planting dates and tomato varieties on the population dynamics of tomato fruit worm, Helicoverpa armigera and tomato semilooper worm, Chrysodeixis chalcites at Kaha Research Station, El-Kalyoubia governorate during two successive seasons 2005 and 2006 where the results clearly showed a few number of eggs and larvae of H. armigera and C. chalcites in all tomatoes plantations. The abundance of H. armigera was relatively higher in the second season (2005/2006) than in the first season (2004/2005). The 3^rd planting date (15 September) had the lowest incidence of H. armigera and gave the greatest yields in both studing seasons. TH 348 variety showed the lowest population of both worms H. armigera and C. chalcites and gave the greatest yields.