The flax cultivar "Sakha l' was grown on a clay soil at the Experimental Farm,
Faculty of Agriculture, Kafr El-Sheikh, Tania University during 2000/2001 and
200112002 seasons. The alm was to study the effect of four nitrogen rates (30, 40. 50
and 60 kg N/fed.) and four harvesting times (140, 150, 160 and 170 days afte
sowing) on flax yield and lts attributes. Two fteld experiments were laid out In a spli
plot design wilh four replications. The main findings of this study can be summarize
as follOws: Increasing nitrogen rate from 30 to 60 kg Nlled. significantly increased stra"'1 and fiber yields and its related characters. l.e., technical stem length, main sterT1
diameter, straw yield/plant, total fiber percentage and fiber length as well as seed
yield and Its attributes, i.e., upper branching zone tength, number of capsules and
seeds/plant, seed yield/plant and 1000- seed weight. On Ihe contrary, seed 011 content
was Significantly decreased by increasing nitrogen rate. There was no significant
difference between 50 and 60 kg N/fed. in most studied traits, The oblained results reveal that harvesting date significantly affected all studied characters. except main stem diameter in both seasons. There was a continuous increase in straw, fiber and seed yields as well as their attributes with delaying harvesllng time from 140 to 170 days after sowing, except technical stem length and fiber length. which decreased significantly with delaying harvesting ti"le from 160 to 170 days after sowing. On the other hand, there was no significant difference between the third and fourth harvesting time (160 and 170 days after SOWing) in all studied traits, except technical stem length and fiber length. II could be concluded that application of 60 kg N/fed. and harvesting flax plants at 170 DAS could be recommended for optimum straw. fiber and seed yields/fed. Under the conditions of this investigation.