INFLUENCE OF TEMPERATURE AND OSMOTIC STRESS ON GERMINATION INDUCTION OF DIFFERENT CASTOR BEAN CULTIVARS

Among the different factors temperature and moisture are considered very important for germination, crop maturity and productivity. Experiments were conducted in the laboratory to determine the effect of temperature and moisture stress on the speed and total germination of four Castor bean cultivars (DS-30, PR-7/1, PR-101 and Local) obtained from two locations viz., Attock and Chakwal. The seeds were conditioned to different moisture content ranging from 0 to -14 bars and temperature ranging from 0 to 35 degrees C in hot air chamber/oven. The highest value indicated the fastest germination that was obtained from Attock location (3.992), in comparison with value (3.933) obtained from Chakwal when the Castor bean cultivars were incubated at 25 degrees C. The maximum GRI was recorded at the osmotic pressure of 0 bar (control), whose value in case of Attock seed location was 3.857 and Chakwal seed location (4.788). The interaction effects of moisture, temperature and cultivars were found significant for GRI. The cultivars performed differently under different temperature and moisture conditions.