EFFECT OF SOWING DATES AND NPK LEVELS ON ACTIVE SUBSTANCES IN SEEDS OF ISABGOL PLANTS (Plantago ovata Forsk, .L,).

Two field experiments were carried out in the Experimental Station and
Laboratory of the Vegetables and Floriculture Dept., Fac. of Agric., Mansoura Univ.,
during the winter seasons of 1995/96 and 1996/97. The investigation aimed to study
the effect of different sowing dates and NPK fertilization levels, as well as their
interactions on active substances extracted from Isabgol plant (mucilage contents).
Four sowing dates and six NPK levels were studied. The main findings in this
investigation can be summarized as follows:-

Plants grown in the first sowing date (Nov. 1^5t week) produced the highest
content of mucilage as g 1 5 g seeds or as percentage of mucilage per plant.

2. The addition of NPK fertilization significantly increased the mucilage seed
content and percentage per plant. The highest content and percentage were of
plants treated with the fourth level of NPK (178.0 g/3m\

Concerning effect of interaction between sowing date and NPK levels on
mucilage content, the highest content and percentage per plant were produced
from plants grown in the first sowing date and treated with the fourth level of
NPK.