Two field experiments were carried out at Agricultural Research and Experimental Station, Faculty of Agriculture at Noghtohor, kalubia. Egypt, during 1984/85 and 1985/86
seasons, to sutdy the effect of number of irrigations, N and p fertilization treatments on associated weeds grown with lentil. Each experiment included 24 treatments which
were the combination of four irrigation treatments and six fertilizer treatments.
Number of irrigations showed significant cf f.ct on f resh as well as dry weight of weeds/rn’ at different stages of growth in both seasons. The weight of weeds/rn’ signif i
cantly increased as the number of irrigations increased up to three times.
Lentil fertilization with N and P signfficantly increa sed weeds density, expressed as fresh and dry weight in lentil plots, but the unfertilized treatments showed the lowest fresh and dry weight of weeds/a’. The effect of the interaction between number of irrigation and NP fertilizers was not significant on all studied, characters.